(Des Moines, Iowa) – The Iowa Department of Health and Human Services (HHS) reports the first West Nile virus (WNV) infection identified in 2025. The individual is a middle-aged adult (41-60 years) from northern Iowa and the infection was confirmed through a test at the State Hygienic Lab.

Warm summer weather means Iowans are spending more time outside which increases the risk of mosquito bites. Bites from infected mosquitos are the primary method in which humans are infected with the virus. Mosquitoes across Iowa are testing positive for WNV, signaling risk statewide.

For the best protection against the virus, Iowans should use an insect repellant with DEET, picaridin, oil of lemon eucalyptus, para-menthane-diol, 2-undecanone, or IR3535. Insect repellent lowers the risk of mosquito bites.

• Always read and follow label directions. Consult with a health care provider if you have questions when using these types of products on children.

• Oil of lemon eucalyptus and para-menthane-diol should not be used on children younger than 3 years, and DEET should not be used on infants younger than 2 months.

• If you are also using sunscreen, apply sunscreen first and insect repellent second.

“We want Iowans to enjoy the outdoors, but also to protect themselves from mosquito bites, which can spread illnesses like West Nile Virus,” said Dr. Robert Kruse, Iowa’s State Medical Director. “To stay safe, we recommend using bug spray and make sure your windows in your home have screens.”

Additional steps Iowans can take to protect themselves include:

• Wear long-sleeved shirts, pants, shoes, and socks outdoors when possible.

• Look for standing water in buckets, cans, pool covers, used tires, pet water dishes, and other areas water may collect.

• Clear standing water from around your home where mosquitos reproduce.

Iowans infected with WNV may not experience any signs or symptoms of the virus. Some people experience minor symptoms like fever and mild headache. Others, however, can develop serious symptoms such as a high fever, headache, disorientation, and muscle weakness.

People who experience mild signs and symptoms of a WNV infection generally recover on their own, but illness that includes a severe headache, disorientation, or sudden weakness require immediate medical attention.

In 2024, 21 Iowans were diagnosed with West Nile virus, with one death.

For more information, visit the West Nile Virus page.