State health officials are urging Indiana residents to protect themselves from mosquito bites following the identification of the first West Nile virus case of 2021 in a Lake County resident and the detection of West Nile virus in mosquitoes in multiple counties.

As of today, a total of 83 mosquito pools positive for West Nile virus have been detected in Allen, Clark, Daviess, Elkhart, Floyd, Gibson, Hamilton, Jennings, Lake, Marion, Martin, Pike, Scott, Steuben, St. Joseph, Vanderburgh and Vigo counties.

“Mosquitoes are still active even in cooler fall weather,” said State Health Commissioner Kristina Box, M.D., FACOG. “Hoosiers in every county should take precautions against mosquito-borne diseases until the first hard freeze.”

The Indiana Department of Health expects to continue to see additional West Nile virus activity as the mosquito season progresses. Residents across the state should take proper precautions to reduce their risk of exposure. Residents of northern Indiana should also be aware of ongoing increased risk for Eastern equine encephalitis (triple-E) virus, which caused regional outbreaks in the United States in 2019 and 2020. 

State health officials recommend the following measures to prevent mosquito-borne diseases:

  • Avoid being outdoors when mosquitoes are active (especially late afternoon, dusk to dawn and early morning);
  • Apply an EPA-registered insect repellent containing DEET, picaridin, IR3535, oil of lemon eucalyptus or para-menthane-diol to clothes and exposed skin;
  • Cover exposed skin by wearing a hat, long sleeves and long pants in places where mosquitoes are especially active, such as wooded areas;
  • Install or repair screens on windows and doors to keep mosquitoes out of the home. 

Even a container as small as a bottle cap can become a mosquito breeding site, so residents should take the following steps to eliminate potential breeding sites:

  • Discard old tires, tin cans, ceramic pots or other containers that can hold water;
  • Repair failed septic systems;
  • Drill holes in the bottom of recycling containers left outdoors;
  • Keep grass cut short and shrubbery trimmed;
  • Clean clogged roof gutters, particularly if leaves tend to plug up the drains;
  • Frequently replace the water in pet bowls;
  • Flush ornamental fountains and birdbaths periodically; and,
  • Aerate ornamental pools, or stock them with predatory fish. 

West Nile virus can cause West Nile fever, a mild form of the illness, which can include fever, headache, body aches, swollen lymph glands or a rash. Some people will develop a more severe form of the disease affecting the nervous system, including inflammation in the brain and spinal cord, muscle paralysis, or even death. People older than 60 years are at higher risk of severe West Nile virus disease. People who think they may have West Nile virus should see their healthcare providers.  

To see the latest results of the state’s mosquito surveillance, go to

To learn more about West Nile virus, visit

To learn more about Eastern equine encephalitis virus, visit