Xiuyan Xu1,2, Jingxia Cheng3, Shihong Fu2, Qinyan Wang1,2, Jing Wang2, Xiaoqing Lu1, Xiaodong Tian3, Jianshu Cheng4, Shuqing Ni4, Ying He2, Fan Li2, Songtao Xu2, Huanyu Wang2, Bin Wang5, Guodong Liang2. 1. School of Public Health, Qingdao University, Qingdao, China. 2. State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China. 3. Shanxi Province Center for Disease Control and Prevention, Taiyuan, China. 4. Wuxiang County Center for Disease Control and Prevention, Wuxiang, China. 5. School of Basic Medicine, Qingdao University, Qingdao, China.
Abstract
Background: Wuxiang virus was isolated from sandfly specimens collected in Wuxiang County, Shanxi Province, China in 2018, representing the first reported isolation of sandfly-borne virus from sandflies collected in a natural environment in China. The local sandfly density, seasonal fluctuations, and temporal and spatial distributions of the virus in Wuxiang County remain unclear. Materials and Methods: Four fixed sandfly collection sites were set up in Wuxiang County and sandfly specimens were collected continuously from June to August 2019. All sandfly specimens were subjected to viral isolation and molecular biological analysis. Results: The data on sandfly specimens collected in Wuxiang County from June to August 2019 showed a significant difference in the density of sandflies between June 26 and August 16 (p < 0.05). No statistical difference was found in sandfly density among collection sites (p > 0.05). A total of 33 virus isolates causing cytopathic effects in mammalian (BHK-21) cells were obtained from 7466 sandflies (91 pools) collected from June to August 2019. The results of molecular genetic evolution analysis of the nucleotide sequence of these isolates showed that the L and S genes (encoding NS and N proteins) of the 33 viruses isolated in 2019 are in the same evolutionary branch as the previously isolated Wuxiang virus. No significant difference was found in the virus isolation rate (the pool isolation rate of virus) among sandflies collected at different times from June to August (p > 0.05). The virus isolation rate of sandflies collected at different collection sites showed a statistically significant difference (p < 0.05). Conclusions: The results of this study suggest that the Wuxiang virus is a stable viral population in local sandflies. Strengthened research into Wuxiang virus infection of humans and animals and clarification of the public health hazards posed by Wuxiang virus to both humans and animals are urgently needed.
Background: Wuxiang virus was isolated from sandfly specimens collected in Wuxiang County, Shanxi Province, China in 2018, representing the first reported isolation of sandfly-borne virus from sandflies collected in a natural environment in China. The local sandfly density, seasonal fluctuations, and temporal and spatial distributions of the virus in Wuxiang County remain unclear. Materials and Methods: Four fixed sandfly collection sites were set up in Wuxiang County and sandfly specimens were collected continuously from June to August 2019. All sandfly specimens were subjected to viral isolation and molecular biological analysis. Results: The data on sandfly specimens collected in Wuxiang County from June to August 2019 showed a significant difference in the density of sandflies between June 26 and August 16 (p < 0.05). No statistical difference was found in sandfly density among collection sites (p > 0.05). A total of 33 virus isolates causing cytopathic effects in mammalian (BHK-21) cells were obtained from 7466 sandflies (91 pools) collected from June to August 2019. The results of molecular genetic evolution analysis of the nucleotide sequence of these isolates showed that the L and S genes (encoding NS and N proteins) of the 33 viruses isolated in 2019 are in the same evolutionary branch as the previously isolated Wuxiang virus. No significant difference was found in the virus isolation rate (the pool isolation rate of virus) among sandflies collected at different times from June to August (p > 0.05). The virus isolation rate of sandflies collected at different collection sites showed a statistically significant difference (p < 0.05). Conclusions: The results of this study suggest that the Wuxiang virus is a stable viral population in local sandflies. Strengthened research into Wuxiang virus infection of humans and animals and clarification of the public health hazards posed by Wuxiang virus to both humans and animals are urgently needed.