Hamilton County records first human case of West Nile Virus

HAMILTON COUNTY, Ind. — A resident in Hamilton County has tested positive for West Nile Virus, becoming the county’s first human case of the mosquito-borne disease in 2025.

According to the Hamilton County Health Department, this marks the second human case to be reported in Indiana this summer. In July, the virus was reported for the first time this year in a resident of Vanderburgh County.

“Most people infected with West Nile virus have no symptoms or only mild flu-like symptoms which can include fever, headache, body aches, joint pain, vomiting, diarrhea, or a rash,” Hamilton County Health Officer Charles Harris said. “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.”

The health department said the virus can be severe for individuals 60 years old or older or those with already weakened immune systems. According to the release, Hamilton County discovered its first West Nile Virus positive case in a mosquito sample in June. In response, the county has since carried out mosquito spraying and increased surveillance to reduce the number of mosquitoes.

A total of 11 West Nile Virus cases were recorded in the Hoosier state last year.

Most people who contract the virus will experience no symptoms or only develop minor flu-like symptoms. A small number of people can develop a more dangerous form of the disease that can go on to affect the nervous system, induce inflammation in the brain and spinal cord, and lead to muscle paralysis or death.

Common symptoms include:

• High fever
• Severe headache
• Neck stiffness
• Muscle weakness or paralysis
• Nausea or vomiting
• Sore joints
• Confusion

Hoosiers can follow these recommended steps to reduce their risk:

• Drain or discard old tires or other containers that can hold water
• Repair septic systems
• Drill holes in the bottom of containers that are left outside
• Clean clogged roof gutters
• Keep your grass short and shrubs trimmed
• Frequently replace the water in pet bowls
• Install or repair window screens and doors to keep mosquitoes out of your home

More information can be found by visiting the Indiana Mosquito-Borne Activity Dashboard.