title: Prevalence and molecular epidemiology ofClostridium difficileinfection in Thailand.
abstract: Little is known aboutClostridium difficileinfection (CDI) in Asia generally, and specifically in Thailand. Given the high prevalence of inappropriate antibiotic usage in this region, CDI is likely to be common. This study investigated the prevalence and molecular epidemiology of CDI in Thailand. Stool specimens collected from inpatients with diarrhoea at Siriraj hospital in Bangkok (n=422) were cultured on ChromID Cdiff agar and any presumptiveC. difficilecolonies were identified, PCR ribotyped and toxin profiled. As part of the routineC. difficiletesting at Siriraj Hospital, 370 specimens also underwent testing with the BD MAX Cdiff assay to detect the presence oftcdB.With direct culture, 105 different isolates ofC. difficilewere recovered from 23.7% (100/422) of the stool specimens. The prevalence of toxigenic and nontoxigenic isolates was 9.2% (39/422) and 15.6% (66/422), respectively. Of the toxigenic isolates, 69.2% (27/39) and 30.8% (12/39) weretcdAandtcdBpositive (A+B+), and A-B+, respectively; none contained binary toxin genes. The five most prevalent ribotypes (RTs) were 014/020 group (17/105), 010 (12/105), 017 (12/105), 039 (9/105) and 009 (6/105). Using toxigenic culture as the reference standard, the sensitivity, specificity, positive predictive value and negative predictive value of the BD MAX Cdiff assay were 68.6, 95.1, 63.2 and 96.1%, respectively. The high proportion of A-B+, RT 017 strains emphasises the need for diagnostic tests that detect either both toxins or justtcdB.Continued surveillance that involves stool culturing will allow molecular tracking and assist in elucidating the epidemiology of CDI in Thailand.
authors.affiliation: Microbiology and Immunology, School of Pathology and Laboratory Medicine, The University of Western Australia, Crawley, Western Australia, Australia.
authors.forename: P
authors.initials: P
authors.lastname: Putsathit
authors.affiliation: Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: M
authors.initials: M
authors.lastname: Maneerattanaporn
authors.affiliation: Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: P
authors.initials: P
authors.lastname: Piewngam
authors.affiliation: Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: P
authors.initials: P
authors.lastname: Kiratisin
authors.affiliation: Microbiology and Immunology, School of Pathology and Laboratory Medicine, The University of Western Australia, Crawley, Western Australia, Australia; Department of Microbiology, PathWest Laboratory Medicine, Queen Elizabeth II Medical Centre, Nedlands, Western Australia, Australia.
authors.forename: T V
authors.initials: TV
authors.lastname: Riley
keywords: BD MAX Cdiff assay; Clostridium difficile; PCR ribotype; epidemiology; prevalence; toxigenic culture