Investigation of mosquitoes and arboviruses in Delingha area in Qinghai, 2013

Objective To investigate the species and distributions of mosquitoes and arboviruses in Delinha of Qinghai province. Methods Mosquito samples were collected from Delinha. The virus isolation from these samples was conducted by using C6/36, BHK-21 and Vero cells, and the isolates were identified with molecular biological methods. Results A total of 6050 mosquito samples were collected from in 2013, including 5600 Aedes flavidorsalis (92.6%) and 450 Aedes caspius (7.4%). All the mosquitoes were divided into batches to be inoculated with C6/36, BHK-21 and Vero cells for virus isolation. No pathogenic changes and virus genes were detected in all the mosquito samples inoculated with BHK-21 and Vero cells, but Liaoning virus(LNV)was detected in 32 batches of mosquitoes inoculated with C6/36 cells, i.e. supernate and grinding fluid, including 27 batches of Aedes flavidorsalis and 5 batches of Aedes caspius (15.6%). Phylogenetic analysis revealed that the LNV isolated from Delingha was in the same evolutionary branch with LNV isolated in Xinjiang. Conclusion Aedes flavidorsalis was predominant mosquito specie in Delingha in 2013. The LNV infection rates were high in both Aedes flavidorsalis and Aedes caspius. This was the first time to detect LNV in Delingha.