Clostridium difficile infection in inflammatory bowel disease: risk factors, recurrence and outcome

1 2 3 4 5 UNIVERSIDAD DE LAS PALMAS DE GRAN CANARIA DEPARTAMENTO DE CIENCIAS MÉDICAS Y QUIRÚRGICAS TESIS DOCTORAL CLOSTRIDIUM DIFFICILE INFECTION IN INFLAMMATORY BOWEL DISEASE: RISK FACTORS, RECURRENCE AND OUTCOME Tesis Doctoral presentada por Dña. Mónica Peñate Bolaños Dirgida por el Dr. D. Alberto Monescillo Francia Codirigida por la Dra. Maria del Mar Ojeda VargasEl director El director El codirector El doctorando Las Palmas de Gran Canaria, 2015 6 7 UNIVERSIDAD DE LAS PALMAS DE GRAN CANARIA DEPARTAMENTO DE CIENCIAS MÉDICAS Y QUIRÚRGICAS Ph. D. DISSERTATION CLOSTRIDIUM DIFFICILE INFECTION IN INFLAMMATORY BOWEL DISEASE: RISK FACTORS, RECURRENCE AND OUTCOME MÓNICA PEÑATE BOLAÑOS Las Palmas de Gran Canaria, 2015 8 9 Acknowledgments To my promotors: Dr. Alberto Monescillo Francia Dra. Mar Ojeda Vargas To Dra. Elena Jiménez Mutiloa To Dr. Jose Miguel Marrero Monroy To Dr. Angel Sierra Hernández To Julia Foster To my colleagues To Dr. Esteban Perez Alonso And finally, to my patients for teaching me every day to be a better person I have a dream…. Martin Luther King, 1963 16 17 Contents 1. GENERAL INTRODUCTION ................................................................................................................ 23 2. CHAPTER 1: THEORETICAL FRAMEWORK: CLOSTRIDIUM DIFFICILE AND IBD .................................... 29 2.1 INTRODUCTION ..................................................................................................................................... 29 2.2 WHAT IS CLOSTRIDIUM DIFFICILE? ............................................................................................................ 30 2.3 RELATIONSHIP BETWEEN CLOSTRIDIUM DIFFICILE AND INFLAMMATORY BOWEL DISEASE ...................................... 32 2.4 CONTRASTING CLOSTRIDIUM DIFFICILE INFECTION IN IBD PATIENTS AND GENERAL POPULATION ............................ 34 2.4.1 Overview ....................................................................................................................... 34 2.4.2 Clinical presentation ...................................................................................................... 34 2.4.3 Risk factors .................................................................................................................... 35 2.4.4 How does CD influence in the IBD outcome? .................................................................. 38 2.4.5 May recurrent CDI be a severe problem as in no-IBD population? ................................. 40 2.5 HOW CAN WE DIAGNOSE CDI IN IBD PATIENTS? ......................................................................................... 43 2.5.1 Laboratory test .............................................................................................................. 43 2.5.2 Biological parameters.................................................................................................... 47 2.5.3 Faecal markers .............................................................................................................. 47 2.6 IS THE TREATMENT THE SAME AS GENERAL POPULATION? .............................................................................. 48 2.6.1 Overview ....................................................................................................................... 48 2.6.2 Treatment decision based on stratification by disease severity ..................................... 51 2.6.3 What is the best approach in the recurrences? .............................................................. 52 2.6.4 Role of FMT in the treatment of recurrent and refractory CDI ....................................... 53 2.6.5 What is coming up: future treatments ........................................................................... 55 2.7 GENERAL RECOMMENDATIONS FOR THE PREVENTION AND CONTROL OF CDI ..................................................... 57 3. CHAPTER 2: STUDY ........................................................................................................................... 61 3.1 AIMS .................................................................................................................................................. 61 3.2 METHODOLOGICAL SECTION .................................................................................................................... 61 4. CHAPTER 3: RESULTS ........................................................................................................................ 67 4.1 DISTRIBUTION OF CDI EPISODES ............................................................................................................... 67 4.1.1 Positive episodes distribution during the period of our study ........................................ 68 4.1.2 Positive episodes distribution comparing with general population ................................ 69 4.1.3 Total requested samples in IBD patients compared with positive final results ............... 70 4.2 TIME IT TOOK TO DIAGNOSE OUR PATIENTS ................................................................................................. 71 4.3 CASE-CONTROL STUDY ............................................................................................................................ 73 4.3.1 General characteristics of episodes ................................................................................ 73 4.3.2 Laboratory parameters .................................................................................................. 89 18 4.3.3 Treatments at the moment of episodes ......................................................................... 95 4.3.4 Risk factors .................................................................................................................... 98 4.3.5 Independent risk factors for CDI episodes .................................................................... 102 4.3.6 Outcome ...................................................................................................................... 103 4.3.7 CDI treatments ............................................................................................................ 105 4.3.8 Analysis in the subgroup of patients with age > 65 ...................................................... 107 4.4 RECURRENT EPISODES OF CDI IN IBD PATIENTS ......................................................................................... 114 4.4.1 General picture of recurrent episodes in CDI patients .................................................. 114 4.4.2 Characteristics of recurrent episodes and comparison of UC and CD ........................... 119 4.4.3 Independent risk factors for recurrent CDI episodes .................................................... 125 5. CHAPTER 4: DISCUSSION OF RESULTS ............................................................................................ 133 6. CHAPTER 5: CONCLUSIONS ............................................................................................................ 147 7. CHAPTER 6: OUR PROPOSALS TO MODIFY THE MANAGEMENT OF CDI .......................................... 151 8. APPENDICES ................................................................................................................................... 157 TABLE 1: CLINICAL FEATURES CDI ................................................................................................................ 157 TABLE 2: PROGNOSTIC MARKERS WE CAN USE TO DETERMINE THE RISK OF DEVELOPING A SEVERE CDI ....................... 157 TABLE 3: PROGNOSTIC MARKERS WE CAN USE TO DETERMINE RISK OF RECURRENT CDI ........................................... 158 TABLE 4: RECOMMENDATIONS ON ORAL AB TREATMENT OF FIRST EPISODE OF NON-SEVERE CDI .............................. 158 TABLE 5: RECOMMENDATIONS ON ORAL ANTIBIOTIC TREATMENT OF INITIAL SEVERE CDI ........................................ 159 TABLE 6: RECOMMENDATIONS ON ORAL ANTIBIOTIC TREATMENT ....................................................................... 159 TABLE 8: RECOMMENDATIONS ON NON-ANTIBIOTIC TREATMENT........................................................................ 160 TABLE 9: RECOMMENDATIONS ON NON-ORAL ANTIBIOTIC TREATMENT OF INITIAL CDI: MILD AND SEVERE DISEASE ....... 161 TABLE 10: RECOMMENDATIONS ON ALTERNATIVE TREATMENTS FOR FIRST EPISODE OF CDI ..................................... 161 9. BIBLIOGRAPHY ............................................................................................................................... 165 10. RESUMEN EN ESPAÑOL ................................................................................................................ 179 19 Abbreviations IBD: Inflammatory bowel disease C. difficile: Clostridium difficile C. diff: Clostridium difficile CDI: Clostridium difficile infection CD: Clostridium difficile CD: Crohn´s disease UC: Ulcerative colitis FMT: Faecal microbiota transplant IM: Immunomodulators AB: Antibiotic 20 21 General introduction 22 23 1. General introduction Clostridium difficile infection (CDI) in inflammatory bowel disease (IBD) patients is a fascinating subject. Clostridium difficile (CD) is a cause of diarrhoea in humans for more than 30 years, and its incidence has been increasing in the last decade. Since the early 2000s, severe CDI outbreaks in hospitalized patients in North America and Europe have put in check to the health authorities, and it has become a serious health problem with a high rate of complications and mortality. Newspapers and television have covered the major Clostridium difficile outbreaks in the UK and North America. Recently, in September 2015, the first faecal bank for recurrent CDI treatment has been created in the USA. It provides clear evidence that the number of people contracting this hardtocontrol and treat bacterial infection is increasing. What is Clostridium difficile and why is so hard to control and treat? CD is the most frequent cause of diarrhoea in hospitalized patients and antibioticassociated colitis. It is a Grampositive bacteria, strict anaerobic and sporeforming. Spores are easily spread via airborne and can persist under adverse conditions for a long time. It can contaminate hospital environment by spread through health care workers and suboptimal environmental cleaning practices. CD lives harmlessly in the gut of 10% to 15% of adults under normal conditions without causing symptoms (colonization). However, when the balance of intestinal flora is disrupted, often following a course of antibiotics, it may produce a wide spectrum of clinical manifestations ranging from asymptomatic carriage and uncomplicated diarrhoea to a severe, lifethreatening infection. In the last decade, the severity and mortality have increased, due to more virulent strains (e.g. B1/NAP1/027) resistant to conventional antibiotics treatments. Thus, we have had many problems with the treatment and the prevention onset new infections and recurrences. Treatment includes infection control measures. Antibiotic therapy should be initiated as soon as possible, and faecal microbiota transplantation can constitute another alternative treatment for recurrent and severe Clostridium difficile infection (CDI). Which patients are at risk to be affected by CD? It had been believed that the typical profile of a patient with CD was a hospitalized and elderly patient, undertaking antibiotics, with chronic diseases and immunodeficiency. However, the number of people who contract it is increasing out of hospitals. The antibiotics exposure is neither necessary nor 24 sufficient for it, for the first time, an increased incidence of CD in children and pregnant women has been described. A group particularly susceptible to CDI is inflammatory bowel disease (IBD) patients (Crohn's disease and ulcerative colitis) especially those with involvement of the colon. IBD patients with CDI tend to be younger, have less prior antibiotic exposure and in most cases had a community acquisition. Consequently, IBD patients have a different risk profile compared with general population. Which is the relationship between Clostridium difficile and inflammatory bowel disease? May CDI be as dangerous as in the general population? The relationship between CD and IBD is controversial. It is still not clear whether CD is an etiologic cause or a consequence. It is unknown whether the problem is caused by an alteration of the local immune system in the intestine or the systemic inflammatory state or both. CDI can play an important role in the clinical initiation of IBD, can produce a delay at IBD diagnosis and can be a challenging factor in the differential diagnosis of relapses. CDI adds difficulties in IBD therapeutic management because it needs a specific antibiotic treatment. Several studies in IBD have demonstrated a rising in the severity and rates of recurrence, both associated with an increase in morbidity, surgeries and mortality. Could the recurrence of CDI be a problem in IBD patients? Which would the best therapeutic approach be? The recurrences may be a problem after a first treatment in nonIBD and IBD patients, around 30% in both. In IBD, the investigation of CD in stools sample is recommended in the relapses resistant to conventional treatment in outpatient and all inpatients, based on clinical practice European, American and Spanish Guidelines. However, there are not specific recommendations for the treatment in this patients. Nowadays, we treat our IBD patients based on Microbiology Guidelines. For this reason, it would be important that we had specific protocols for the best treatment strategies in IBD patients specifically. We have performed a retrospective, casecontrol study to evaluate the following points in our country: How have the number of IBD patients with CDI changed in the last 8 years? 