County positive for West Nile

Health officials are warning people to wear long sleeves and use bug spray if they will be going outside after a potentially deadly virus was found in three-fourths of the state, including Johnson County.

The West Nile virus, which is spread by mosquitoes and birds, has sickened a dozen Indiana residents so far this year, including six people in Marion, Bartholomew, Hendricks, Hamilton and Madison counties. Two Hoosiers have died this year after contracting the disease, according to the Indiana State Department of Health. The state is not releasing where the residents who died had lived.

All but 23 counties have had mosquitoes test positive with the virus, including two batches in Johnson County, according to the Indiana State Department of Health.

“We’re up to 69 counties that have tested positive, but I assure you that West Nile is in every 92 of them,” said Bryan Price, senior vector-borne epidemiologist for the state. “Once you see surrounding counties testing positive for mosquitoes, you can pretty much assume that your county is positive as well.”

Until the weather cools off, residents can still get infected with West Nile virus, Price said. Mosquitoes can still bite and infect residents until the first freeze of the year, or once the temperature drops to about 30 degrees, Price said. The West Nile virus first popped up in Indiana in 2002. Once the virus is detected in a state, it usually does not go away, he said, becase birds and mosquitoes pass it back and forth each spring.

Last year, 10 residents became ill after getting infected with West Nile virus. Since the state already exceeded last year’s number of infected Hoosiers, officials are urging caution to people who are running outside, playing at playgrounds or spending time in their garden this fall.

Price and his three-person team go to each county to get batches of mosquitoes to test for West Nile. His team started collecting mosquitoes in May, but the disease spread the most around July and early August, he said.

The first Hoosier was infected with the disease in the first week of August, said Ken Severson, spokesperson for the Indiana State Department of Health. Residents are still at risk of getting bitten before the end of the year, he said.

The state tracks where the virus has been found and where people have become ill, but those numbers don’t indicate that people in that area are more at risk of getting the virus, Price said.

Whether a person becomes ill with the virus depends on their health and medical history, Price said. Most people who become infected do not show any symptoms, but residents can have anything from a fever to achy muscles to seizures, according to the federal Centers for Disease Control and Prevention. People who work outdoors or play outdoor sports are the most at risk since they are exposed to more mosquitoes.

And the number of mosquitoes that test positive for West Nile in a county also doesn’t reflect how many of the insects are infected there, Price said. Instead, that county may just have a larger sample size than the others. Three counties — Marion, Hamilton and Allen counties — have their own mosquito testing programs, which allows them to test more batches of mosquitoes for the virus.

So even though Marion County has 70 positive samples of mosquitoes, for example, that doesn’t mean the area has more infected mosquitoes, Price said.

State officials are asking Hoosiers to protect themselves since the number of people infected with West Nile virus is up from last year, including two deaths compared with zero last year.

“Any number (of infections) is too many,” Severson said.

To protect yourself when you’re outside, wear longer-sleeved clothing and use insect repellant, Price said. If you like to run or walk at sunrise or sunset, you are more at risk of catching the disease, he said.

“Keep in mind that the primary mosquitoes that spread West Nile are the ones that bite at dusk and dawn,” Price said.

If you have birdbaths, kiddie pools or even overfilled potted plants outside, those can be perfect breeding areas for mosquitoes, Price said. Clean out rain gutters or puddles of water on your property, so mosquitoes don’t congregate there, he said.

By the numbers

So far this year, a dozen of Hoosiers have tested positive for West Nile virus statewide. More than 415 batches of mosquitoes have tested positive for the disease, including two in Johnson County. Here’s a look at how many Hoosiers have caught the disease in recent years:


12 illnesses

2 deaths


10 illnesses

No deaths


23 illnesses

2 deaths


77 illnesses

8 deaths


9 illnesses

1 death


13 illnesses

1 death

Source: Centers for Disease Control and Prevention