Investigation of human calicivirus infections for diarrhea patients visiting enteric clinics in Beijing

Objective To investigate the characteristics of human calicivirus infections among diarrhea patients visiting enteric clinics in Beijing.Methods From April 2011 to March 2012,450 diarrhea patients visiting enteric clinics were investigated in Beijing,and fecal specimens of the patients were collected.Human caliciviruses were detected by a reverse transcription polymerase chain reaction (RT-PCR),and then the PCR products were cloned and sequenced.Results A total of 68 positive cases were detected among 450 patients with diarrhea,with the positive rate of 15.11％.Eighteen PCR products were randomly selected for sequencing.Multi-sequence aligements were performed,and phylogenetic tree was constructed.Results showed that 3 strains were sapoviruses and 15 strains were noroviruses,among which 11 strains belonged to norovirus GⅡ/4 (11/18,61.11％),1 strains belonged to norovirus GⅡ/7 (1/18,5.56％),the other 3 strains were not typed (3/18,16.67％) Conclusions Human calicivirus was the important pathogen of diarrhea patients visiting enteric clinics in Beijing,and norovirus GⅡ/4 was the predominant genotype. Key words: Enteric clinics;  Diarrhea;  Human caliciviruses;  Genotype