Detection of Japanese encephalitis virus and Tembusu virus in mosquito specimens from Daozhen county,Guizhou province
Objective To understand the situation of arboviruses carried by mosquito specimens in Daozhen county,Guizhou province.Methods In July 2023,mosquito specimens were collected in Daozhen county,Guizhou province,using photocatalytic mosquito trap method.Reverse transcription polymerase chain reaction(RT-PCR)technology was used to detect the types of viruses carried by mosquitoes,and phylogenetic trees were constructed using the neighbor-joining method to analyze the phylogenetic position of the detected viruses.Results A total of 5 313 mosquito specimens belonging to 2 genera and 2 species were collected in Daozhen county,Guizhou province,including 3 953 Culex tritaeniorhynchus,1 355 Armigeres subalbatus,and 5 other mosquito species.The specimens were divided into 54 batches according to their species for grinding,nucleic acid extraction,and testing.Among them,6 batches of Cx.tritaeniorhynchus specimens tested positive for flavivirus genus using universal primers,and further identification revealed that 5 batches were positive for Japanese encephalitis virus(JEV)nucleic acid,and 1 batch was positive for Tembusu virus(TMUV)nucleic acid.Phylogenetic analysis showed that the detected JEV strains were all genotype Ⅰ and fell within the same evolutionary branch;the detected TMUV was located on the third branch of the evolutionary tree,with the main host source of the strains on this branch being mosquitoes.Conclusions In the mosquito specimens collected in Daozhen county,Guizhou province in 2023,genotype Ⅰ JEV and TMUV were detected,with TMUV being detected for the first time in mosquitoes in Guizhou province.It is essential to enhance the surveillance of JEV and TMUV to mitigate the potential public health risks they pose.