Epidemiology and risk factors for Clostridium difficile–associated diarrhea in adult inpatients in a university hospital in China

•To our knowledge, this is the first prospective study of Clostridium difficile–associated diarrhea in Jiangsu Province, Eastern China.•The prevalence of toxigenic and nontoxigenic isolates was 14.29% and 1.59%, respectively.•All toxigenic strains were tcdA+/tcdB+, and 1 binary toxin positive strain was reported.•An outbreak of ST35 C difficile infection occurred in China for the first time.•Coloclysis and diabetes were found to be independent risk factors. Clostridium difficile–associated diarrhea (CDAD) is an important disease with rising incidence and mortality in western countries. However, studies about CDAD in China are limited. The aims of this study are to investigate the epidemiology and risk factors of CDAD in a university hospital located in Eastern China. Diarrhea samples of all adult inpatients were collected for C difficile culture prospectively from August 2013-April 2014. Suspected colonies were identified by biochemical identification cards. Confirmed C difficile isolates were further analyzed for the presence of toxin genes and typed by polymerase chain reaction ribotyping. Patient demographics, presumed risk factors, clinical manifestations, and laboratory findings were collected through inpatient medical record systems retrospectively. In total, 45 stains of toxigenic C difficile were isolated from 315 nonrepetitive diarrhea samples. The isolation rate was 14.29% (45/315). No RT027/ST1 strain was found. An outbreak of CDAD occurred in the digestive ward and was finally found to be caused by ST35 strains during this study. Coloclysis and diabetes were found to be independent risk factors of CDAD, besides the common risk factors previously reported. CDAD is not uncommon in Chinese hospitals. C difficile ST35 as a new strain causing outbreaks should be noticed. Coloclysis and diabetes are new independent risk factors for CDAD, and further study is needed.