Epidemiological and genetic characteristics of human astrovirus in Futian district, Shenzhen, 2013-2015

Objective To investigate the epidemiological and genetic characteristics of human astorvirus (HAstV) infections in Futian district, Shenzhen. Methods A total of 1 625 stool samples were collected from patients with suspected diarrhea in Futian district, Shenzhen from January 2013 to December 2015. The HAstV RNA was detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR), and the ORF2 of HAstV in positive samples was amplified and sequenced by RT-PCR with primer set of Mon269/Mon270, followed by phylogenetic analysis. Results From January 2013 to December 2015, the overall detection rate of HAstV was 2.03% (33/1 625), while the annual detection rates were 1.84% (12/653), 1.31% (7/535) and 3.20% (14/437), respectively. The detection rate of HAstV was 2.27% (21/925) among males and 1.71% (12/700) among females. There was no significant difference in the detection rate between male and female (x2=0.62, P=0.431). HAstV was detected in all age groups, while the detection rate was significantly lower in age group < 1 year old (1.69%, 11/650). The detection rate was the highest in January (5.59%, 8/143), and was the lowest in July (no case was detected). Thirty-three positive samples were sequenced and analyzed, HAstV-1, HAstV-4, HAstV-5 and HAstV-2 were detected in 15, 7, 4, 1 sample(s), respectively, of which HAstV-1 was the predominant strain. Conclusions HAstV was a pathogen causing viral diarrhea in Futian district. HAstV-1 was the predominant strain, while other genotypes also existed. Key words: Astrovirus; Reverse-transcriptase polymerase chain reaction; Sequence analysis; Epidemiologic studies