Clostridium Difficile Infection (CDI) Alistair McGregor Hobart Pathology Royal Hobart Hospital TIPCU

Clostridium Difficile Infection (CDI) Alistair McGregor Hobart Pathology Royal Hobart Hospital TIPCU

Disclosures I am not Tom Riley The Fidaxomicin guys brought me dinner once

Outline ASID/AICA position statement Infection control guidelines for patients with Clostridium difficile infection in healthcare settings. Rhonda L. Stuart, Caroline Marshall, Mary-Louise McLaws, Claire Boardman, Philip L. Russo, Glenys Harrington and John K. Ferguson Pathogenesis Epidemiology Diagnostics Prevention Treatment Healthcare Infection 16(1) 33-39

Pathogenesis

C. Difficile Anaerobic Gram positive spore forming toxin producing bacteria. Fundamental requirements for disease 1. Exposure to the organism 2. A disrupted microbiome 3. Toxin production and 4. Susceptibility to the toxin Laffer NEJM 372;16 Squire Curr Top Micro Immunol 2013;365

Epidemiology

Other risks? Community Acquired CDI Common France 28% USA 34% Australia 30% Increasing? Different demographic Younger, less antibiotic exposure Food reservoir/s? Lessa NEJM 372;9: 825-833 Wozniak Healthcare Infection 20(2) 72-77

Beyond the usual suspects? Old paradigm C. diff. acquired from symptomatic patients ( usual supects ) Not true Pittsburgh 25% cases linked to asymptomatic carriers Oxfordshire only 35% of cases linked to previous case 13% ward contact, 19% hospital contact, rest? intermediate source 45% isolates genetically distinct Donskey NEJM 369;13:1263-1264 Curry CID 2013;57:1094 1102 Eyre NEJM 369;13:1195-1205

Diagnostics

Detect Using Comments Organism Culture Sensitive but not specific Slow Gives isolate for typing etc GDH Sensitive but not specific Toxin Indirectly Culture + cell culture (Cytotoxin) Sensitive (overly?) Slow Culture + EIA Sensitive (overly?) Slow Toxin Directly Cell culture (Cytotoxin) Sensitive (Gold standard) Slow EIA Specific but not sensitive Rapid Toxin coding genes NAAT Sensitive but not specific Rapid Expensive

Historically - A dog s breakfast 70 s 80 s Culture and cytotoxin assay Slow, fiddly but still the gold standard 80 s 90 s EIA Rapid but insensitive. Under diagnosis? 90 s NAAT testing Sensitive but not specific? Over diagnosis?

ASID/AICA Guidelines How often to test Not too little - low threshold Not to much not if no diarrhoea* repeat test in same episode test of cure How to test EIA alone inadequate But is it really?

New learnings Planche et al (UK) Presence of toxin ( direct = in stool) correlates with clinical outcome New category for organism/gene positive but toxin negative = potential C. difficile excretor Polage et al (USA) CDI complications and deaths confined to patients with positive ( direct ) toxin NAAT positive, toxin negative patients outcomes = those who were C. difficile negative Planche Lancet Infect Dis 2013;13:936-45 Polage JAMA Intern Med. 2015 Over diagnosis of Clostridium difficile Infection in the Molecular Test Era

New (UK) Definitions Culture or GDH or NAAT Toxin (Direct) Definition Positive Positive CDI Treat. Isolate. Notify nationally Positive Negative Potential CD excretor. Don t treat. Isolate. Notify locally? Negative Negative CD negative ND REPORTING OF CLOSTRIDIUM DIFFICILE

Potential impact on surveillance USA UK

Prevention

First principles Minimise /prevent exposure to C. difficile Maintain / protect the host gut microbiome

Exposure Food Over to you Tom! Environment Hypochlorite Enhanced environmental cleaning Other Hydrogen peroxide, UV light, Chlorhexidine bathing Gerding CID 2008;46:S43-9 Dancer Clin Micro Review 2014;27(4): 665-690 Gould UpToDate Sep 2015

Exposure Hand hygiene Generally accepted as being important despite lack of solid evidence AICA/ASID guidelines: role of ABHR v soap and water Contact precautions Again seems a good idea but limited hard evidence In best case scenario prevent only 35% of cases Gerding CID 2008;46:S43-9 Dancer Clin Micro Review 2014;27(4): 665-690 Gould UpToDate Sep 2015

The microbiome Probiotics? Few RCTs Most studies single - centre Reproducibility not shown Different agents studied Therapeutic indication not always clear Current (and pending) Australian treatment guidelines do not recommend

The microbiome AMS Good evidence of benefit Key agents: Clindamycin Fluoroquinolones 3GCs Recent meta-analysis Restrictive programs most effective Particularly in Geriatric settings Feazel JAC 2014; 69(7):1748-54

Treatment

Lots happening New antimicrobials Fidaxomicin Rifaximin Others in development Bacteriotherapy FMT FMT by pill In development Defined bacterial mixtures, spores of non toxigenic C. difficile Immunotherapy In trials Anti-toxin HuMabs C. difficile vaccine

Summary Take homes

CDI = ongoing challenge to the health care system HCF will continue to see importation of CD both symptomatic and asymptomatic shedders Good diagnostics are fundamental to individual case management and surveillance Need to understand how and how much your facility is testing

Continue to work to minimise exposure Particularly in outbreak settings But AMS arguably even more important New treatments on the way Non antimicrobial treatments possible game changers, particularly for recurrent disease, but potentially have their own problems (FMT) and cost will be an issue

And finally Progress is possible But.. (sorry Brett).. some things will never change

Four more years boys

Thanks