Furuya-Kanamori L1, Riley TV2,3, Paterson DL4, Foster NF2,3, Huber CA4, Hong S2, Harris-Brown T4, Robson J5, Clements AC6. A comparison of Clostridium difficile ribotypes circulating in Australian hospitals and communities. J Clin Microbiol 2016; Epub ahead of print. doi:10.1128/JCM.01779-16
Clostridium difficile infection (CDI) is becoming less exclusively a healthcare-associated (HA) infection. Community-associated (CA)-CDI has increased over the past decades. It has been postulated that asymptomatic toxigenic C. difficile (TCD)-colonised patients may play a role in the transfer of C. difficile between the hospital setting and the community. Thus, to investigate the relatedness of C. difficile across the hospital and community settings, we compared host and pathogen characteristics among symptomatic and asymptomatic patients in these two settings over a 3-year period. Two studies were simultaneously conducted, the first study enrolled symptomatic CDI patients from two tertiary hospitals and the community in two Australian states; while the second study enrolled asymptomatic TCD-colonised patients from the same tertiary hospitals. A total of 324 patients (96 HA-CDI, 152 CA-CDI and 76 TCD-colonised) were enrolled. The predominant C. difficile ribotypes isolated in the hospital setting corresponded with those isolated in the community, 79% of the C. difficile isolates from the hospitals had a matching ribotype isolated from the community, suggesting that transmission between these two settings is occurring. Toxigenic C. difficile strains causing symptomatic infection were similar to those causing asymptomatic infection and patients exposed to antimicrobials prior to admission were more likely to develop symptomatic infection (OR 2.94; 95%CI 1.20-7.14). Our findings suggest that development of CDI symptoms in a setting without establishment of hospital epidemics with binary toxin producing C. difficile strains may be driven mainly by host susceptibility and exposure to antimicrobials, rather than by C. difficile strain characteristics.
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