25 Which are the risk factors for CDI in IBD patients with a relapse in our country? Is the recurrence frequent in our patients? How do we treat them? How do we treat CDI in our IBD patients? How does CDI affect the outcome of IBD? Our study is the first made in the Canary Islands about CDI in IBD patients to add experience in the risk factors, recurrence and outcome. We need to know the implications of this infection in IBD patients with a relapse in our country. To attempt to answer those questions, the outline of this thesis is: Chapter 1: Theoretical framework, includes an update of most important aspects that contribute to understanding this study and its results. Special attention is given to the influence of Clostridium difficile on inflammatory bowel disease. Chapter 2: Study: Aims and method section Chapter 3: Results Chapter 4: Discussion Chapter 5: Conclusions Chapter 6: Our proposals to modify the management of CDI in IBD patients in our area, according to our study Appendices Bibliography Summary in Spanish 32 increased exotoxin production, and its antibiotic resistance profile. It has been involved in recent hospital outbreaks and communityacquired infections. Since 2003, several European countries and Canada have notified cases of C. difficile 027associated disease. This fact demonstrates its rapid dissemination and generate concern among health and no health professionals. After 1977, several studies discovered two potent toxins produced by CD and rather than the organism, were responsible for significant and sometimes severe inflammatory changes in the colon. Only toxigenic strains with a pathogenicity locus (PaLoc) cause disease: enterotoxin A (TcdA) and cytotoxin B (TcdB). (16) In addition to the two toxins (TcdA and TcdB), some strains of Clostridium difficile also produce an actinspecific ADPribosyltransferase, called binary toxin (CDT) (4%). (17) Enterotoxins A and cytotoxin B play a major role in its pathogenesis, and the detection of these toxins in gut content has been the gold standard for diagnosis for many years. However, CRP ribotype 017, one of five clonal lineages of humanvirulent C. difficile, lacks TcdA expression but causes widespread disease. (1820) In general, the factors that mediate the disease include the dose and toxigenic of the colonizing strain, its ability to adhere to the colonic epithelium (infects the internal lining of the colon), the presence of others organisms that affect its multiplication and toxin production and the susceptibility of the host. This produces a disruption of the tight junctions, inflammation and damage to the intestinal mucosa, with the characteristic “volcanic eruption” observed in pseudomembranous colitis. Hypervirulent strains, such as ribotype 027, has been described worldwide. It expresses the binary toxin, which damages human cells by inhibiting actin polymerization (21) and encodes a TcdC mutation that results in a truncated, inactive TcdC protein. This results in unsuppressed and unregulated toxin production, and levels of toxins A and B are 16 and 23 times higher in patients with this strain (hyperproduction of toxins A and B). (22) The dissemination of this strain in North America and Europe could change the epidemiology of C difficileassociated disease. (23) In 2003, in Quebec (Canada), a strain of CD resistant to fluoroquinolones, with the binary toxin and an incomplete deletion of the tcdC gene caused an outbreak. (24) McEllistrem et al. (25) found that the severity of CDI was not associated with a particular clone or underlying disease, but it could associate with the presence of the binary toxin genes. In this study, the binary toxin genes were detected in approximately 5% of CD strains. 2.3 Relationship between Clostridium difficile and inflammatory bowel disease Inflammatory bowel disease (IBD) is a chronic, immunemediated disease of the gastrointestinal tract that develops in genetically susceptible individuals. However, in the pathogenesis of IBD, the alteration in the intestinal microflora may disrupt its homeostasis. Dysbiosis in IBD predisposes to colonization with C. difficile. There is a higher proportion of asymptomatic carriers in IBD than in the general population. (26) In the past, it was not thought that CDI in IBD patients was relevant. In fact, 33 Rolny et al. in 1983 did not recommend to investigate CDI in IBD patients with a relapse. The frequency of CDI in IBD patients has doubled or tripled since 2001. We do not know whether CD is a cause of IBD or a consequence of the inflammatory state in the intestinal environment and disruption of the normal microbiota. Although it had not been possible to demonstrate that Clostridium difficile played an etiologic role in the IBD pathogenesis, it was demonstrated it played a role in relapses. (27) CD can promote relapsing of CU by activating the immune response. CD toxins may mediate mucosal inflammation, together with cell wall components of the microorganism. Innate and adaptive host responses to CD toxins and the role of mucosal changes in IBD may increase the inflammatory response in the presence of CDI. Thus, the restoration of intestinal flora and colonization resistance is thought to be the mechanism responsible for the treatment of recurrent CDI (28) and on the other hand, infliximab treatment can be useful and protective due to this activation of the immune response. (29) IBD is one of the strongest comorbidities associated with the possibility of CDI. (30) Patients with IBD have a higher incidence of CD in comparison with the general population. (31, 32) CDI is important in the clinical initiation of IBD. The prevalence of CDI in newly diagnosed IBD patients is high (8.110%) and is independent of the type of disease. The risk of CDI in new onset paediatric IBD was associated with an increase in the age of the patient and the severity of the disease (33, 34) but the specific risk factors reported in adults were not identified in children, suggesting the possible involvement of other mechanisms for acquiring the pathogen. (35) However, questions about the role of infections in the development and exacerbations of inflammatory bowel disease remain unanswered. Last years have increased the research of the role of intestinal microflora in the pathogenesis of IBD. (18) Gut microbiota plays a role in the initiation of CDI in IBD patients by producing superinfection but also as causative agent. (36) The normal gut flora acts as a colonization barrier that protects against CD and this function may be compromised when gut flora is disturbed. The risk of CDI affects the colon, increases with use of cephalosporin and the presence of gastrointestinal feeding devices. These are important risk factors for communityassociated CDI in children. (37) Hourigan et al. (38) studied the changes in the microbiota in children with IBD and CDI compared with children with CDI without IBD. They found that children with IBD presented more alterations of their microbiota compared with nonIBD children. Moreover, after CDI treatment with faecal transplantation (FMT) in children without IBD the microbiota restoration was complete and in those with IBD, bacterial diversity returned to preFMT baseline by 6 months, suggesting IBD host related mechanisms modify faecal microbiome diversity. 34 2.4 Contrasting Clostridium difficile infection in IBD patients and general population 2.4.1 Overview Over the past two decades, there has had an increase worldwide in incidence and severity of CDI in the general population and paralleling in IBD. The emergence of a hypervirulent strain in the early 2000s associated with an increase in the number and severity of CDI episodes in the US, Canada, and other countries has changed the management of CDI. The appearance of the NAP1/BI/O27 strain in the early to mid2000s has been associated with more severe forms of CDI. Outbreaks have not been described in IBD patients until now. 2.4.2 Clinical presentation CDI is a cause of antibioticassociated diarrhoea. The prevalence of CDI in IBD patients has increased over last decades. CDI incidence in IBD has increased and it is higher than in nonIBD population. The increase in the number of cases may reflect an increase in the rising incidence of CDI in general or increasing the virulence of the organism as we have just commented previously. Clostridium difficile (CD), specifically its toxins, have been implicated as a risk factor for exacerbation of the inflammatory process in up to 5% of patients with ulcerative colitis or Crohn´s disease. (39) Clinically, CDI may range from an asymptomatic carrier state to serious lifethreatening colitis. The symptoms may develop within 48 to 72 hours after infection or may be delayed for 2 to 3 months, usually after the administration of antibiotics (in some cases, only a single antibiotic tablet may lead to severe disease). Clinical symptoms of CDI and an exacerbation of inflammatory bowel disease are clinically indistinguishable.(40) Therefore, an early suspicion is essential to start antibiotic treatment with/without corticosteroids.(41) On the other hand, endoscopy rarely shows pseudomembranes and it is useless for diagnosing CDI in IBD.(42) Pseudomembranes and fibrinopurulent eruptions are not seen endoscopically or histologically.(43, 44). BenHorin et al. (45) evaluated the rate of pseudomembranes in IBD patients, identifying predictive factors for pseudomembranes' presence and assessing its clinical impact. This study documented that hospitalized IBD patients with CDI had low rates of endoscopic pseudomembranes, which were not produced by the use of immunosuppressant drugs. IBD patients with CDI and pseudomembranes presented more commonly fever, but their clinical outcome was similar to patients without pseudomembranes. 35 2.4.3 Risk factors IBD patients The traditional risk factors for CDI, in the general population include: hospitalizations, antibiotic use, older age and severe comorbidities. Moreover, infection with ribotype 027 predicts severe CDI and higher mortality and the use of antibiotics is a modifiable risk factor for severe CDI.(46) Contrasting, IBD patients have different characteristics: younger age, community acquisition, lack of antibiotic exposure, colonic IBD, and corticosteroids use. CDI can occur in the small bowel, in UC patients with an ileal pouchanal anastomosis after a colectomy.(40) Most studies have demonstrated that patients with inflammatory bowel disease (IBD) have a higher incidence of CD compared with the general population.(31) IBD and UC, in particular (colonic involvement), are the comorbidities most strongly associated with the possibility of CDI.(30, 47) In contrast, a study in German in 2011 found that a low percentage of hospitalized patients with relapses had CDI (48) and another performed in 2013 by Penders et al. (49) found that CD was not a common trigger for exacerbations of IBD in clinical in the Netherlands. Most of IBD patients appear to contract CD as outpatients. CDI confirmed within 48 hours of admission, suggesting a community acquisition.(39, 42, 43) However, it can occur in hospitalized adults and children: among children, the rate of CDI was over 12 times higher in IBD than nonIBD hospitalizations and, among adults the rate of CDI was four times higher in IBD than nonIBD hospitalizations. In adults, CDI was significantly higher in ulcerative colitis (UC) than Crohn's disease but in children there was no differences between UC and CD (50). The incidence of CDI is 1.85.7% in hospitalized patients with ulcerative colitis (UC) (29). Sandberg et al.(51) found CDIrelated hospitalizations were associated with longer lengths of stay than hospitalizations without CDI in children and young adults with IBD in the United States. Colonization of the small bowel occurs more frequently in IBD patients with ilealanal pouch anastomosis after colectomy. Smallbowel bacterial flora, such as the neoterminal ileum, is colonized by colonic type bacterial flora, which may make it susceptible to overgrowth with C. difficile, particularly with concomitant antibiotic treatment. Chronic or refractory pouchitis and cuffs can appear due to CD colonization. Surgeries involving only the left side of the colon with preservation of the ileocecal valve do not increase the risk of CDI of the small bowel. Other risk factors for CDI in IBD patients are: malnutrition, anaemia, HIV infection, dementia, immunosuppressed treatment, antibiotic exposure and proton pump inhibitors.(30, 43, 52) 36 Children with IBD, similar to adults, have an increased risk of acquiring a Clostridium difficile infection. CDI represents a significant healthcare burden in hospitalized children with IBD. (5355). Paediatric patients with CD tend to have active colonic disease and a more severe disease course. (55, 56) Rate of recurrent CDI in children was 22%, independent of the type of IBD, and was significantly associated with: malignancy, recent surgery, and the number of antibiotic exposures. Wultanska et al. (57) and Bossuyt et al. (58) did not find significant correlation between CDI and IBD therapy. Other authors found immunosuppressant treatment as risk factors. (42, 59) The latest risk factors: In 2012, Shakir et al.(60) studied serum antibodies against C. difficile toxins for the first time. They were detected in susceptible populations and could be protective. However, these antibodies had not been studied in IBD patients. This study measured immunoglobulin G antibody levels to CD toxin B in serum from IBD patients in remission and IBD patients in relapse. IBD patients demonstrated significantly higher antibody levels than nonIBD patients. Also, more proportion of IBD patients in remission had positive antibody levels compared with IBD patients in relapse. The authors concluded that the characterization of antibody responses could improve our understanding of susceptibility to CDI among IBD patients. Connelly et al.(61) identified a singlenucleotide polymorphisms (SNPs) associated with CDI among IBD patients. The interleukin4 geneassociated SNP rs2243250 was strongly associated with CDI in IBD population. Thus, SNP could allow for the identification of IBD patients at greater risk for CDI. Ananthakrishnan et al.(62) found that the therapeutic supplementation of vitamin D could be useful to prevent CDI. Plasma calcifediol [25(OH)D] stimulates the production of cathelicidins. Cathelicidins are antimicrobial peptides that attenuate colitis and inhibit the effect of clostridial toxins. The authors found that a higher plasma calcifediol [25(OH)D] was associated with reduced risk of CDI in patients with IBD. 37 Non-IBD patients Most wellknown risk factors for CDI in the general population are: antibiotic use (19, 37, 63 74), older age (>65) (19, 65, 73, 7577), immunosuppressant treatment (19), immunocompromised patients (66, 78, 79), proton pump inhibitors (73, 80, 81), intensive care unit (75, 82), mechanical ventilation, prolonged hospital stay (65, 83), chemotherapy (79, 84), solid organ transplant (85), malignancies (79, 82), surgeries (antibiotic prophylaxis) (81), dialysis (86, 87), gastrointestinal surgery, nasogastric tube placement (19), contact with infected patients (88, 89), nutritional status (70, 76), diabetes (73, 90) In HIV infection, low gammaglobulin levels and low albumin levels at admission are associated with an increased risk of developing CDI. A deficiency in humoral immunity appears to play a major role in the development of CDI. (91) A traditional risk factor for CDI include hospitalization but a study performed in Brazil found 81% of CDI community acquired. (92) Other risk factors described more recently are: C. difficile is an important cause of healthcareassociated diarrhoea among paediatric patients. It was found that more than threequarters of cases (75%) of CD were contracted in the community, not in the hospital. The incidence of CDI in children was 12 times higher between 2004 and 2009, compared with the period between 1991 and 1997 (32.6 cases per 100,000 vs. 2.6). (93) Fiedoruk et al. (94) determined CD were the main causative agent of communityacquired acute diarrhoea in children (14.8% of children aged >1 year). Peripartum women appear to be another population susceptible to CDI. The use of a combination of antibiotics remained a significant independent risk factor. (95) Van der Wilden et al.