OBJECTIVETo investigate the epidemiological and clinical features of calicivirus-associated diarrhea in hospitalized children in Chengdu, China in recent years.

METHODSThe clinical data of 267 children with calicivirus-associated diarrhea aged <5 years who were hospitalized in Chengdu Women and Children's Central Hospital (the only sentinel hospital for sample collection of pediatric viral diarrhea in Chengdu, Sichuan) between January 2012 and December 2014 were retrospectively studied.

RESULTSAmong the 267 children, 200 (74.9%) were aged less than 1 year. The infection rate of calicivirus was 28.4%, 21.6%, and 27.1% in 2012, 2013, and 2014, respectively. Calicivirus was prevalent in summer and autumn (August to October). The detection rate of Norovirus II was 85.8% (229/267), and 244 children (91.4%) experienced an acute clinical course. Watery stool was the most common change in stool properties (82.0%, 219 children), and some specimens showed mucus and/or blood. Most children had moderate to severe fever. One hundred and thirty-eight children (53.9%) experienced a reduced serum prealbumin level. One hundred and fifty-nine children (59.6%) experienced flora imbalance.

CONCLUSIONSCalicivirus has become one of the major pathogens for diarrhea in children aged <5 years in Chengdu, with Norovirus II as the dominant strain. Calicivirus is prevalent in summer and autumn. Infants aged <1 year are the main population affected by calicivirus-associated diarrhea, with watery stool as the most common manifestation.