High morbidity and mortality of Clostridium difficile infection and its associations with ribotype 002 in Hong Kong

Summary Objectives We aim to study the disease burden, risk factors and severity of Clostridium difficile infection (CDI) in Hong Kong. Methods We conducted a prospective, case–control study in three acute-care hospitals in Hong Kong. Adult inpatients who developed CDI diarrhoea confirmed by PCR (n = 139) were compared with the non-CDI controls (n = 114). Ribotyping of isolates and antimicrobial susceptibility testing were performed. Results The estimated crude annual incidence of CDI was 23–33/100,000 population, and 133–207/100,000 population among those aged ≥65 years. The mean age of CDI patients was 71.5. Nursing home care, recent hospitalization, antibiotics exposure (adjusted OR 3.0, 95% CI 1.3–7.1) and proton-pump inhibitors use (adjusted OR 2.2, 95% CI 1.2–3.9) were risk factors. Severe CDI occurred in 41.7%. Overall mortality was 16.5% (among severe CDI, 26.5%). The commonest ribotypes were 002 (22.8%), 014 (14.1%), 012 and 046 ; ribotype 027 was absent. Ribotype 002 was associated with fluoroquinolone resistance and higher mortality (47.6% vs . 12.7%; adjusted HR 2.8, 95% CI 1.1–7.0). Conclusions Our findings show high morbidity and mortality of CDI in the older adults, and identify ribotype 002 as a possible virulent strain causing serious infections in this cohort.