(96) found a significant inverse association between 25(OH) D3 levels and CDI severity in hospitalised adults. Further studies are needed to demonstrate whether vitamin D supplementation can improve outcomes in patients with CDI. Perioperative antibacterial prophylaxis: 1.5% of patients who received perioperative antibacterial prophylaxis developed CDI. The independent risk factors associated with CDI were: older age, administration of Cefoxitin alone or in combination with another antibiotic and years of surgery. (97). Clayton et al.(98) studied outbreak CD in a residential home in the UK. They found CDI affected residents had received a mean of 2.7 antibiotic courses in the two months preceding diagnosis. However, the investigation of the facility discovered problems with hand hygiene and environmental cleaning. The authors concluded that we need a health and socialcare systems working together to assure the 38 safety of people in their care. Zarowitz et al. (89) studied the incidence of CDI in nursing home residents and concluded that was high because of: decreased the immune response, multiple comorbidities, treatments, increased risk of infection, the proximity of residents, and recent hospitalization. Patients with toxigenic CD colonization are at risk of developing CDI. Rates of asymptomatic CD colonization on hospital admission range between (1.421%). There are three main risk factors for C. difficile colonization: recent hospitalization within 3 months, chronic dialysis and corticosteroid use. (99) Lin et al.(100) found that risk factors for the development of CDI among hospitalized patients were: diabetes mellitus and recent piperacillintazobactam or PPIs treatments. Kong et al.(101) evaluated host and bacterial factors associated with colonization on admission. The hospitalization within the last 12 months, use of corticosteroids, prior CD infection, and the presence of antibody against toxin B were associated with colonization on admission. Vitamin D [25(OH) D] has immune modulatory effects and plays a role in intestinal immunity. Low serum 25(OH) D < 15 ng/mL was associated with increased risk of CDI. This suggests vitamin D may have a role in determining susceptibility to CDI in outpatients.(102) Another study in adult patients to investigate whether preadmission 25hydroxyvitamin D (25(OH) D) levels are associated with the risk of hospitalacquired CDI, found vitamin D status before hospital admission was inversely associated with the developing CDI. These data support the need for randomized, controlled trials to test the role of vitamin D supplementation to prevent CDI.(103) 2.4.4 How does CD influence in the IBD outcome? Although a considerable number of studies support a substantial increase in incidence, severity, and health care costs for Clostridium difficile infection (CDI) in inflammatory bowel disease (IBD), only a few have evaluated its impact on IBD outcome. Most studies showed that IBD patients with CDI present higher proportion of worse outcome than those without CDI. These patients had a longer length of hospital stay, higher rates of colectomies, and increased mortality. Patients with ulcerative colitis were more susceptible to CDI and had more severe outcome than those with Crohn's disease. (39, 40, 42, 43, 104106) Ananthakrishnan et al. (107) found that had an increase nationwide in CDI complicating IBD hospitalizations between 1998 and 2007. During 20042005, more than half of the infected IBD patients required hospitalization, and 20% required colectomy.(43) From 2005 to 2010, CD colitis had doubled in North America with an increase in the morbidity and mortality in IBD patients.(108) CDI in patients with IBD associated with higher rate of recurrence (34%) and with higher morbidity than in the general population. Patients with IBD required more hospitalization (57%) and 39 escalation of therapy (67%) (immunomodulators/biologic treatments) following CDI, suggesting that CD increased severity of IBD.(31) Kaneko et al.(47) did not find association with any demographic factor or colectomy rate. However, CDI eradication therapy allowed some refractory patients to withdraw from steroids. Several reported cases with infliximab therapy have provided favourable outcomes in UC patients with CDI, suggesting that infliximab treatment may be protective; however, the optimal infliximab treatment regimen for UC patients with CDI remains to be established.(29) Most studies have focused on demonstrating that CDI is associated with adverse outcomes in IBD patients. However, few studies have attempted to identify predictors of severe outcomes associated with CDI in IBD patients: serum albumin <3 g/dL, haemoglobin < 9 g/dL and serum creatinine >1.5 mg/dL were independent predictors of severe outcomes in hospitalised IBD patients with CDI.(109) Often, there is no evidence of colonic changes with CD infection, including pseudomembranous exudate. However, a severe clinical course may occur, including toxic colitis and toxic megacolon. Hypervirulent CD strains have been reported raising concern for a more severe disease in IBD patients. Furthermore, small bowel involvement or CD enteritis has been increasingly described, usually in those patients with colectomy or total proctocolectomy for severe and extensive IBD. Furthermore, refractory or treatmentresistant pouchitis may occur with CDI.(18) In a study from 2000 to 2008 most patients had a successful outcome and only one patient with UC needed a semiurgent colectomy. The use of immunosuppressive drugs in IBD did not seem have a negative influence in the outcome but CDI appeared to be associated with escalation of medical therapy in the year following to the infection. (58) Moreover, CDI and severe disease on endoscopy seemed to be associated with an increased risk of subsequent colectomy on longterm followup.(110) There is an apparently adverse outcome associated with the use of combined antibiotics and immunosuppressant treatment, particularly corticosteroids compared with antibiotics alone. BenHorin et al. (111) in a retrospective cohort study from European centres found 12% of patients with antibiotic treatment and immunomodulators presented: death or colectomy within 3 months of admission or in hospital, systemic complications, megacolon and bowel perforation compared with none of 51 given antibiotics alone. The treatment with one or more immunomodulators increased the risk of having an adverse outcome independent of disease severity at presentation (OR 17; 95% CI 3.291). CDI has associated with worse outcome among hospitalized children, including increased risk of death. Vendetti et al. (112) identified risk factors for allcause inhospital mortality among children with CDI. Select chronic conditions and more severe diseases increased possibility of death. 40 In conclusion: CD can imitate an IBD relapse. Thus, it is essential that physicians are vigilant (58) Early suspicion is the best strategy to prevent complications related to CDI. In a recent study, Axelrad et al. (113) studied the use of nursing admission workflow to increase the rate of CDI diagnosis for inpatients with IBD with a relapse. There was a significant increase in the diagnosis and patients who received a test were more likely to have CDI, shorter hospital stays, and fewer readmissions. 2.4.5 May recurrent CDI be a severe problem as in no-IBD population? Patients with IBD are at increased risk of developing C. difficile infection, have worse outcomes of CDIincluding higher rates of colectomy and death, and experience higher rates of recurrence. In fact, clinical practice based on European, American, and Spanish guidelines recommend in all relapses, investigate in stools samples the presence of CD toxins in IBD out and inpatients but do not incorporate a section on this aspect. It would be important; we had a protocol with the best treatment strategies in this situation. We are going to review the novel and innovative treatment strategies to reduce treatment costs and prevent recurrence of CDI. Despite effective antibiotic treatments, recurrent infections are common. Recurrence or relapse is not commonly due to development of antibiotic resistance of the CD, but it is considered to be due to a defective host immune response, persistence of spores in the gastrointestinal lumen after discontinuation of antibiotics, failure to reestablish intestinal flora or to reinfection by a new strain of CD. (114) Humoral immune response as a predictor of recurrence in Clostridium difficile infection. Low serum concentrations of antibodies directed against the toxins TcdA and TcdB have been associated with a higher risk of recurrence of CD after successful antibiotic treatment. However, there are conflicting reports. Bauer et al.(115) compared serum levels of antibodies of patients with a single episode with those of patients who suffered a recurrence. They found that: older age, comorbidity, immunocompromised state and low serum levels of antiTcdA and antiTcdB antibodies were associated with recurrence. However, serum levels of antibodies directed against cell surface antigens were not. Serum TcdBneutralizing capacity, which correlated only weakly with serum IgG antiTcdB, was not significantly associated with recurrence. In another study, found that CD recurrence was characterized by proinflammatory peripheral blood mononuclear cell (PBMC) phenotype. Used flow cytometry to define inflammatory (Th1 and Th17) and regulatory [Foxp3(+) Tregulatory (Treg)] cells present in circulating peripheral blood mononuclear cells (PBMC) from CDI patients.(116) A better understanding of intestinal microbiota and its role in CDI has opened the door to this promising therapeutic approach such as FMT that thought to resolve dysbiosis by restoring gut microbiota diversity thereby breaking the cycle of recurrent CDI.(117) 41 The recurrence of CDI, in general, the population can be a severe problem because about 25% of those suffering from CDI have a recurrence after the first course of treatment. For those patients with a recurrent episode of infection, there is a 40% chance of experiencing another recurrence and for those who have had more than 2 episodes there is a 60% chance of a further episode.(118) Global spread of the 027 (BI/NAP1/027) ribotype. C. difficile cases attributed to ribotype 027 strains had high recurrence rates (up to 36 %) and increased disease severity. Moreover, CDI recurrence was associated with excessive costs, which were mostly attributable to a significantly longer overall length of stay.(119) Prognostically unfavourable signs of complicated CDI with ileus, toxic megacolon, perforation, or sepsis (less than 5% of cases) include the absence of colonic peristalsis, suddenonset constipation, extreme leucocytosis, and high fever. Mortality resulting from CDI depends on the severity of symptoms, underlying diseases, and age. It ranges from 3% to 14%. Relapses occur in approximately 20% of cases following completion of initial treatment, typically within the first 2 to 6 weeks in patients with risk factors. The 30day attributable mortality rate was 6.9 percent.(24) What about IBD patients? CDI in IBD patients resulted in 34% recurrence, required more hospitalization and escalation of therapy, suggesting that CD resulted in increased severity of IBD disease.(31) Moreover, as in the general population, the recurrence of CDI after successful initial treatment can be a significant problem. On average, an initial recurrence can be expected in 2030% of cases and after another relapse may occur in up to 65% of patients. Risk factors associated with recurrence include older age (greater than 65), longer hospital stays (greater than 16 d), the presence of comorbidities and another course of antibiotics. Therefore, the severity of recurrent episodes of CDI cannot be underestimated. The new epidemic strain (027) has been associated with a higher rate of recurrence about 47% due to a low Ig G against toxin A due to having an inadequate antibody response. Pepin et al.(120) reviewed the outcomes of a first recurrence of CDI with the epidemic strain during the Quebec outbreak in 2005 and found 11% of these patients had at least one severe complication such as shock, colectomy, megacolon, perforation or death within 30 days. Complicated recurrence CDI was strongly associated with three factors: older age (>65), elevated white blood cell count (> 20.000) and renal failure. The longterm negative impact of CDI was also investigated by Musheret al.(121) finding 22% of patients developed recurrent diarrhoeal disease more than 90 days after the initial episode and completed the treatment, 83% of whom were toxin positive. Recently, Deshpande et al.(122) have published a systematic review and metaanalysis to evaluate current evidence on the risk factors for recurrence CDI (rCDI). Approximately, 2030% of patients with primary Clostridium difficile infection (CDI) develop recurrent CDI within 2 weeks of completion of therapy. The mechanism of recurrence remains unknown, but a variety of risk factors has been studied. Abou et al.(123) studied risk factors for recurrence, complications and mortality in Clostridium difficile infection: a systematic review. Laboratory 48 treatment with the monitorization of its levels and recurrence, but it is not useful for doing the diagnosis due to nonspecific as faecal lactoferrin. 2.6 Is the treatment the same as general population? 2.6.1 Overview Management of CDI in IBD patients with a relapse has not been optimised. We do not have specific guidelines for management of this infection in IBD patients until now. It is contradictory that, all IBD workgroups recommend the investigation of CD in stools sample in all resistant relapses to conventional treatment in outpatient and all inpatients, but there are not specific recommendations for the treatment CDI in these patients specifically. The elaboration of a specific therapeutic guideline in IBD would be important to improve the treatment of this infection in Spain and Europe. For that reason, we have to follow the indications of Microbiology General Guidelines for CDI treatment, in general, population. In 2009, the first European Society of Clinical Microbiology and Infection (ESCMID) treatment guidance document for CDI was published and has been applied widely in clinical practice. (151) Latest ESCMID Guidelines have been published in 2014. (152) In particular, after the recent development of fidaxomicin, new alternative drugs for the treatment of CDI in the USA and Europe, there has had an increasing need for an update on the comparative effectiveness of the currently available antibiotic agents in the treatment of CDI, thereby providing evidencebased recommendations on this issue. The recommendations to improve clinical guidance in the treatment of CDI, are specified for various patient groups such as nonsevere disease, severe CDI, first recurrence or risk for recurrent disease, multiple recurrences and treatment of CDI when oral administration is not possible. The options include: antibiotics, probiotics, and faecal or bacterial intestinal transplantation. The antibiotics recommended: metronidazole, vancomycin, and fidaxomicin. Faecal transplantation is recommended for multiple recurrences. We are going to revise the most important therapeutic recommendations. (See Appendices: Tables 1-10 with the most important recommendations related to treatment CDI) There is not agreement among gastroenterologists on whether combination antibiotics and corticosteroids or antibiotics alone should be given to IBD patients with CDIassociated relapses. Treatment modalities for CDI have not been examined in randomised clinical trials in the IBD population. Newer antibiotics, immunotherapy, and faecal microbiota transplantation may alter current treatment strategies. (40) It would be important we had specific protocols for the best treatment strategies in IBD patients specifically. Thus, controlled trials are needed to investigate the optimal management approach to this clinical dilemma. (153) 49 Prophylactics and hygienic measures are the same as in the general population: hand washing and cleaner hospital environments, reduce the risk of acquiring and spreading this preventable infection. In the review of this issue, we are going to start showing the limitation of the evidence about the specific treatment for CDI in IBD patients, trying to show a perspective on what could be future researches. We are going to show several gaps:  There are no controlled therapeutic trials of CDI in IBD and we need prospective multicentre ones to improve our understanding of the impact of CDI on IBD patients and define appropriate therapeutic regimens to improve patient outcome.  