Study on the genetic characteristics of enteric viral pathogens of sporadic adult diarrhea in Chaoyang district, Beijing in 2019

Abstract

Objective: To analyze the distribution and genetic characteristics of sporadic adult diarrhea virus in Chaoyang District, Beijing. Methods: Fecal samples from 177 adult patients with sporadic diarrhea were collected from 4 enteric outpatient clinics in Chaoyang District, Beijing from May to December 2019. Nucleic acid detection of Norovirus, Sappovirus, Rotavirus, Enteric Adenovirus and Astrovirus in the samples was performed by real-time quantitative PCR. The positive samples were amplified by RT-PCR/PCR and sequenced. The phylogenetic analysis was performed by neighbor-Joining (NJ) methods of Mega 6.0 software. Results: There were 60 of 177 (33.90%) adult sporadic diarrhea samples positive for enteric viral pathogens. Among them, 47 cases were infected with single virus, including 29 cases of Norovirus, 9 cases of Sappovirus, 8 cases of Astrovirus and 1 case of Enteric Adenovirus, in addition with 13 cases of multiple infections. None of rotavirus was detected. Partial sequences were successfully obtained for analysis, including 16 cases of GI Norovirus (7 subtypes and GI.3[P13] predominant), 10 cases of GII Norovirus (5 subtypes and GII.6[P7] predominant), 12 cases of Sappovirus (4 subtypes and GI.2 predominant), and 7 cases of Astrovirus (2 subtypes and AST-1 predominant). Conclusion: Norovirus, Astrovirus and Sappovirus are main pathogens among sporadic adult diarrhea in Beijing in 2019, and and different pathogenic gene subtypes show diverse characteristics.