INTRODUCTION TO CLOSTRIDIUM DIFFICILE INFECTION SLIDE RESOURCE SET FDX/13/0068/EU | August 2013

Introduction to Clostridium difficile C. difficile is a Gram-positive, spore-forming, anaerobic bacillus that was first identified in C. difficile is the leading cause of infective nosocomial diarrhoea in industrialised countries 2 C. difficile passes through a life cycle where it exists in two forms; as vegetative cells and as spores 3 1.Hall IC, O’Toole E. Am J Dis Child 1935;49:390–402; 2.Crobach MJT, et al. Clin Microbiol Infect 2009;15:1053–66; 3.Poutanen S, Simor AE. CMAJ 2004;171:51–8. Vegetative formSpores surrounding a vegetative cell FDX/12/0076/EUa | MW101

Clinical presentation of C. difficile infection (CDI) Asymptomatic colonisation Diarrhoea without colitis –Watery –Mucus but no blood Colitis without pseudomembrane formation Pseudomembranous colitis Fulminant colitis Bauer MP, et al. Clin Microbiol Infect 2009;15:1067–79; Bartlett JD, Gerding DN. Clin Infect Dis 2008;46:S12–8. Increasing severity Normal, healthy colon Pseudomembranous colitis FDX/12/0076/EUb | SJ103

Other signs and symptoms of CDI, including severe colitis Vomiting Abdominal tenderness Fever (rigors) Dehydration Leucocytosis Hypoalbuminaemia Exhaustion Bauer MP, et al. Clin Microbiol Infect 2009;15:1067–79. AI/12/0055/EUg | DM104

Risk factors for CDI 1.Cohen SH, et al. Infect Control Hosp Epidemiol 2010;31:431–55; 2.Bignardi GE. J Hosp Infect 1998;40:1–15. There are numerous reported risk factors for CDI Broad- spectrum antibacterials 1 Immuno- compromised 2 Older age 2 Severity of underlying diseases 2 Prolonged stay in hospital/ care home 2 ICU stay 2 Nasogastric tube/ GI surgery 2 PPIs 2 GI, gastrointestinal; ICU, intensive care unit; PPI, proton pump inhibitor FDX/12/0076/EUb | SJ108

Key steps in the pathogenesis of CDI Kelly CP, LaMont JT. Annu Rev Med 1998;49:375–90. Antibacterial therapy Alteration of colonic microflora C. difficile exposure and colonisation Release of toxins A and B Colonic mucosal injury and inflammation FDX/13/0038/EUb | VA002

The infectious cycle of transmission and recurrence of CDI Adapted from Sunenshine RH, et al. Cleve Clin J Med 2006;73:187–97. 1.Ingestion of spores transmitted from other patients, via hands of healthcare personnel and the environment 2. Germination into growing (vegetative) cells 3. Disruption of normal colonic microflora allows colonisation and overgrowth of C. difficile in the colon 4.Toxin production leads to inflammation and damage to intestinal cells 5. Transmission of spores via the faecal–oral route C. difficile Toxins FDX/12/0076/EUb | SJ101

Cycle of infection with C. difficile Adapted from Poutanen SM, Simor AE. CMAJ 2004;171:51–8. C. difficile spores and vegetative cells are ingested Most vegetative cells are killed in the stomach, but spores can survive the acid environment C. difficile spores germinate in the small bowel upon exposure to bile acids Flagellae facilitate C. difficile movement C. difficile multiplies in the colon Gut mucosa facilitates adherence to the colonic epithelium ColonStomach Small bowel SporesVegetative cells FDX/13/0038/EUb | VA001