In IBD patients, vancomycin appears to be more efficacious than metronidazole. Randomised controlled trials are required to define clearly the appropriate management for CDI in this patients.  IBD with CDI is frequently treated with a combination of antibiotics and immunomodulators. However, this combination tends to associate with a worse outcome than antibiotic therapy alone. Prospective controlled trials are needed to optimise the management of these patients. Could we control relapses only with antibiotic treatment? One of the main points of treatments in IBD is to save corticosteroids.  Clinical studies are required to evaluate efficacy of vancomycin vs fidaxomicin.  Does CDI get worse with immunomodulators and biological treatments? Is CDI a cause or an effect of immunosuppressant and biological treatments? Metronidazole/Vancomycin Despite numerous treatment trials for CDI, dating back to 1978, the drug of choice for CDI remains controversial. In fact, Pepin et al. (154ic) said that “there are few common infectious diseases in developed countries for which the treatments used in 2006 are essentially the same as those recommended onequarter of a century ago”. However, in my opinion, the things are changing now. A clear example is the recent creation of the first faecal bank in the USA to treat recurrent and refractories CDI. In general, metronidazole and vancomycin are most used drugs used to treat CDI. A few changes have occurred in the treatment of CDI over the last 30 years. Fortunately, some recent studies have not revealed resistance to the main antibiotics for its treatment. Patients with mild or moderate diarrhoea are 50 treated with metronidazole 500 mg TID for 10 to 14 days. Patients with complicated CDI are treated with vancomycin 125 to 250 mg QID for 1014 days. Moreover, switching to vancomycin in patients who do not improve within 72 hours of initiation of treatment with metronidazole could be appropriate. Adjunctive therapy can be done with vancomycin enema 500 mg in 100 ml saline and intravenous metronidazole. Surgery with total colectomy is indicated in severe colitis with systemic symptoms. An additional challenge facing CDI treatment in IBD patients: the decreased efficacy of metronidazole and the need for oral vancomycin in hospitalized patients. As a general population, vancomycin and metronidazole appear to have similar efficacy in mild or moderate episodes but vancomycin is preferred for severe disease. Furthermore, early surgical consultation is recommended in patients with severe disease for improving outcome. (109) Metronidazole does not seem to have much resistances. In a recent study, performed from nosocomial and communityacquired CDI between 2008 and 2010 all strains studied were susceptible to metronidazole. When they comparing their results with others earlier findings from 2006 to 2007, metronidazole susceptibility did not show changes (155). Again, in 2008 it was spoken about metronidazole resistant o failure, Hu et al. (156) attempt to identify risk factors for metronidazole failure. They did not find differences in metronidazole failure rates in 1998 and 2004 to 2006 but the patients with recent cephalosporin use, CDI on admission, and transfer from another hospital were more likely to metronidazole failure. Vancomycin Therapeutically, oral vancomycin has emerged as superior treatment for IBD patients with severe disease, including those who require hospitalisation and metronidazole for mild or moderate infection. Patients with UC and nonsevere CDI have fewer readmissions and shorter lengths of stay when treated with a vancomycin compared with those treated with metronidazole alone. Patients with ulcerative colitis and CDI should be treated with vancomycin (157). In general, for CDI treatment in IBD patients, vancomycin appears to be more efficacious than metronidazole. Randomised controlled trials are required to define clearly the appropriate management for CDI in patients with IBD. Unfortunately, vancomycin capsules are very expensive. Most hospitals using the generic intravenous formulation and compounding it in water as a liquid vancomycin solution. Thus, 500 mg of vancomycin powder are reconstituted in 20 cc of water (often with flavouring to hide the bitter taste of vancomycin). Stability of the vancomycin solution in the refrigerator (4 degrees C) is at least 75 days and at least 26 days at room temperature (25 degrees C). (158) 51 Immunosuppressant treatment In IBD patients with CDI is controversial whether immunomodulators or corticosteroid therapy for IBD should be continued in patients with CDI is controversial. Normally, if the patient was treated with immunosuppressors or biologics we would not stop it. When CDI is treated in the patient was treating with immunomodulators or biological treatments these do not remove. However, limited data suggest that coadministration of immunomodulators (IM) with antibiotics (AB) result in a worse outcome than antibiotic therapy alone but we do not have studies prospective that had studied this point. BenHorin et al.(111) investigated the effects of combined therapy with antibiotics and immunomodulators in patients with IBD and CDI and found that this combination produced a worse outcome compared with antibiotic therapy alone. Yanai et al.(153) investigated the prevalent practice among North American gastroenterologists in treating relapses in IBD patients with CDI: antibiotics alone or combined antibiotics/immunomodulators. The rate of administering combined antibiotics and immunosuppressant treatments was similar for the IBD experts and the nonIBD experts. 11% of gastroenterologist withdrew maintenance azathioprine upon the diagnosis of CDI. More IBD experts stopped azathioprine treatment compared with the nonIBD experts. Overall, 65% of gastroenterologists said that they believe these patients were affected by two simultaneous processes. There is not agreement among gastroenterologists on whether the combination antibiotics and immunosuppressant treatment or antibiotics alone should be given to IBD patients with CDIassociated relapses. Controlled trials are needed to investigate the optimal management approach to this clinical situation. We need controlled trials to optimize the management of these patients. Biologic agents The use of biologic agents does not seem to increase the risk of acquisition of CDI in IBD patients, on the contrary, biologic treatment could be useful to treat these patients. Seicean et al. (29) presented a case report of worsening UC in the presence of recurrent CDI, and infliximab therapy provided favourable outcome, suggesting that infliximab treatment may be protective; however, the infliximab treatment regimen for UC patients with CDI remains to be established. 2.6.2 Treatment decision based on stratification by disease severity In the comparative studies with vancomycin and metronidazole did not stratify the patients by severity of the disease. Recently, a scoring system has been developed in the treatment of CDI. This score allows the physician to determine which patients are at highest risk for severe CDI. It was started 52 by Pepin et al. (154) who developed local recommendations, because of the devastating epidemic in Quebec caused by the new epidemic B1 strain. In January 2004, they developed local recommendations for the use of oral vancomycin: a WBC greater than 20000 cells/mm3 and a serum creatinine greater than or equal to 200 μmol/L. This recommendation was based upon a reduction of complicated CDI by 79% if vancomycin was the initial treatment compared to metronidazole (159). Zar et al. (160) conducted the first randomized, doubleblind, placebocontrolled trial comparing metronidazole and vancomycin in the treatment of CDI that stratified patients based on the severity of the disease. The authors concluded that metronidazole and vancomycin was equally effective for the treatment of mild CDI; however, vancomycin was superior for treating patients with severe CDI. Strategies for CDI management should be done according to the age of the patient, biological markers of severity and underlying comorbidities. (123). Severe CDI (152) was defined as an episode with (one or more specific signs and symptoms of) severe colitis or a complicated course of disease, with significant systemic effects and shock, resulting in ICU admission, colectomy or death. One or more of the following unfavourable prognostic factors can be present without evidence of another cause: marked leucocytosis (> 15 109/ L), decreased blood albumin (< 3 gr/L) and rise in serum creatinine level (>1.5 times the premorbid level) Miller et al. (161) created the ATLAS score for CDI, which predicts the response to therapy. They found that a combination of five clinical and laboratory variables (age, treatment with systemic antibiotics, leucocytes count, albumin and serum creatinine as a measure of renal function) measured at the time of CDI diagnosis were useful to predict treatment response. This scoring were able to predict treatment response. An early surgical consultation is key for improving outcome of patients with severe disease. (109) Surgical intervention is rarely required but in patients with severe disease or clinical deterioration, early total colectomy or loop ileostomy may be lifesaving. The outlook for patients requiring surgery remains poor. (162) When oral treatment is no possible, parenteral metronidazole is recommended, preferably combined with intracolonic or nasogastric administration of vancomycin. (152) 2.6.3 What is the best approach in the recurrences? The recurrence of disease after therapy remains a problem. The treatment includes general measures such as supportive care and infection control measures.(163) Another main goal of the therapeutic approach is treatment and the prevention onset new infections and recurrences. It should use 53 vancomycin earlier and start with new treatments such as faecal transplant in severe/recurrent episodes (152) (see Appendices: Tables 6, 7 and 8) The initial response to metronidazole and vancomycin is approximately 60%, with subsequently decreased response with subsequent relapses. Persistent alterations in the intestinal microbiota decrease natural colonization barriers and increase the risk of relapse of CDI with the same, or different strain. Several reports since 1958, amounting to over 325 cases, including one systematic review, have described high cure rates of recurrent CDI with faecal transplantation performed via retention enema, colonoscopy, or nasogastric tube. (164) Brand et al.(165) in a study in 2012 demonstrated that cure rates were sustained over longterm followup of a mean of 17 months. Patients must be treated with metronidazole or vancomycin. They usually respond to antibiotic treatment, but the therapy affects to normal bacterial flora. Thus this treatment could predispose to recurrent CDI. The colon damaged seems to be more susceptible to reinfection. Relapses occur approximately in 20% of the patients. (136) Most authors recommended, repeating the treatment with the antibiotic used in the first time, usually metronidazole, but this is not recommended in the latest guidelines. (152, 166). For more than one recurrence, it is recommended a combination of a prolonged taper of antibiotic with oral vancomycin, followed by pulsed dosing. (152) The pulsed dosing of vancomycin allows time for germination of residual spores during the days of antibiotics, vegetative form disappear when the antibiotic is given again. It is recommended: vancomycin 250 mg every 2 or 3 days for 3 week. (167, 168) 2.6.4 Role of FMT in the treatment of recurrent and refractory CDI Altered microbiota as a potential target for therapy is a growing focus on investigation because of its potential to enhance the resistance to infection and to reduce inflammatory diseases. Most extreme manipulation of the intestinal microbiota is related to faecal microbiota transplantation (FMT) from healthy donors to individuals with specific diseases. Although the concept of faecal transplantation has become more widely practiced in recent years, it has a long history. More than 2000 years ago Ge Hong used FMT to treat food poisoning and severe diarrhoea. Fabricius of Acquapendente in the 16th century described the transplantation of enteric bacteria. In recent time, the first reports about the use of FMT in our traditional medicine was done by Eiseman who treated 4 cases of pseudomembranous colitis with faecal enema obtained from a healthy donor. (2) Since the first reported use of FMT for recurrent CDI in 1958, systematic reviews of case series and case report have 54 shown its effectiveness with highresolution rates compared to standard antibiotic treatment. FMT is administrated by nasojejunal or colonoscopy for the treatment of recurrent CDI. Restoration of intestinal flora and restoration of colonization resistance are the mechanism responsible for treating in these recurrent episodes of CDI Faecal microbiota transplantation (FMT) is considered a successful therapy for recurrent and refractory Clostridium difficile infection (CDI) based on recent clinical trials. FMT restores essential components of the microflora that could reverse the inflammatory processes observed in IBD so it may be beneficial for the treatment of ulcerative colitis and Crohn's disease, particularly those with concurrent CDI or with pouchitis (2, 26, 164). However, there are to perform more studies to evaluate its useful in IBD patients. (169) There are studies in children to treat recurrent Clostridium difficile infection via nasogastric tube or colonoscopy without adverse events during short or longterm followup, and all of the patients had clinical improvement of gastrointestinal symptoms.