Molecular characterization of classic human astrovirus in eastern China, as revealed by environmental sewage surveillance

AimsTo determine the molecular epidemiology of classic human astrovirus (HAstVs) in sewage and supplement limited clinical data in China. Methods and ResultsClassic HAstVs in domestic sewage in Shandong Province, eastern China in 2014 were analysed in a total of 23 sewage samples. After viral concentration, reverse transcription-PCR (RT-PCR), cloning and sequencing, all samples were positive for classic HAstVs and 115 sequences were obtained, belonging to five different genotypes (HAstV-1,-2, -3, -4 and -5). Of these, HAstV-4 (313%, 36/115), -5 (243%, 28/115) were detected with higher rates than HAstV-1 (217%, 25/115), followed by HAstV-2 (174%, 20/115) and -3 (52%, 6/115). High identities were observed within all genotypes in 2014. Interestingly, recombination events were identified at a high frequency (122%, 14/115), and variable combinations were obtained. ConclusionsThis study suggests that multiple HAstVs genotypes co-circulated with high prevalence in local population during surveillance period. Significance and Impact of the StudyThe results demonstrate that sewage analysis is a useful approach in surveillance HAstVs in the context of limited clinical data.