CDI is toxin mediated Toxin A* 1 –Referred to as the ‘enterotoxin’ because of the easily demonstrated effects of purified toxin in animal intestinal models –Likely to be intimately involved in CDI pathogenesis Toxin B* 1 –Potent cytotoxin –Structurally similar to toxin A but effects in animal intestinal models have not been easy to demonstrate –Likely to be intimately involved in CDI pathogenesis Binary toxin –Unrelated to toxins A and B 1 –Present in the epidemic BI/NAP1/027 strain 2 –Role in pathogenesis uncertain 2 1.Rupnik M, et al. Nat Rev Microbiol 2009;7:526–36; 2.Warny M, et al. Lancet 2005;366:1079–84. *Large, single-unit, glucosylating toxins; BI/NAP1, characterised as group BI by restriction endonuclease analysis and North American pulse-field type 1 by gel electrophoresis FDX/12/0076/EUb | SJ134

Role of host antibody-mediated responses in CDI pathogenesis Adapted from Rupnik M, et al. Nat Rev Microbiol 2009;7:526–36. Patients with risk factors for CDI, including antibacterial use in hospital setting Exposure to toxigenic C. difficile accompanied by IgG response to toxin A C. difficile negative Asymptomatically colonised Symptomatic CDI Exposure to toxigenic C. difficile without an IgG response to toxin A Exposure to non-toxigenic C. difficile IgG, Immunoglobulin G antibody FDX/12/0076/EUb | SJ102

Impact of CDI on short- and long-term patient management CDI may necessitate treatments for underlying diseases to be reduced in intensity or suspended –Alterations to treatment plans may irreversibly affect long-term outcomes 1 Episodes of CDI arising in the ICU may prolong ICU stay and overall hospitalisation 2 –Excess ICU length of stay: 2.2 days (p=0.069) –Excess hospital length of stay: 4.5 days (p=0.030) 1.Hautmann MG, et al. Radiat Oncol 2011;6:89; 2.Kenneally C, et al. Chest 2007;132:418–24. FDX/12/0076/EUb | SJ119

Length of hospital stay among patients with CDI by country Wiegand PN, et al. J Hosp Infect 2012;81:1–14. FDX/12/0076/EUd | DN139 EU, European Union Length of stay (days) Belgium France Germany Ireland Spain Switzerland Netherlands UK EU

Association of CDI with hospital readmissions Dubberke ER, et al. Emerg Infect Dis 2008;14:1031–8. In this study, CDI patients were significantly more likely to be readmitted to hospital than controls; the readmission rate attributable to CDI was 19.3% Kaplan–Meier estimates of time until hospital readmission for matched pairs (N=580) in patients with and without CDI Time since hospital discharge (days) Proportion without readmission No CDI CDI Log-rank p<0.001 FDX/12/0076/EUd | DN149

Association of CDI with mortality Dubberke ER, et al. Emerg Infect Dis 2008;14:1031–8. 38% of patients with CDI died within 180 days after hospital admission vs 12% of patients without CDI Kaplan–Meier survival estimates for cohort (N=18,050) in patients with and without CDI Time since hospital discharge (days) Cumulative survival No CDI CDI Log-rank p< FDX/12/0076/EUd | DN150

Mortality rates in studies of CDI In a recent pan-European hospital-based survey: 1 –~2% of patients with CDI died as a result of the infection –CDI contributed to mortality in a further 7% of cases In a case-control study in Canada: 2 –~7% of patients with CDI died as a result of the infection –CDI contributed to mortality in a further 8% of cases 1.Bauer MP, et al. Lancet 2011;377:63–73; 2.Loo VG, et al. N Engl J Med 2005;353:2442–9. FDX/12/0087/EUu | slide 013

Mortality rates associated with CDI across Europe Wiegand PN, et al. J Hosp Infect 2012;81:1–14. Data from a systematic review found the weighted average 30-day mortality from CDI ranged from 3–30% Weighted average 30-day mortality in patients with healthcare facility-acquired CDI by country day mortality (%) Austria Denmark Finland France Germany Ireland Luxembourg Spain Switzerland The Netherlands UK 14% 16% 14% 3% 16% 7% 15% 22% 9% 20% 30% FDX/12/0076/EUd | DN108