(170) Hourigan et al. (38) studied CD eradication and microbiome changes in children with and without IBD after treatment with TMT. The authors concluded that FMT was effective for CDI in children with and without IBD. In those with IBD, bacterial diversity returns to preFMT baseline 6 months after treatment, suggesting IBD hostrelated mechanisms modify faecal microbiome diversity. The longterm consequences of FMT with regards to infection, cancer, autoimmune and metabolic diseases, are not known.(26) Recent research about commensal microbes and their impact on the host will lead to the development of new probiotic agents.(171) The ultimate goal is the development of powerful probiotic regimens that can replace FMT. Currently, FMT should only be given in a strict experimental setting for other conditions than CDI.(28) Some questions remain unanswered: the optimal protocol for donor faeces administration (naso duodenal tube, enema or colonoscopy) is unknown. Furthermore, the efficacy of this modality in severe CDI, as well as in special populations such as patients with inflammatory bowel disease, cirrhosis, and immune compromised states. Further studies are required, however, to determine the optimal protocol for donor faeces administration. (UEG: Vienna, October 2014) It is a safe and effective treatment for recurrent CDI and is now recommended in European treatment guidelines. Healthy microbiota harvested from a donated stool sample is transplanted into the intestine by colonoscopy or enemawhere it helps to restore the normal composition of the gut flora and overcome the harmful consequences of CDI. It eradicates recurrent infection in around 90% of patients. 55 2.6.5 What is coming up: future treatments In a briefly way, we are going to revise some of most new treatments for CDI although is not our main goal. In the treatment of this infection as important as treat the first episode is to avoid the recurrences. Several novel therapies are currently under study: new antimicrobial agents have a good activity against CD without altering normal gut flora, CD toxinabsorbing compounds, and antibodies and vaccines against CD toxin (immunotherapy) and faecal microbiota transplantation may alter current treatment strategies Fidaxomicin Patients responded to oral vancomycin or metronidazole; however, the rate of recurrences is high. For that reason, it has investigated new therapies to treat this infection. Fidaxomicin, firstinclass macrocyclic antibiotic has minimal intestinal absorption, high faecal concentration, and cause less disruption of anaerobic microbiota during treatment of CDI than vancomycin and moreover, it has activity against many vancomycinresistant enterococci. (172) Recommended dose is 200 mg every 12 hours for 10 days. In Spain, we already have it but the main problem is its high cost. In two doubleblind, noninferiority, randomised controlled trial, comparing the efficacy and safety of fidaxomicin with vancomycin in the treatment of CDI. The authors demonstrated fewer recurrences and higher rates of sustained clinical cures compared with the current gold standard, vancomycin. Thus, fidaxomicin can be an alternative treatment for CDI, with similar efficacy and safety to vancomycin. (173) This drug is an antibiotic therapy for CDI and must be considered as a firstline agent for patients with risk factors known to have a relapse and severe infection. (174) A study in 2011 assessed the efficacy of fidaxomicin versus vancomycin as therapy for CDI in individuals was taking concomitant antibiotics. (175) Due to low recurrence ratio and safety, it could be one of the first lines of CDI treatment in patients with cancer. (176) Recently, Chilton et al. (177) found that pulsed or tapered regimens of fidaxomicin had the same efficacy of vancomycin but reduced the risk of recurrent CDI compared with vancomycin. Moreover, pulsed or tapered regimens of fidaxomicin allowed greater bifidobacteria recovery than the extended (20 days) regimen. Consequently, this may enhance suppression of C. difficile while allowing microbiota recovery; clinical studies are required to ascertain the potential of this approach in reducing recurrent CDI.(178) 56 Probiotics Probiotics are used by everybody, but we do not have solid scientific evidence. Could probiotics have a protector role? Recently, Ramakrishnan et al.(179) performed a study in India where there is an overuse of antibiotics to demonstrate an increase of CDI. However, they found that the incidence of CDI in India (1.67%) was no different from reported in the USA (1.6%) using similar techniques of detection (polymerase chain reaction test). They offer a possible explanation for this paradox. It is likely that a diet rich in fibre, yogurt, and possibly turmeric may have a protective role in decreasing the incidence of CDIs in India Most gastrointestinal disease specialists recognize a role for probiotics and have used it as part of their therapeutic options. Williams et al.(180) in 2010, demonstrated that all physicians believed probiotics were safe for most patients, and 98% responded that probiotics had a role in treating gastrointestinal illnesses or symptoms, and 93% of physicians had patients taking probiotics most often for irritable bowel syndrome. Differences of pathogen clearance and microbiome alteration during treatment of CDI appear to explain treatment outcome. The hypothesis that probiotic microbes (Lactobacilli) could help to prevent the CDI is supported by the observation of persistence of Lactobacilli during and after treatment of CDI. (181) In conclusion: the use of conventional probiotics remains controversial, and most studies are of low quality. No overall recommendations can be provided by the moment. Active and passive vaccination There are good data from animal experiments. Current research on vaccination is at the stage of phase III clinical trials. It has to investigate which population sample would be more effective to give the vaccine. There are studies on going. SMT19969 It is a new antimicrobial agent against 162 strains from 35 less frequently recovered intestinal Clostridium species. Currently under development for the treatment of CD, it has been reported the results from a phase I study (182) comparing in vitro activities of SMT19969 and its implications for treating Clostridium difficile recurrence. SMT might have less impact on normal gut microbiota than other CDI treatments. (183) 57 LFF571 Novel thiopeptide antibacterial that shows in vitro potency against CD comparable or greater than other clinically used antibiotics. It was compared the pharmacokinetics of LFF571 and vancomycin in patients with moderate CDI as part of an early efficacy study, and the results seem consistent demonstrating the retention of LFF571 in the lumen of the gastrointestinal tract. (184) Amixicile Another novel treatment that shows efficacy in the treatment of CDI and recurrences, but still in a mouse models. It is a watersoluble derivative of nitazoxanide (NTZ), an antiparasitic therapeutic that also shows efficacy against CDI in humans. 2.7 General recommendations for the prevention and control of CDI In developed countries, Clostridium difficile is the most common cause of healthcareacquired infection. CDI is a frequent cause of morbidity and even death. It also produces huge economic costs, because of infected patients with CDI stay in the hospital for some additional 13 weeks more than normal. Regarding cost and productivity, C. difficile is a major burden on our health care system. The key points for the prevention and control of CDI: 1Control of risk factors. When we use antibiotics is important an appropriate antimicrobial stewardship. If was possible, we would have to stop antibiotic treatment in patients with CDI. In most cases, we cannot eliminate the antibiotic treatment so we should decrease the use of broad spectrum antibiotics for narrower spectrum ones. (63, 65, 67, 69, 185) Another factor is malnutrition of patients which is a predisposing factor in a long term care facility. (70) 2Early diagnosis (high diagnostic suspicion). Axelrad et al.(113) studied the use of nursing admission (protocol) workflow to increase the rate of CDI testing. The intervention increased CDI testing for IBD inpatients with a relapse. We have to suspect in outpatient with a relapseresistant to conventional treatment or with a relapse and risk factors for the infection. Moreover, in all hospitalized due to a relapse or worsen during the hospitalization. 3Hygiene measures and prophylaxis CDI, to prevent spread by the medical staff to other patients and contamination with spores the hospital environment and surfaces and to avoid horizontal transmission. Patients usually acquire the organism from the hospital, no from their flora. Unfortunately, the spores 64 65 Chapter 3 66 67 4. Chapter 3: Results From June 2007 to June 2015, we analysed 131 CDI episodes in IBD patients with a relapse (case group) comparing with IBD patients with a relapse but without infection (control group). Moreover, we studied the recurrent CDI episodes. We are going to show you the results of our study with the following outline:  Firstly, we would like to give you a general vision of the distribution of CDI (positive results); a comparison of positive results in IBD patients with positive results in nonIBD patients in the same period of time and the proportion between request samples within the total sample and final positive results.  Secondly, we are going to see how long it takes to diagnose these patients in our hospital.  Thirdly, we are going to explain the results of casecontrol study including risk factors and outcome.  And finally, we are going to comment our results in the study of recurrent episodes. 4.1 Distribution of CDI episodes In our tertiary centre, we do not have found an increase in the number of CDI episodes in both, nonIBD and IBD patients during the period of the study. Moreover, the number of positives CDI episodes tends to maintain or decrease but in no case has increased last 8 years. We realized that proportion of positive results was low compared with the number of request samples. 68 4.1.1 Positive episodes distribution during the period of our study Distribution of positive samples from June 2007 to June 2015. It can be seen as the number of positives episodes have been decreasing during the period of the study. Thus, from January to June 2015, we do not have had any case. (Figure 1) Figure 1. Distribution of positive samples from June 2007 to June 2015. 16 28 25 17 14 12 6 8 0 0 5 10 15 20 25 30 IBD 69 4.1.2 Positive episodes distribution comparing with general population Positive episodes distribution in IBD patients compared with positive episodes in nonIBD population from June 2007 to June 2015. The distribution of CDI in general population has not been increasing during the last 6 years, but at the same time it has been maintained in similar proportions in contrast to IBD population. (Figure 2) Figure 2. Positive episodes distribution in IBD patients compared with positive episodes in nonIBD population from June 2007 to June 2015. 92 139 161 102 87 51 55 85 35 16 28 25 17 14 12 680 0 20 40 60 80 100 120 140 160 180 2007 Jun_Dec 2008 2009 2010 2011 2012 2013 2014 2015 Jan_Jun No IBD IBD 70 4.1.3 Total requested samples in IBD patients compared with positive final results Total requested samples in IBD patients compared with positive final results. The number of requested samples was higher than the number of positives results in a very striking way. We found a low proportion of positive results compared with a large number of requests. (Figure 3) Figure 3: Total requested samples in IBD patients compared with positive final results. 54 117 149 113 94 122 119 127 34 16 28 25 17 14 12 680 0 20 40 60 80 100 120 140 160 2007 Jun_Dec 2008 2009 2010 2011 2012 2013 2014 2015 Jan_Jun Total samples Positive samples 71 4.2 Time it took to diagnose our patients The time it takes for the positive results to come out from Microbiology department was 4.22±6.281 days, the time it takes from positive result release to doctor´s appointment was 7.59±6.223 days and time it takes from first doctor´s appointment to result delivery to the patient was 15.58±8.265 days. In our department, CDI took an average of 14 days to diagnose, but the positive result was coming out from the Microbiology Department in an average time of 2 days. Therefore, there is an untapped space of about 1012 days in which it would be possible to know the samples results. (Table 1) Table 1: Days to diagnose CDI in outpatients. Time it takes for the positive result to come out (Microbiology Department) Time it takes from positive result release to doctor´s appointment Time it takes from first doctor´s appointment to results delivery to patient Mean (days) Median Mode Minimummaximum 4.22±6.281 2.00 2 153 7.59±6.223 7.00 7 030 15.58±8.265 14.00 14 442 72 Figure 4: Days that it takes for results come out from the Microbiology Department. Figure 5: Distribution of days since the positive result was available until IBD patients visited the doctor. Figure 6: Days since first doctor´s appointment until the patients go back again to know the results. 73 4.3 Case-control study From June 2007 to June 2015, we analysed 131 Clostridium difficile infection (CDI) episodes in IBD patients with a relapse (case group) compared with IBD patient with a relapse but without CDI (control group). 4.3.1 General characteristics of episodes The results were the following in cases and controls respectively (see table below). We did not find significant differences between both groups in mean age and gender. CDI episodes presented in less than 10% in patients >65 years old. In AutumnWinter occurred: 28% (37) and 18% (19) of episodes. There was a smoking history: 20% (27) and 18% (19); in case group CD 67% (18) (OR 2.47; CI 95% 1.633.74, p=0.00) and in control group CD 89% (17) (OR 1.60; CI 95% 1.262.04, p=0.00). We did not have CDI episodes in patients with previous colectomy (neither in the control group). Average ages were predominant in both groups at IBD diagnosis: ≤16: 6% (8) and 11% (12); 1740: 71% (93) and 65% (70); >40: 23% (30) and 22% (24). Table. General characteristics of episodes Case Controls p value Mean age 38.11±14.759 38.46±15.547 NS >65 10 (8%) 6 (6%) NS Gender Female Male 76 (56%) 55 (42%) 57 (53%) 50 (47%) NS Season AutumnWinter SpringSummer 37 (28%) 94 (72%) 19 (18%) 88 (82%) p=0.05 Smoking history UC CD 27 (20%) 9 (33%) 18 (67%) p=0.00 19 (17.7%) 2 (11%) 17 (89%) p=0.00 NS Previous surgery (colectomy) 11 (8.3%) 17 (15.8%) NS 80 CD and UC episodes without CDI had more relapses the first year and after CD had more relapses and the number of UC episodes stabilized. Figure. Controls (CD and UC) 81 The behavior of UC and CD with and without CDI was different: CDI makes the behavior of ulcerative colitis similar to the behavior of Crohn´s disease without CDI. Moreover, UC with CDI seems to have a different behavior as compared with UC without infection. UC with the infection has more probability of relapse and earlier than UC without infection, where the evolution only depends on its natural evolution. In contrast, in CD with the infection the relapses were less frequent when compared with CD without infection, in which the relapse depends on the natural evolution of the disease, without an external element triggering the relapse. (See figures) UC episodes with CDI (cases), had more probability of relapse the first 7 years, with a different behavior compared with CD. In control group: probability of relapse without infection in UC and CD from IBD diagnosis (years) 82 UC with CDI had more likely to relapse compared with UC without infection. Figure. UC probability of relapse with/without infection from IBD diagnosis (years) Relapse in CD episodes was earlier without infection (when the relapse was by IBD per se). When the relapse was because of CDI the behavior was better (with an external cause). Figure. CD probability of relapse with/without infection 83 Samples were requested as outpatient in more than 70% of episodes in cases and controls: 78% (103) and 75% (80) respectively. When we analyzed separately UC and CD in case and control group we found in cases 69% (71) UC and in controls 54% (43) CD (p=0.01). Episodes with hospitalizations in case and control group were similar: 22% (29) and 23% (25) respectively. Hospitalization in controls was higher in CD 88% (22) compared with UC 12% (3) (OR 1.64; CI 95% 1.282.10, p=0.00) but in cases was similar. Thus, CDI. Average stay in cases and controls were 12.03±9.697 and 14.22±13.497 respectively, without differences. Case group Control group CD 32 43 UC 71 37 0 20 40 60 80 100 120 Outpatients NS 103 (79%) 80 (75%) p=0.01 84 Episodes at IBD diagnosis and relapse with/without CDI occurred at the same time comparing case and control group: 13% (17) and 7% (7) (p=0.1). 