Detection and typing of caliciviruses from patients with acute diarrhea in Hangzhou area, 2009 - 2010

Abstract

To investigate the molecular-epidemiologic characteristics and genotypes of human calicivirus (HuCVs) in acute diarrhea patients in Hangzhou from 2009 to 2010. Epidemiologic data and fecal specimens were collected from patients with acute diarrhea. HuCVs of 920 specimens were detected by PCR. PCR products of several positive samples were randomly selected and sequenced. All the sequences were analyzed, phylogenetically. 201 HuCVs positive cases were identified from 920 facal specimens (21.8%). 25 isolates would include norovirus GI-type, GII-type for 170 strains and sapovirus for 11 strains. Norovirus GI-type and GII-type were detected in four specimens at the same time. Other specimens were mixed infection with norovirus GII-type and sapovirus. Genotypes of HuCVs showed that norovirus GI subtypes were GI-1 (3 strains) and GI-2 (1 strain). Norovirus GII subtypes were GII-4/2006b variant strains (7 strains), GII-2 (1 strain), GII-7 (1 strain) and GII-4/2008 variant strains (2 strains); Sapovirus subtypes were GI-2 (5 strains), GI-1 (4 strains) and GII-1 (1 strain). The prevalence rates of HuCVs were different in seasons and age groups. HuCVs were one of the major pathogens causing acute diarrhea. Both multiple viruses and genotypes of HuCVs were found in the specimens. GII-4/2006b variant and similar strains were identified, probably as the prevalent strains from 2009 to 2010 in Hangzhou, Zhejiang province.