No tropical viruses have been detected in the mosquito population in the Swiss canton of Basel-City. +Get the most important news from Switzerland in your inbox The cantonal laboratory has found no trace of dengue, chikungunya, Zika or West Nile viruses in an investigation, it announced on Wednesday. The risk of local transmission of these pathogens by the tiger mosquito can therefore still be considered low. Only the Usutu virus, which is transmitted by the native mosquito species and mainly infects birds, has been detected. The cantonal laboratory analysed 5,674 mosquitoes last year. It collected mosquitoes with traps at ten locations in Basel, Riehen and Allschwil every week between August and November. Of the insects caught, native Culex mosquitoes made up the vast majority (97.6%). These can also transmit diseases, mainly the West Nile and Usutu viruses. In 2022, Culex mosquitoes with West Nile virus were detected in Ticino for the first time. Usutu virus, on the other hand ...