13% of cases had an IBD diagnosis and CDI at the same time, without differences between UC and CD (see figure below). IBD diagnosis and relapse with/without CDI at the same time and hospitalization in cases and controls were: 4% (5) and 6% (6) respectively (see figure below) Case group Control group CD 15 22 UC 14 3 0 5 10 15 20 25 30 35 Hospitalization NS 29 (22%) 25 (23%) p=0.00 Case group Control group CD 9 5 UC 8 2 0 2 4 6 8 10 12 14 16 18 IBD diagnosis at the same time p=0.1 85 The severity of episodes in case group was more frequent mildmoderate: 32% were mild ones. More than 50% had moderate severity, and only 5% of episodes were severe. There were not differences between UC and CD. We did not find differences compared with the control group. When applied criteria of severe CDI, we found most episodes were not severe ones. Severity and hospitalization in case group: mild; 7% (2), moderate; 72% (21), severe; 21% (6) but without differences with control group. Case group Control group CD 2 5 UC 3 1 0 1 2 3 4 5 6 7 Hospitalization when IBD diagnosis occurred at the same time NS Mild Moderate Severe CD 13 31 2 UC 29 52 4 0 10 20 30 40 50 60 70 80 90 Severity of episodes N 32% 63% 5% 86 Comorbidity in episodes: CDI patients presented more comorbidity than control group: 38 (29%) and 17 (16%) (OR 1.36; CI 95% p=0.01). Numbers of comorbidities in cases and control: 0; 71% (93) and 84% (90), 1; 24% (31) and 34% (16), >1; 7 (5%) and 1 (0.9%) (p=0.03). There were no differences between UC and CD in cases and controls. (See figure below). In cases group: comorbidity and severity in cases group: mild 29% (12), moderate 31% (26), severe 0% (0) (there is not comorbidity in severe episodes). Number of comorbidities and severity: 1comorbitiy and mild episode 24% (10), moderate 25% (21) and severe 0% (0) and>1 comorbidity and mild 5% (2), moderate 6% (5) severe 0% (0) (no differences with control group) Hospitalization and severity Mild 2 Moderate 21 Severe 6 0 5 10 15 20 25 Hospitalization and severity p=0.00 87 We found a higher proportion of chronic obstructive pulmonary disease (COPD), heart disease and diabetes in cases but without differences with controls. Comorbidity No comorbidity 1 comorbidity >1 comorbidity Case group 38 93 31 7 Control group 17 90 16 1 0 10 20 30 40 50 60 70 80 90 100 Comorbidities p=0.03 p=0.01 29% 16% Cases Control CasesControl CasesControl Cases Control CD 17 9 29 57 13 9 4 0 UC 21 8 64 33 18 7 3 1 0 10 20 30 40 50 60 70 80 90 100 Comorbidities comparing UC and CD Comorbidity NS No comorbidities 1 comorbidity >1 comorbidity NS 88 Ca Co Ca Co Ca Co Ca Co Ca Co Ca Co Ca Co Ca Co CD 5 3 5 3 1 0 3 0 5 2 3 0 0 0 1 0 UC 5 4 9 2 0 0 0 1 5 1 3 0 1 0 2 2 0 2 4 6 8 10 12 14 16 Comorbidities Heart disease COPD Hemodialysis Chronic Renal failure Diabetes Autoimmune disorders HIV Neoplasia NS 89 Hospitalization in patients with comorbidities had a tendency to be higher in case group but without differences between both groups. 4.3.2 Laboratory parameters We have not found statistic differences between cases and controls in inflammatory parameters such as CRP, ESR, ferritin, platelets levels and faecal calprotectin. However, calprotectin levels have a tendency to be higher in cases (p=0.06) (but we had a small samples sizes because we did not have samples in all episodes). We have not found differences in albumin levels between cases and controls. We have not found differences in haemoglobin, ferritin and Fe levels between cases and controls. Creatinine levels were normal in both groups without differences. (Neither if we compare ulcerative colitis and Crohn´s disease between them in both groups) Cases Controls p value Faecal calprotectin Mean Standard deviation N=34 992.47 1558.400 N=26 464.96 396.558 p=0.06 CRP Mean Standard deviation N=83 2.79 4.77 N=75 3.00 5.09 NS Hospitalization and comorbidity Cases 7 Controls 3 0 1 2 3 4 5 6 7 8 Hospitalization and comorbidity 5% 3% 96 Oral mesalamine Rectal mesalamine Immunosuppress ors Biologics Apheresis Cases 101 29 51 11 13 Controls 67 16 54 20 5 0 20 40 60 80 100 120 Treatments at the moment of episodes p=0.00 p=0.00 NS NS NS Azathioprine Mercaptopurine Methotrexate Cases 36 12 3 Controls 46 8 2 0 5 10 15 20 25 30 35 40 45 50 Immunosuppressant treatment p=0.01 NS NS 28% 43% 9% 8% 2% 2% 97 Figure. Combined treatment: 0, 1 (immunosuppressant or biological treatment or apheresis), 2 (immunosuppressant y/o biological treatment y/o apheresis), 3 (immunosuppressant, biological and apheresis treatment) Infliximab Adalimumab Apheresis Cases 4 8 13 Controls 6 14 5 0 2 4 6 8 10 12 14 16 Biological treatment and apheresis NS NS NS 3% 6% 6% 13% 10% 5% 0 1 2 3 Cases 70 46 15 0 Controls 42 51 12 2 0 10 20 30 40 50 60 70 80 Combined treatment NS 53% 39% 33% 48% 11% 2% 98 4.3.4 Risk factors Antibiotics 3 months before comparing cases and controls: 16% (21) and 6% (6) (OR 1.49; CI 95% 1.171.89, p=0.01). In control group: UC y CD 0% y 100% respectively (p=0.04). PPIs 3 months before: 63% (82) and 45% (48) (OR 1.39; CI 1.081.77, p=0.00). Hospitalization 3 months before: 7% (9) and 9% (10). Surgery 3 months before: 3% (4) and 7% (8). Figure. Distribution of main risk factors at the moment of IBD relapse with/without CDI (case and control group). We found in the group of hospitalized patients PPIs (OR 2.63; CI 95% 1.285.39, p=0.00) and antibiotics 3 months before episodes (OR 1.66; CI 95% 1.062.58, p=0.05) were significantly more frequent in CDI patients comparing cases and controls. Antibiotics PPIs Hospitalization Surgery Case group 21 82 9 4 Control group 6 48 10 8 0 10 20 30 40 50 60 70 80 90 Risk factors 3 months before p=0.01 p=0.00 NS NS 99 Figure. Distribution of main risk factors in UC and CD in case group. Figure. Distribution of main risk factors in UC and CD in controls group. Antibiotics PPIs Hospitalization Surgery CD 10 30 5 3 UC 11 52 4 1 0 10 20 30 40 50 60 70 80 90 Cases group (UC and CD) Antibiotics PPIs Hospitalization Surgery CD 6 30 8 7 UC 0 18 2 1 0 10 20 30 40 50 60 Control group (UC and CD) p=0.00 100 Figure. Age >65 Figure. Comorbidity comparing cases and controls Case group Control group CD 3 2 UC 7 4 0 2 4 6 8 10 12 Age >65 NS Case group Control group CD 17 9 UC 21 8 0 5 10 15 20 25 30 35 40 Comorbidity p=0.01 101 Figure. Numbers of comorbidities 0 1 >1 0 20 40 60 80 100 0 1 >1 Controls 90 16 1 Cases 93 31 7 Numbers of comorbidities p=0.03 102 4.3.5 Independent risk factors for CDI episodes We performed the multivariate analysis with variables with statistical signification or p<0.2 in univariate analysis. Risk profile of IBD patients with a relapse for CDI (independent risk factors in multivariate analysis):  Patients with ulcerative colitis.  Medical history of antibiotics 3 months before episodes.  IBD diagnosis and CDI at the same time.  Comorbidity. (PPIs 3 months before episodes, were a risk factor in univariate analysis) 103 4.3.6 Outcome We did not find differences in the outcome between cases and controls: therapeutic escalation 6 months after episodes: 37% (48) and 35% (37); hospitalization 6 months after episodes: 12% (16) and 7% (7); surgery 1 year after episodes: 4% (5) and 3% (3); complications: 2% (2) and death 0.7% (1). We had 2 episodes with complications and 1 death. Therapeutic escalation 6 months after Hospitalizatio n 6 months after Surgery 1 year after Complications Exitus Cases 48 16 5 2 1 Controls 37 7 3 0 0 0 10 20 30 40 50 60 Outcome 35% 37% NS 7% 12% 3% 4% 2% 0.7% 104 Therapeutic escalation 6 months after Hospitalization 6 months after Surgery 1 year after Complications Exitus CD 16 6 4 1 0 UC 32 10 1 1 1 0 10 20 30 40 50 60 Cases: UC and CD NS Therapeutic escalation 6 months after Hospitalization 6 months after Surgery 1 year after Complications Exitus CD 26 5 3 0 0 UC 11 2 0 0 0 0 5 10 15 20 25 30 35 40 Controls: UC and CD NS 105 4.3.7 CDI treatments We treated 97% of episodes (first and recurrent ones) with oral metronidazole as the first choice. In general, we did not use oral vancomycin, and we used spiraxin in some first episode. We did not use probiotics except in one recurrent episode, and we did not use spiraxin as coadjuvant treatment. Global (n=131) Ulcerative colitis (n=85) Crohn´s disease (n=46) p Metronidazole (oral) First episode (n=107) Recurrent episodes (n=24) 127 (97%) 104 (97%) 23 (96%) 83 (98%) 44 (96%) NS Vancomycin (oral) First episode (n=107) Recurrent episodes (n=24) 2 (2%) 1 (0.9%) 1 (4 %) 1 (1%) 1 (0.2%) Metronidazole (IV) First episode (n=107) Recurrent episodes (n=24) 1 (0.7%) 1 (0.9%) 0 1 (1 %) 0 Spiraxin First episode (n=107) Recurrent episodes (n=24) 4 (3%) 4 (4%) 0 2/85 (2.3%) 2/46 (4.3%) VSL 3 1/131 (0.7%) 1/85 (1%) 0 112 PPIs 3 months before 9 (90%) 3 (43%) P=0.03 Hospitalization 3 months before 0 0 Surgery 3 months before 1 (10%) 0 Cases had a tendency for therapeutic escalation 6 months after infection in contrast to the control group. 40% of episodes in CDI group needed hospitalization 6 months after episodes while in the control group did not. Moreover, we found a 10% of surgeries in cases compared with 0% in controls. It has seemed a tendency to the escalation of treatment, hospitalization, surgery, complications and mortality in CDI group in contrast with no episodes in the control group. All complications and mortality occurred in CDI episodes. It would be necessary to increase the number of patients for improving the statistic power of this study. Table. Outcome Cases Controls p value Escalation therapeutic 6 months after Hospitalization 6 months after Surgery 1 year after 3 (30%) (1/3) 4 (40%) 1(10%) 0% 0% 0% NS NS NS Complications CDI complications Exitus 1 (10%) 0% 1 (10%) 0% 0% 0% NS Laboratory parameters 113 Cases Controls p value Calprotectin levels <200 200-500 >500 N=3 1 (10%) 2 (20%) 0 No ESR CRP Albumin Platelets Hemoglobin Ferritin Fe 40.40 1.5633 3.36 327,333.33 11.53 96.80 49.20 30.67 1.4833 3.400 346,500 12.55 105.73 51.50 NS We had a small sample size of episodes with laboratory parameter, but we did not find differences between both groups. 114 4.4 Recurrent episodes of CDI in IBD patients So far, we have analysed from June 2007 to June 2015, 131 CDI episodes in IBD patients with a relapse (cases) compared with IBD patient with a relapse but without infection (controls). We found 24 recurrent episodes, and we are going to analyse their characteristics in this section. First of all, we are going to show you a general perspective of them. Secondly, we are going to highlight their characteristics in general and specifically comparing UC and CD patients. 4.4.1 General picture of recurrent episodes in CDI patients We found 24 (18%) recurrent CDI episodes. The distribution of recurrent CDI episodes from June 2007 to June 2015 showed a tendency to decrease in IBD patients (similar tendency to positive episodes in general). They were produced in UC patients more than in CD patients and more than 50% > 8 weeks after the previous episode. Last two years, there were not recurrent episodes in CD patients and the last year not recurrent episodes in both. Figure. Distribution of recurrent CDI episodes from June 2007 to June 2015 115 Figure. Distribution of IBD in recurrent episodes In the analysis of recurrent episodes, the first recurrence was the most frequent, about 65% and more than 50% occurred >8 weeks after the previous episode. The first recurrence is more frequent than the second and the third one. However, the second recurrence was the earliest; it occurred <8 weeks after the previous one. In second and third recurrences, there were not CD episodes. 20 (83%) 4 (17%) Recurrent episodes Ulcerative colitis Crohn´s disease n=107 (82%) First recurrence 13% Second recurrence 3% Third recurrence 2% Total episodes One episode First recurrence Second recurrence Third recurrence Global recurrence n=24 (18 %) 116 Figure. Distribution of recurrent episodes: first, second and third recurrences. Table. The time it took for recurrent CDI episodes to appear in the patients. Cases n (%) Recurrence time (months) Recurrence time (> or <8 weeks) Total CDI episodes 131 Recurrent CDI episodes First recurrence Second recurrence Third recurrence 24 (18%) 17 (71%) 4 (17%) 3 (13%) 17.57±21.964 9.00±13.663 21.33±24.132 > 8 weeks 14 (58%) <8 weeks 10 (42%) >8 weeks 11 (65%) >8 weeks 1 (25%) >8 weeks 2 (67%) Figure. Time recurrence takes to appear (> or < 8 weeks) 58% 65% 25% 67% 117 Table. Recurrence time Recurrence time (months) First recurrence CD UC Second recurrence CD UC Third recurrence CD UC 17.57±21.964 27.00±21.055 15.58±22.177 9.00±13.663 No recurrences 9.00±13.663 21.33±24.132 No recurrences 21.33±24.132 Figure. Distribution of UC and CD in the first recurrence 118 Figure. Probability of a first recurrence (months). Figure. Probability of a second recurrence (months). Figure. Probability of a third recurrence (months). 119 4.4.2 Characteristics of recurrent episodes and comparison of UC and CD We analyzed 24 recurrent CDI episodes during the period of our study. 4 episodes (17%) occurred in CD patients and 20 episodes (83%) in UC patients (p=0.03). Figure. Distribution of IBD in recurrent episodes We studied 24 recurrent episodes in which we found four episodes (17%) occurred in CD patients and 20 episodes (83%) in UC patients (p=0.03). IBD was diagnosed in middleaged patients. The patients have a mean age of 39 at the moment of episodes, but 13% of recurrent episodes occurred in patients older than 65 and ulcerative colitis. In our study, we did not find patients >65 with a recurrent episode and Crohn´s disease. Women and men had a similar distribution. The recurrent CDI infections appeared in AutumnWinter as well as in SpringSummer. There is a smoking history in 13% of recurrent episodes and it is more frequent in the CD group (p=0.01). We found 21% of episodes with more than one comorbidity without differences between UC and CD. Recurrent episodes did not occur in patients with previous colectomy. 