University of Wisconsin–Madison

Mosquitoes and disease in Wisconsin

Mosquitoes can transmit several viruses that can cause human disease.  In Wisconsin, these include West Nile virus, La Crosse virus, and Jamestown Canyon virus.  We also see cases of disease that are imported (people who travel outside the state and pick up an infection somewhere else).  In this section, I will provide information about disease and vectors. 

Recently, the Zika virus has been in the news because of epidemics in Latin America that are associated with microcephaly.  Zika virus is known to be transmitted by 2 species of mosquito that have not been found in Wisconsin.  These are Aedes aegypti (the yellow fever mosquito) and Aedes albopictus (the Asian tiger mosquito).  The Asian tiger mosquito was discovered in Wisconsin in 2017 but tests with eggs placed in the environment suggest that they did not survive the winter.  The risk of Zika transmission by local and abundant mosquitoes appears to be very low.