West Nile, one of two confirmed mosquito viruses in Saginaw County in 2019

SAGINAW, MI – Two mosquito-transmitted viruses have been found in mosquitoes in Saginaw County that were tested in May.

As the weather warms up, the Saginaw County Mosquito Control Commission wants to encourage residents to use an insect repellent and take other precautions.

In May, the commission used systematic surveillance for mosquito-borne diseases and found evidence of West Nile virus and Jamestown Canyon virus among mosquitoes in Saginaw County.

Detection of West Nile was found in Culex mosquitoes, while Jamestown was found in Aedes mosquitoes. According to the commission's release, they are the first cases of detection of viral activity transmitted by mosquitoes in Saginaw County in 2019.

Commission officials said that early detection of mosquito-borne viruses, although very low among mosquito populations, reminds that mosquitoes can be more than a nuisance and that precautions must be taken to avoid mosquito bites.

Surveillance of mosquito-borne viruses will continue until the end of September by analyzing some mosquito samples for the presence of five viruses associated with the Michigan mosquito population. Viruses include West Nile, Jamestown Canyon, La Crosse encephalitis, St. Louis encephalitis, and Eastern equine encephalitis.

Surveillance of West Nile virus also includes testing of crows and dead blue jays. All areas of the county with high levels of viral activity transmitted by mosquitoes will be subject to extensive control efforts to reduce adult mosquito and larval populations.

West Nile virus has been detected annually in Saginaw County since its introduction in 2002 and is known to be primarily transmitted by Culex mosquitoes. The Jamestown Canyon virus, a mosquito-transmitted re-emerging virus, can be detected in many species of mosquitoes known to bite humans.

Human infections are rarely diagnosed because the majority of infections cause no symptoms (asymptomatic). Symptoms may include the sudden onset of a flu-like illness accompanied by fever. According to the press release, serious cases, although rare, can develop neurological symptoms such as meningitis or encephalitis requiring hospitalization.

Citizens are encouraged to take appropriate measures to avoid mosquitoes and are urged to contact the Board's office at (989) 755-5751 if they notice a crow or blue jay that has been dead for less than 24 hours.