Investigations Of Mosquito Species And Arbovirus In The Part Areas Of Chuxiong Prefecture, Yunnan

Objective To investigate mosquito species and arbovirus in Yuanmou, Wuding and Shuangbai of Chuxiong prefecture, Yunnan, providing effective evidences with local arbovirus borne infectious diseases control. Methods In Yuanmou, Wuding and Shuangbai of Chuxiong prefecture, according to various latitudes, longitudes and attitudes each county chose 2 representative sites as mosquito investigations, and collecting the related geographic data by GPS.(1) Mosquito adult collections were used by lamp-traps in resident, cattle and pig house overnight and by double-bednets in the bamboo forest around villages from 08:00 am to 20:00pm, larvae were collected in the different breeding sites around villages; all collected adult and IV-star larvae were identified by local mosquito compositions and diversity analysis.(2) Mosquito adults were captured in the field sites and classified, counted, registered, freezed in liquid Nitrogen, in the laboratory by their grinding, the supernatant were inoculated C6/36 cells to isolate the virus, the virus were identified by RT-PCR and other methods. Results(1)Total of 12384 individuals were collected from 15 species in 5 Genus by lamp-traps, of those Culex tritaeniorhynchus and Culex pipiens quinguefasciatus as Japanese encephalitis vectors belonged to local predominant species, their percentages were 59.95%(7424/12384) and 10.90%(1350/12384) of total collected mosquitoes respectively; as malaria vectors, Anopheles sinensis and Anopheles minimus were local predominant species, their percentages were 19.31%(2391/12384) and 4.13%(511/12384) of total collected mosquitoes respectively; in 6 field sites of 3 counties, their species richness were lower, and their diversity indexes, Pielou evenness indexes and Ecological dominances were almost similar; total of 327 individuals were collected from 11 species in 4 Genus by double-bednets, of those Aedes albopictus as dengue vector were local predominant species(19.88%), the next were Aedes Craggi(18.35%)and Armigere.subalbatus(14.07%); total of 238 IV-star larvae were collected from 18 species in 6 Genus, of those Culex tritaeniorhynchus was the highest.(2)Total 29 cytopathic patches were found from 116 patches by C6/36 cells and BHK21 cells isolation, of those 4 arboviruses were identified from Cx.tritaeniorhynchus,Cx.pipiens quinguefasciatus, Culex theileri and An.sinensis by Rt-PCR i.e. Banna virus(BAV), Totivirus(TOV), Japanese encephalitis virus(JEV) and Nam Dinh virus(NDi V); their rates of positive patches of JEV、BAV、TOV and NDi V in Cx. Tritaeniorhynchus were 1.87%、11.32%、3.77% and 9.43% respectively, that of NDi V in Cx.theileri was 25%, those of BAV and NDi V in Cx. pipiens quinguefasciatus were 20% and 33.34% respectively, those of BAV and NDi V in An.sinensis were 50% and 7.5% respectively. Conclusions The species richness was low in 3 counties of Chuxiong prefecture with 15 species of 5 Genus, both Cx. Tritaeniorhynchus and Cx. pipiens quinguefasciatus as Japanese encephalitis vectors, An.sinensis and An.minimus as malaria vectors, as well as dengue fever vector Ae. albopictus belonged to local predominant species; total of 4 arbovirus were isolated and identified from 4 mosquito species, and their rates of positive patches of JEV、BAV、TOV and NDi V in Cx. Tritaeniorhynchus were 1.87%、11.32%、3.77% and 9.43% respectively, that of NDi V in Cx.theileri was 25%, those of BAV and NDi V in Cx. pipiens quinguefasciatus were 20% and 33.34% respectively, those of BAV and NDi V in An.sinensis were 50% and 7.5% respectively. Above results suggested that related departments would be strengthen to study the relationship between BAV and disease transmission.