20 (83%) 4 (17%) Recurrent episodes Ulcerative colitis Crohn´s disease 120 Table. General characteristics of patients with recurrent episodes Recurrent episodes (n=24) Ulcerative colitis (n=20) Crohn´s disease (n=4) p value Mean age±standard deviation 39.17+/16.343 40.65+/17.070 31.75+/10.689 NS Age >65 3 (13%) 3 (15%) 0% NS Gender Male Female 12 (50%) 12 (50%) 9 (45%) 11 (55%) 3 (75%) 1 (25%) NS Seasonality Autumn and Winter Spring and Summer 10 (42%) 14 (58%) 9 (45%) 11 (55%) 1 (25%) 3 (75%) NS Smoking history 3 (13%) 1 (5%) 2 (50%) P=0.01 Comorbidity (≥1) 5 (21%) 3 (15%) 2 (50%) NS Surgery (colectomy) 0% 0% 0% NS Mean age at IBD diagnosis 33.21+/17.118 35+/17.859 24.25+/9.912 NS We found colonic involvement in 75% of episodes in Crohn´s disease. Left and extensive colitis localization are predominant in ulcerative colitis (35% and 40% respectively). Moreover, 50% of episodes in Crohn´s disease occurred in a disease with perianal localization too. We have found recurrent episodes with all behaviors without a prominent one. 121 Table. Disease localization and behavior in recurrent episodes Disease localization in recurrent episodes (n=24) Crohn´s disease (n=4) L1 L2 L3 L4 Perianal 1 (25%) 1 (25%) 2 (50%) 0 (0%) 2 (50%) Behaviour in recurrent episodes (n=24) Crohn´s disease (n=4) B1 1 (25%) B2 1 (25%) B3 1 (25%) Plastron 1 (25%) Abscess 1 (25%) Table. Disease localization in recurrent episodes Disease localization in recurrent episodes (n=24) Ulcerative colitis (n=20) E1 (proctitis) 5 (25%) E2 (left-sided colitis) 7 (35%) E3 (Extent colitis) 8 (40%) 88% of recurrent episodes happened in outpatients without differences between UC and CD. These recurrent episodes need hospitalization in 16% of episodes with more in the CD group (p=0.05) but with a mean stay of 12 days without differences between two groups. Most episodes (79%) are moderate episodes without differences between CD and UC. 128 Treatment of CDI recurrent episodes 95% of recurrent episodes (first, second and third) were treated in the same way, with oral metronidazole. We used oral vancomycin in less than 5% of recurrent episodes. Moreover, we did not use spiraxin or fidaxomicin. We used probiotics in less than 5% of episodes. 88% of recurrent episodes were treated with corticosteroids: 90% with prednisone, mean doses 29 mg (with differences between UC and CD, we used higher doses in CD (p=0.00) 129 Recurrent episodes (n=24) Ulcerative colitis (n=20) Crohn´s disease (n=4) p value Oral metronidazole Oral vancomycin IV metronidazole Spiraxin VSL3 Fidaxomicin 23 (96%) 1 (4%) 0% 0% 1 (4%) No 19(95%) 1(5%) 1(5%) 4(100%) 0% 0% NS NS Corticosteroids Prednisone Beclomethasone Mean doses (mg) 21(88%) 16 (67%) 5 (21%) 29.25±17.417 17(85%) 12 (60%) 5 (25%) 25.31+/17.173 4 (100%) 4 (100%) 0 45+/5.774 NS p=0.00 Outcome in recurrent episodes We found in the study of recurrent episodes that in 38% of episodes, therapeutic escalation was necessary 6 months after. Hospitalization was necessary 6 months after 17% of episodes. In both cases, there were no differences between CD and UC. We did not find colectomies 1 year after of episodes. Our patients did not have complications, neither mortality, because of CDI per se. Recurrent episodes (n=24) Ulcerative colitis (n=20) Crohn´s disease (n=4) p Therapeutic escalation 6 months after 9 (38%) 8 (40%) 1 (25%) NS Hospitalization 6 months after 4 (17%) 3 (15%) 1 (25%) NS Surgery 1 year after (colectomy) 0% 0% 0% Complications 0% 0% 0% Mortality 0% 0% 0% 130 131 Chapter 4 132 133 5. Chapter 4: Discussion of results In order to facilitate reading, this section will follow a similar structure as the results section before. In particular, we have divided this discussion into the following parts: epidemiological aspects, general characteristics of IBD, risk factors for acquisition of CD in IBD, outcome, recurrent CDI and CDI treatment. Finally, we will conclude by pointing out the major contributions and several limitations of our dissertation, as well as our proposals for future research. Epidemiological aspects The incidence of CDI is increasing worldwide, and it has become a relevant health concern for the international community. Its treatment is a challenge in the USA and the UK, where it has produced multiple and severe outbreaks. It can be a serious disease that can compromise the patients’ lives. Proof of all this is the recent creation of the first faecal bank in the USA for the treatment of more severe and recurrent CDI episodes. In Spain, the overall situation with respect of CDI is not wellknown at the moment. There are a few epidemiological studies on the prevalence of CDI in the general population, and the available data indicate that CDI incidence is within the range of surrounding countries but not increasing.(188) IBD patients have a higher incidence of CD in comparison with the general population. (31, 32) IBD is one of the strongest comorbidities associated with the possibility of CDI.(30) The prevalence of CDI in IBD patients in Spain is not well characterized and, only recently, one study published about Spanish IBD patients, just evaluated specific risk factors.(189) Outbreaks have not been reported in Spanish IBD patients in contrast with the general population, but with very few cases compared with other European cities and North America. (188, 190) In our tertiary teaching center, we have not found an increase in the number of positive episodes in both, general population and IBD patients, during the period of the study from June 2007 to June 2015. Moreover, the number of positives CDI episodes exhibited a constant o decreasing tend, never increasing in the last 8 years. Thus, the situation in IBD patients in our area does not seem to be the same compared with the general population. There has been an increase in awareness about the existence of CDI and its influence on inflammatory bowel disease patients. In the USA, administrative database studies have suggested that the incidence of CDI on IBD, as in the general population, was increasing, but their design makes it hard to distinguish the real scope of the study with a consequent detection bias. (43) There is an apparent steady increase in CDI incidence complicated IBD in the last 10 years, specifically in UC and colonic Crohn´s disease.(39, 43)This increased incidence is more evident in large 134 studies as compared with smaller ones, but it is very hard to assess because of the differences between the used diagnosis methods.(42) We have found that the proportion of positive results was low when compared with the number of requested samples. Several reasons could explain it: one explanation may be that in our centre, physicians requested control samples for most of the patients after their treatment. The latest guidelines to manage CDI (152) in the general population (there is not specific guidelines about management of CDI in IBD patients) recommend that after treatment samples are requested if the patient did not have a good evolution or the patient did not respond to the treatment or reinfection is suspected. If the patient improves after the treatment, it is not demonstrated that a routine request is necessary to confirm the response to treatment. Furthermore, one request sample is enough for CDI diagnosis. In addition, in most cases, we asked for an early CDI study in all the relapses. We should not routine request a study of stools in all IBD relapses from the start of the process. We should request it when the patients have risk factors for the infection, do not respond to the optimization of basal treatment, corticosteroids treatment, intensification of treatment and in hospitalized patients. (1) In our Gastroenterology Department, CDI diagnosis took an average of 14 days, but the positive result was coming out of the Microbiology Department in an average time of 2 days. Therefore, there is a remaining gap of 1012 days in which it would be possible to know the sample results. We could improve the early diagnosis of CDI in IBD outpatients with a better communication with the Microbiology Department. The result of the samples took between 2448 hours to upload on our intranet. Moreover, another problem is the time that the patient delayed going back to the outpatient consultant. Thus, it would be helpful to keep in touch with the Microbiology Department in a more direct way to know the positive results as soon as possible. General characteristics of IBD Our study was performed in a single centre with a limited number of patients. However, it is the first large study about CDI in Spanish IBD patients and the first to evaluate recurrence and outcome in these patients. In our study, IBD patients with CDI were younger than the general population with CDI (>65 were less than 10%). CDI was communityacquired, and the study for CDI diagnosis was requested as an outpatient. Most studies published show that the age in IBD cohorts was much lower than in the general population controls suggesting that patients with IBD would have different risk profile. (42) Thus, our results are consistent with the literature Most IBD patients appear to contract CD as outpatient even in hospitalized patients. If CDI confirms within 48 hours of admission, suggests a community acquisition.(39, 42, 43) In our study, 135 most analyzed CDI episodes were community acquisition without differences with nonCDI patients with a relapse. We could not find differences in the appearance of the infection in autumn and winter. This was probably because the Canary Islands have no seasons, with mostly homogeneous temperatures between 1825ºC all the year round. We found that UC and the rectal localization had more risk for CDI, and moreover UC was an independent risk factor for the CDI development in the multivariate analysis.(30, 47) Crohn´s disease with colonic involvement had a higher risk than small intestine localization for CDI. (43, 104, 105, 107) In addition, in our study, ileal localization was significantly more frequent in the control group. Our results are consistent with the literature; we found only in one study that a more extensive disease seemed to be at greater risk factor than a distal one. (43) In Crohn´s disease, nonstricturing non penetrating behavior was more frequent in CDI episodes than the stricturing one. We found in our serie that CDI was frequent in CD with perianal location and abscesses in the episodes, probably related to concomitant or previous antibiotic treatment. Thus, our findings suggest we should have a high index of suspicion for CDI in IBD patients mainly if they have a colonic involvement (ulcerative colitis and Crohn´s disease with colonic involvement), in CD with an inflammatory behavior and with perianal localization and an abscess in that episode. There were more episodes of CDI and relapses than without CDI, during the first years of our followup. In fact, CDI episodes are frequent during the first 3 7 years (50% and >70% respectively) after IBD diagnosis. It is known that IBD per se is a risk factor for CDI and could be because of the disease has not a completed control of inflammation, and this lack of inflammation control could be a predisposing factor. We do not know whether CD is a cause of IBD or a consequence of the inflammatory state in the intestinal environment and disruption of the normal microbiota. (18) However, the behavior of UC and CD with and without CDI was different: CDI makes the behavior of ulcerative colitis similar to the behavior of Crohn´s disease without CDI. Moreover, UC with CDI seems to have a different behavior as compared with UC without infection. UC with the infection has more probability of relapse and earlier than UC without infection, where the evolution only depends on its natural evolution. In contrast, in CD with the infection the relapses were less frequent when compared with CD without infection, in which the relapse depends on the natural evolution of the disease, without an external element triggering the relapse. Our results are interesting because CDI seems to play a role in the relapses in UC. There are questions unanswered about the role that CD can have in the exacerbations of IBD. (27) Furthermore, in our study we found in more than 10% of the cases, a simultaneous CDI and IBD diagnosis compared with established IBD in the controls. It was an independent risk factor for CDI in IBD patients in the multivariate analysis. Our result is consistent with the literature and is important 136 because could support the role that CD can play in the onset of IBD. The prevalence of CDI in newly diagnosed IBD patients is high (810%) and is independent of the type of disease.(33, 34) IBD episodes with CDI did not usually need hospitalization in our series, but we have found that these episodes had as risk factors treatment with PPIs 3 months before the episodes (similar to outpatients) and antibiotics in the limit of signification. Thus, it would be necessary try to avoid once the PPIs in this patients. The presence of comorbidities were not frequent in IBD patients, but patients with comorbidities had more risk for CDI. In fact, to have comorbidities was an independent risk factor in the multivariate logistic regression for CDI in our study. Nguyen et al.(104) found that the comorbidity increases the risk of acquisition of CDI in IBD patients. We could not identify inflammatory markers that could be predictive factors for CDI development and predictive factors of a complicated CDI. Perhaps, due to our small sample size. In the general population there are laboratory markers of severity but no in IBD patients until now. We found more inflammation (higher levels of CRP) correlated with low levels of hemoglobin and higher levels of inflammation with low nutrition parameters. Albumin<3 gr (hyponutrition) was presented in both groups without differences, but there was a higher proportion in CDI group. Our study tried for the first time investigate the role of fecal calprotectin in CDI in IBD patients. However, we could not obtain significant differences with control group because of small sample size. However, calprotectin levels showed a tendency to be higher in CDI episodes (>500). Moreover, we found a tendency to higher calprotectin levels and clinical severity in our samples: in mild episodes the values had a tendency of being < 200, in moderate episodes, they had a tendency of being >500 and in the severe episode we did not have any samples to evaluate. In our opinion, faecal calprotectin could play a role in the classification of these patients in risk groups and in their followup. We need more studies to evaluate the role of this biological marker in CDI management. Risk factors for acquisition of CD in IBD IBD patients have a different risk profile as compared with the general population. One of the advantages of the database and other large studies is that their sample size has allowed the identification of risk factors associated with CDI. Most important pharmacological risk factors for CDI in the general population are the utilization of broad spectrum antibiotics (destroy the protective intestinal flora) and older age (associated with decreased immune response and increased comorbid conditions). However, it is common that CDI in IBD patients occurs in younger people, without antibiotics exposure and prior healthcare contact. The utilization of antibiotics in IBD is less than in general population, 43% CDI are associated with taking antibiotics 3 months before it.