Prevent West Nile: Say No To Mosquitoes This Summer


West Nile virus is…

  • Carried by mosquitoes. It is the most common mosquito-borne illness in the U.S. 1 out of 5 people who are infected show symptoms, and 1 out of 150 people develop a serious and sometimes fatal illness.

    monitoring for mosquitoes

  • Now considered endemic in Dane County. West Nile virus has been regularly found (endemic) in Dane County since 2003. Before 2020, we tested dead birds for West Nile because birds can also get the virus. 

  • Relatively rare in Wisconsin. An average of 20 people in Wisconsin get West Nile every year. Some years are higher and some are lower.
  • Most commonly spread by the Culex species of mosquito. To help curb the spread of Culex, we test public sites and treat the ones with high levels of this type of larvae.

What makes mosquitoes worse some years and better others?

  • Many mosquitoes breed in water and they need warmer temperatures in order for eggs to hatch. Seasonal variations in rain and temperature can affect mosquito populations.
  • As Wisconsin gets warmer due to climate change, we can expect our summers to trend toward being more and more mosquito-filled, and more chances for people to catch mosquito-related diseases.

What mosquitoes are in my area?

  • We test ditches, retention ponds, and other water sources for mosquito larvae to prevent mosquito-related illnesses, most notably West Nile virus.

  • You can see 2022’s testing results mapped out on our website.

  • Even if you don’t live near a high-mosquito site, you could still get bitten!

How do I prevent mosquito bites?

  • Mosquitoes like to lay eggs in standing water. They don’t need a lot, so be sure to keep things dry. Drain any standing water in your outdoor living areas. You might see water accumulating in clogged gutters, air conditioners, tarps, wheelbarrows, plant debris, flower pots, pet dishes, or birdbaths.

  • Use insect repellents on skin and clothing before heading outdoors during mosquito season (May-September).

  • Wear long-sleeved shirts, pants, socks, and shoes outside during peak mosquito activity hours.

Learn more on the Department of Health Services website.

This content is free for use with credit to Public Health Madison & Dane County .

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