Low colonization rates of Clostridium difficile among patients and healthcare workers at Örebro University Hospital in Sweden.

The aim of this study was to investigate the rate of asymptomatic colonization rate of Clostridium difficile among both healthcare workers (HCWs) and patients in a hospital ward in Sweden. In a prospective observational study, asymptomatic HCWs (n = 22) (22/60; 37%) attending patients in an infectious disease ward in Sweden participated and were screened once for C. difficile. At the same time, 58 consecutive patients (58/227; 26%) admitted to the same ward were screened for C. difficile, first at admission and thereafter two times weekly. Fecal samples were obtained by rectal swabs and cultured anaerobically using both cycloserine-cefoxitin-fructose agar and enrichment (Cooked Meat broth). All samples were also tested by loop-mediated isothermal amplification and isolates were tested for the presence of toxin A or B by enzyme immunoassay. None of the analyzed fecal samples from HCWs contained C. difficile. Among the patients during a 2-month observational period, three of the 58 patients (5.2%) were culture positive regarding C. difficile on admission and one additional patient became asymptomatically colonized with C. difficile during the hospital stay. Thus, the colonization rates were 0% (0/22) (95% confidence interval (CI): 0-15.4%) among HCWs and 5.2% (3/58) (95% CI: 1.1-14.4%) among patients at admission. As the HCWs were screened only once, we have not studied transient colonization. In conclusion, with observed low colonization rates, we find no support that HCWs would be an important source for C. difficile transmission.