(72) In our study, antibiotics were used in 16% of CDI episodes as compared with IBD patients without CDI and the differences were significant (in the 137 control group, its use was more frequent in CD). Moreover, as in the case of comorbidities, it is less frequent compared with the general population but it is important in the CDI development in IBD patients. In our study antibiotic treatment 3 months prior episodes was an independent risk factor in the multivariate analysis. A stepwise antibiotic treatment in IBD patients would be essential. In our study, PPIs were used significantly more in CDI group than in control group in the univariate analysis, and they were an independent risk factor at the limit of the multivariate logistic regression (but in our population there is an overuse of PPIs, which could be a confusion factor). Antiacids as risk factor for CDI have negative and positive reports. It is thought that the mechanism is related to decrease gastric acid, which increases the transit of the vegetative cells and spores of Clostridium beyond the stomach and cause infection. It is thought that proton pump inhibitors (PPIs) are more important risk factors than other antisecretory agents. In IBD patients, the use of PPIs have been evaluated in a few studies and the number of patients was too small to detect significant effects (35, 111). Recently, in 2015 RamosMartínez et al. (189) studied for the first time in Spain, risk factors in IBD patients for CDI and they found that PPIs treatment was a risk factor for CDI more than antibiotics. They also detected differences in spite of the small sample size. We did not find differences in the use of immunosuppressants at the moment of episodes (40 50% in both groups) between CDI group and control group. Less than 10% of episodes with/without CDI were treated with biological treatment (infliximab and adalimumab) without differences. However, in the subgroup of recurrent episodes of CDI, immunosuppressant and biological treatment were risk factors in univariate and multivariate analysis. In the cohorts studies performed in a single centre is not frequent to be reported as a risk factor, perhaps because most were conducted before the widespread use of immunosuppressant treatment and were underpowered to detect small effect sized. On the contrary, Issa et al. (43) found that immunosuppression defined as the use of thiopurines, methotrexate, and steroids, double the risk of CDI in IBD patients. Schneeweiss et al. (191) did not find an association with infliximab or immunomodulators and the admission of IBD patient with CDI. Moreover, Seicean et al. (29) have suggested in several reported cases that infliximab treatment may be protective. We need more studies to confirm this and to stablish which would be the optimal infliximab treatment regimen for UC with CDI. Outcome In IBD population, the outcome has been different depending on whether the studies were carry out in a single centre, hospitalized patients or with data collected from a database. In our centre, we found a favorable outcome that confirmed the recent and only so far, Spanish study performed by Martínez et al. (189) in a single centre too. Overall, IBD patients with a relapse with CDI did not have 144 marker for developing a severe CDI. Thus, we need specific guidelines for the treatment of CDI in IBD patients. There are few data, and not enough controlled trials about the efficacy of other treatments for CDI in IBD patients such as probiotics and faecal transplantation. Both are used in the general population; faecal transplantation in severe and recurrent CDI episodes but IBD patients it has not yet been investigated in CDI treatment. In our opinion, faecal transplantation seems an option to treat CDI but also IBD per se, but we need controlled studies. Limitations and strengths of our study Our study has the following limitations: it is a retrospective study developed in a single centre with a small sample size. We revised paper medical records, and it was difficult the extraction of some data on severity of the disease. Furthermore, laboratory parameters were not requested in all relapses by physicians. Despite this limitation, our findings are in agreement with previous studies and highlight the most important variables to consider when assessing risk factors for first and recurrent CDI episodes. Moreover, our study is the first in evaluating more than risk factors in CDI in Spanish patients: recurrence and outcome. Our findings could have implications for the treatment and control CDI episodes in IBD patients in our area and can help to establish patients profile at risk for CDI in Spanish IBD patients. Future research We acknowledge that this is just a first step in the medical research on this subject. It would be crucial the creation of a multidisciplinary workgroup to perform European multicenter studies and create protocol for diagnosis, treatment and prevention management in IBD patients. 145 Chapter 5 146 147 6. Chapter 5: Conclusions  We did not find an increase in the number of cases of CDI from June 2007 to June 2015 in our area. The frequency of CDI is not characterized in IBD patients in Spain. Because of its low prevalence, multicenter and prospective studies are needed to evaluate the incidence and prevalence of CDI in IBD patients in Spain.  Direct and fluid communication with the Microbiological Department is crucial to get positive results faster to make the therapeutic decision as early as possible.  We should not routine request a stool sample in all IBD relapses from the start of the process. We should request it when the patients had risk factors for the infection  CDI was frequent during the first years of followup and at IBD diagnosis.  The behavior of UC and CD with and without CDI was different: CDI becomes the behavior of ulcerative colitis similar to the behavior of Crohn´s disease without CDI. UC with the infection has more probability of relapse and earlier than UC without infection. Nevertheless, in CD with the infection the relapses were less frequent compared to CD without infection in which the relapses depend on the natural evolution of the disease.  We must have a higher grade of suspicion:  In patients with active colonic IBD (ulcerative colitis and Crohn´s disease with colonic involvement). We have found CDI more frequent in ulcerative colitis with rectal localization. Ulcerative colitis is an independent risk factor for CDI. Moreover, in Crohn´s disease with an inflammatory behavior, perianal localization and an abscess in that episode.  At IBD diagnosis, there is more risk for Clostridium difficile infection. We have found it to be an independent risk factor for CDI. These results could support the role that CD can play in the onset of IBD.  After any CDI episode, IBD patients have a higher probability of recurrence, especially after the first 8 weeks after stopping treatment. 148  Most CDI episodes occurred in young patients and were communityacquired. The diagnosis was done as an outpatient. Thus, IBD patients have a different risk profile compared with the general population, and IBD per se could play a role in CDI.  Most CDI episodes were mildmoderate. We need to establish prognostic markers to determine the risk of developing a severe CDI with prospective and multicenter studies. ESCMID guideline for the general population, considers IBD per se, as a prognostic marker of severe CDI.  Percentage of hospitalization was low, but CDI patients needed significantly more. Most episodes had a moderate severity. Thus, we need to improve the communication with the emergency room to hospitalize only the patients who need it.  We have not found any inflammatory biomarker in blood or stool or other laboratory parameter to be able to predict the severity of the CDI.  In our area, the subgroup of patients over 65 years old seemed to have a different behavior with a worse outcome, prognosis, and more recurrent episodes.  We did not find that immunossupressant and biological treatments were a risk factors for CDI except in recurrent episodes  In our study in Spanish IBD patients, the independent risk factors in the multivariate analysis for CDI were: ulcerative colitis, at the time of diagnosis of IBD, antibiotics 3 months before episodes and comorbidity. PPIs 3 months before episodes was a risk factor in the univariate analysis. Two of these risk factors are preventable ones (antibiotics and PPIs), another we can suspect it early (at IBD diagnosis), and comorbidity is not modifiable but can be improved.  Recurrent CDI is a frequent event and the independent risk factors for its development were: ulcerative colitis, immunosuppressant, and biological treatment.  CDI did not have any influence on the outcome of the IBD relapse: no more therapeutic escalation, no more need for hospitalizations and long stay at hospital, no more need for surgery and finally no more mortality. 149 Chapter 6 150 151 7. Chapter 6: Our proposals to modify the management of CDI Our proposals to modify the management of CDI in IBD patients in our area, according to our study are: Prevention strategies  In our hospital, it would be recommended the creation of a multidisciplinary workgroup for the elaboration of CDI guidelines for diagnosis, treatment and prevention strategies. We think that the following departments should be included: Microbiology, Infectious Disease, Internal Medicine, Preventive Medicine and Gastroenterology Departments.  Awareness campaigns for a rational use of PPIs and broad spectrum antibiotics in outpatients and hospitalized patients. Both, are risk factors for CDI in our area.  Preventive Department has done for a long time an impressive work on preventive strategies (contact isolation, hand washing, single rooms) to avoid CDI transmission in hospitalized patients.  Elaboration of a specific protocol with Microbiology department could be useful to serotype CD in the stools samples of patients affected by the infection. We do not know if the hypervirulent ribotype 027 is or not in our hospital. Diagnosis of CDI in our IBD patients In general, we must have a higher grade of suspicion of CDI in IBD patients:  Early suspicion in patients with a risk profile in our area. Thus, we can start the specific treatment as soon as possible: Ulcerative colitis; patients with comorbidities, taking PPIs and antibiotics and at the time of diagnosis of IBD.  Direct and fluid communication with the Microbiological Department is crucial to get positive results faster to make the therapeutic decision as early as possible.  We should not routine request a study of stools in all IBD relapses from the start of the process. We should solicitate it when the patients have risk factors for the infection or do not respond to the 152 optimization of basal treatment, corticosteroids, intensification of treatment and in hospitalized patients.  One stool sample is enough to diagnose CDI except if we suspect a reinfection.  It is not necessary to confirm the microbiological resolution with control stool samples after treatment if the patients have improved. Treatment of CDI in our IBD patients  One of the most relevant aspects of management of CDI is to prevent recurrences. Specifically, the treatment of the recurrent episodes and the patients who are at risk for recurrent CDI is a hard challenge.  In our area, we have a high percentage of recurrences after a first episode. Thus, we should use specific antibiotics that were effective to treat the infection and prevent recurrences at the same time.  How should we treat IBD patients with CDI in an episode? Is the same UC and CD? We are going to suggest the following treatment in our area based on our results, waiting for specific guidelines in Europe:  The first episode of nonsevere CDI in outpatients: We could wait for results of stool samples, optimize the basal treatment of patients and start antibiotic treatment if positive result. We could begin with metronidazole (500 mg three times daily 10 days as the first option) in general in UC and CD but if we had other risk factors (antibiotics, PPIs, comorbidities, at IBD diagnosis) and UC, we think that we could start with vancomycin (125 mg four times daily 10 days) for the risk of recurrence.  Treatment for the first recurrence: we should use oral vancomycin, 125 mg four times daily 10 days  Treatment of severe CDI and hospitalized patients: we should use oral vancomycin, 125 mg four times daily 10 days 153  Multiple recurrent episodes (more than one relapse): we should use oral vancomycin, 125 mg four times daily 10 days followed by pulse regimen (125500 mg/day every 23 days) for at least 3 weeks.  We found a high percentage of recurrence in patients over 65 years old, we should start the treatment with vancomycin, 125 mg four times daily 10 days for the risk of recurrence  One of the main goals of IBD treatment is to avoid corticosteroids. We could not treat with corticosteroids the mildmoderate episodes (episodes without severity clinical or in the laboratory parameters). Therefore, it would be beneficial for the patient to start with antibiotic treatment alone in mild episodes without risk of complications or recurrences. We need prospective, controlled trials of CDI treatment in IBD patients. In hospitalized patients, it seems reasonable to start with intravenous corticosteroids and metronidazole or vancomycin while awaiting the results of stool samples. In outpatients in better condition, decisionmaking could await the result of stool testing.  We need to elaborate specific protocols for treatment of CDI in IBD patients specifically. Thus, probably after a first recurrence, severe episodes and patients with a higher risk of recurrences, we should use vancomycin as the first line: in our area, UC recurs more than CD. Therefore, in UC treatment we should use vancomycin at least after the first recurrence. Moreover, should we treat with vancomycin all CDI in UC from first episodes or only in a subgroup of patients such as hospitalized one or at risk for recurrence or with severe episodes?  We need prospective and multicentre studies in IBD patients to define risk groups with a worse evolution and evaluate the best strategies for them based on the age of the patient, biological markers of severity, and underlying comorbidities.  We need prospective and controlled multicenter studies to evaluate the best treatment option for each subgroup of our IBD patients based on the risk of recurrence, the number of episodes and severity.  The results of our study can be helpful to define risk groups for CDI. Additional or new interventions may be required to prevent the episodes (appropriate treatment/ avoid or prevent risk factors). In our opinion, it would be necessary to create a multidisciplinary workgroup to develop guidelines for the management of this infection in IBD patients: diagnosis, treatment and prevention strategies.