Age-specific incidence of CDI and attributable mortality Loo VG, et al. N Engl J Med 2005;353:442–9. FDX/12/0076/EUb | SJ113

Factors contributing to risk of mortality from CDI Advancing age 1,2 Older age and severity associated with the epidemic 027/NAP1 strain 3 Use of metronidazole for severe disease 4 Haematological malignancy and severe disease 5 Comorbidity –Renal disease 4 –Ischaemic heart disease 4 –Inflammatory bowel disease 6 –Liver disease (cirrhosis) 7 1.Loo VG, et al. N Engl J Med 2005;353:2442–9; 2.Bauer MP, et al. Lancet 2011;377:63–73; 3.Miller M, et al. Clin Infect Dis 2010;50:194–201; 4.Wilson V, et al. Clin Infect Dis 2010;50:e77–81; 5.Dubberke ER, et al. Infect Con Hosp Epidemiol 2007;28:208–11; 6.Ananthakrishnan AN, et al. Gut 2008;57:205–10; 7.Bajaj JS, et al. Am J Gastroenterol 2010;105:106–13. FDX/12/0076/EUb | SJ110

Toxic megacolon Increased mortality: a result of CDI severity 1.Jaber MR, et al. Am J Gastroenterol 2008;103:3195–203; 2.Longo WE, et al. Dis Colon Rectum 2004;47:1620–6; 3.Berman L, et al. J Clin Gastroenterol 2008;42:476–80; 4.Dallal RM, et al. Ann Surg 2002;235:363–72. Up to 8% of patients develop fulminant CDI 1 Fulminant colitis accounts for serious complications including toxic megacolon 2 Many patients with toxic megacolon require emergency surgery (colectomy) to remove dead sections of the colon 2–4 –Approximately half of all patients who undergo colectomy die 3,4 FDX/12/0076/EUb | SJ111

Recurrence of CDI Recurrence of CDI has been identified by the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) as the most important problem in the treatment of CDI 1 CDI recurrence is common, occurring in up to 25% of cases within 30 days following treatment 2–4 Recurrence appears to be related to a combination of: 5 –A failure to re-establish the colonic microflora –The presence in the intestines of spores of C. difficile –A sub-optimal host immune response to the infecting organism and its toxins 1.Bauer MP, et al. Clin Microbiol Infect 2009;15:1067–79; 2.Louie TJ, et al. N Engl J Med 2011;364:422–31; 3.Lowy I, et al. N Engl J Med 2010;362:197–205; 4.Bouza E, et al. Clin Microbiol Infect 2008;14(Suppl 7):S103–4; 5.DuPont HL. N Engl J Med 2011;364:473–4. FDX/12/0076/EUb | SJ121

The incidence of recurrent CDI 1.Louie TJ, et al. N Engl J Med 2011;364:422–31; 2.Lowy I, et al. N Engl J Med 2010;362:197–205; 3.Bouza E, et al. Clin Microbiol Infect 2008;4(Suppl 7):S103–4; 4.McFarland LV, et al. Am J Gastroenterol 2002;97:1969–75; 5.McFarland LV, et al. JAMA 1994;271:1913–8. 1 st recurrence of CDI Recurrence(s) of CDI ~45–65% of patients have further recurrences 4,5 Up to 25% of patients have recurrent CDI 1–3 Initial episode of CDI FDX/12/0076/EUb | SJ122

