West Nile Virus

West Nile virus (WNV) is the most common mosquito-borne disease in Kansas and the United States. Several species of mosquitoes are responsible for transmission of arboviruses, but Culex species are the primary vector in Kansas and the United States. The risk of acquiring WNV infection depends on various factors including:

  • Time of year
  • Number and location of infected mosquitoes
  • Number of days with sufficient heat

Warm temperatures increase the rate of mosquito larvae development, which increases the mosquito population size. The risk of WNV transmission is lower in the spring, but rises through the early and midsummer months, and usually reaches peak transmission during July, August, and September.

West Nile Virus Weekly Risk Assessment Map & Data Dashboard

This map contains a weekly snapshot of the risk of being bitten by a mosquito carrying West Nile Virus during peak season, which is July through September. The data will be updated weekly on Friday. Learn what the risk levels mean and what you can do to prevent mosquito bites in the section below the map.  View the West Nile Virus Data Dashboard.

Risk Assessment  - What It Means & What You Can Do

  1. High
  2. Moderate
  3. Low
  4. Minimal

High Risk Week

High risk means that you are at a high risk of being bitten by a mosquito that could be carrying West Nile, based on a high number of mosquitoes identified and a high number of historical human cases.  Do the following to prevent mosquito bites:

  • People over 50 or people who are immunocompromised may want to adjust outdoor activity to avoid peak mosquito hours, which is from dusk to dawn
  • Wear mosquito repellent
  • Wear long sleeves and long pants when weather permits
  • Use mosquito netting on baby carriages and playpens
  • Dump standing water twice weekly

Mosquito Bite Prevention

  1. Drain
  2. Dress
  3. DEET

Drain Standing Water

Eliminate standing water where mosquitoes live and breed.

  • Empty standing water from tarps, old tires, buckets, and other places where rainwater collects. Use larvicide in low-lying areas where water cannot be removed.

  • Refresh water for bird baths, pet bowls, and wading pools at least every three days.

Surveillance & Risk Assessment

Learn more about surveillance and risk assessment, and find resources and contact information for KDHE's Epidemiology team.

  1. Surveillance
  2. Risk
  3. Resources
  4. Reports
  5. Contact

Mosquito Surveillance

In 2017, the Kansas Department of Health and Environment, with funding from the Centers of Disease Control and Prevention, expanded the mosquito surveillance from 1 to 3 counties (Reno, Sedgwick, and Shawnee). These counties will continue to participate in surveillance in 2022. In addition, we collect mosquito surveillance data from 3 additional partners throughout the state. Mosquito surveillance began on June 27, 2022 and will continue through mid-October 2022.