Molecular epidemiology of astrovirus in adults with diarrhea in Beijing

Objective To investigate the molecular epidemiological characteristics of human astrovirus (HAstV) in adults with diarrhea in Beijing, China. Methods A total of 519 fecal specimens from patients ≥14 years of age with acute gastroenteritis were collected with relevant clinical data in Xuanwu Hospital Capital Medical University from August 2008 to July 2009. HAstV was detected by RT-PCR, positive PCR products were sequenced and phylogenetic analyses were carried out. Results The total positive rate of HAstV was 6.7% (35/519), of which 15 were male, the positive rate was 5.6% (15/270); the female was 20 cases, the positive rate was 8.0% (20/249). There was no statistically significant difference (x2=1.26, P=0.261). The seasonal peak occurred in October (17.5%, 14/80) and the highest detection rate was in the age group of ≥ 60 (8.9%, 7/79). Positive specimens were sequenced and 24 sequences were obtained. Phylogenetic analysis showed that seventeen (70.8%, 17/24) strains were classic HAstV-1, four strains were HAstV-2, one strain was HAstV-4, one strain was HAstV-5 and one strain was HAstV-8. Conclusions HAstV is one of the important pathogens causing diarrhea in adults in Beijing and classic HAstV-1 is the predominant strain. Key words: Astrovirus; Diarrhea; Genotype; Epidemiology