Risk factors for a recurrence of CDI Immunocompromised state 1 Exposure to other antibacterial agents that disrupt the normal colonic microflora 2–5 Renal impairment 6,7 Aged 65 years or over 2,4,8 Impaired immune response to C. difficile toxin A 2 Severe underlying disease 2 Prolonged hospitalisation 8 ICU stay 5 1.Cohen MB. J Pediatr Gastroenterol Nutr 2009;48(Suppl 2):S63–5; 2.Kyne L, et al. Lancet 2001;357:189–93; 3.Bauer MP, et al. Clin Microbiol Infect 2009;15:1067–79; 4.Bauer MP, et al. Lancet 2011;377:63–73; 5.Hu MY, et al. Gastroenterology 2009;136:1206–14; 6.Do AN, et al. Clin Infect Dis 1998;26:954–9; 7.Bauer MP, et al. Clin Microbiol Infect 2011;17(Suppl 4):A1–4; 8.Pépin J, et al. Clin Infect Dis 2005;40:1591–7. FDX/12/0076/EUr | SJ204

Laboratory detection of CDI The recommended approach is to demonstrate: 1,2 Organism in stool –GDH or culture: do not distinguish toxigenic vs non-toxigenic –Need confirmatory test for toxigenicity Toxin in stool –Cell culture toxin cytotoxicity –EIA to detect toxins A and/or B Toxin from organism –Culture cytotoxicity Toxin genes in organism –PCR for toxin B gene 1.Crobach MJT, et al. Clin Microbiol Infect 2009;15:1053–66; 2.Kelly CP, LaMont JT. Annu Rev Med 1998;49:375–90. FDX/12/0087/EUu | slide 018 EIA, enzyme immunoassay; GDH, glutamate dehydrogenase; PCR, polymerase chain reaction

− − + + − − + + ESCMID recommended diagnostic algorithm for CDI Adapted from Crobach MJT, et al. Clin Microbiol Infect 2009;15:1053–66. EIA to detect TcdA and TcdB EIA to detect GDH, or real- time PCR to detect TcdB EIA to detect GDH,or real-time PCR to detect TcdB, or cytotoxicity assay High clinical suspicion: toxigenic culture No CDI CDI is diagnosed No CDI CDI is diagnosed C. difficile toxins are not detectable in faeces but C. difficile is present; CDI cannot be excluded + + − − − − + + Toxin detection or bacterial detection EIA, enzyme immunoassay; GDH, glutamate dehydrogenase; PCR, polymerase chain reaction EIA to detect TcdA, and TcdB, or cytotoxicity assay FDX/12/0076/EUo | CS209

CDI imposes a significant burden on hospitals Infection control and environmental decontamination 1 Patient isolation and ward closures 1 Monitoring and surveillance 2 Laboratory tests 3 Surgical costs 1,3 ICU length of stay 4 Hospital length of stay 2,4,5 1.Kuijper EJ, et al. Clin Microbiol Infect 2006;12:2–18; 2.Wiegand PN, et al. J Hosp Infect 2012;81:1–14; 3.Ghantoji SS, et al. J Hosp Infect 2010;74:309–18; 4.Kenneally C, et al. Chest 2007;132:418–24; 5.Vonberg RP, et al. J Hosp Infect 2008;70:15–20. FDX/12/0076/EUb | SJ120

CDI: a public health challenge The recorded incidence and severity of CDI have increased in many settings in recent years, including in people previously thought to be at lower risk 1–6 Clusters/outbreaks of CDI cause ward closures and disruption of hospital activity 7 There is a considerable burden of morbidity and mortality due to CDI 7 The resultant effect is an erosion of public confidence concerning the risk of healthcare-associated infection Also, the financial burden of disease is high 8 1.Bauer MP, et al. Lancet 2011;377:63–73; 2.Vonberg RP, et al. Emerg Infect Dis 2007;13:179–80; 3.Soler P, et al. Infect Control Hosp Epidemiol 2008;29:887–9; 4.Lyytikäinen O, et al. Emerg Infect Dis 2009;15:761–5; 5.Søes L, et al. Euro Surveill 2009;14:1–4; 6.CDC. MMWR Morb Mortal Wkly Rep 2005;54:1201–5; 7.Kuijper EJ, et al. Clin Microbiol Infect 2006;12:2–18; 8.Wilcox M, et al. J Hosp Infect 1996;34:23–30. FDX/12/0076/EUa | MW103