The bite of a mosquito can pack more than itchy poison, which is why local health officials are attacking them at the source — standing water.

Since 2002, nearly 500 Hoosiers have been infected with West Nile virus, an illness transmitted by the pesky vectors so common during Indiana summers. To counter the threat, the Cass County Health Department is using state and federal grants to chemically treat breeding sites and educate the public.

Mosquitoes tend to reproduce in shaded, stagnant water. Rivers and streams move too fast, and ponds generally get too much wind and sun. Some of their favorite spots are old tires, clogged gutters, wading pools and buckets, said Rob McLaughlin, an environmental health specialist with the county health department.

Health officials want to head them off there.

“We want to treat them before they reach the adult stage,” McLaughlin said. “The key is getting our chemicals out early and getting these spots to keep from breeding, eliminating at least some percentage of our mosquito population will help everything.”

The task of tracking and treating the hundreds of mosquito breeding grounds is the responsibility of summer intern Justin Vixler, a Logansport resident and University of Indianapolis student. He has two treatment options: to stunt the growth of mosquito larvae or kill them by deprivation.

Stunting lasts 90 days and means fewer site visits, while starving the larvae of oxygen lasts only two weeks. Considering how quickly mosquitoes can reproduce — about seven days — the residual is used where water stands for extended periods. Vixler applies the deadlier method to flood waters.

Mosquitoes tend to stay close to their breeding site. That’s a good reason to join with neighbors to eliminate standing water by cleaning gutters and dumping buckets, McLaughlin said.

Health department officials find out about breeding sites through patrolling the county and hearing from the public, something they would like more of.

“We need a lot more cooperation from the public to make a bigger dent in the mosquito population,” McLaughlin said. “There’s only so many spots you can see and get to from the road. The more information the public has about our program, the more phone calls we can get, the more invitations we can get.”

So, why should people care about the population of an insect? The main answer is because these blood-sucking insects spread disease.

“West Nile is still a big concern,” McLaughlin said.

The virus, which can be deadly, is still as much a concern now as in 2002 and 2003 when cases in Indiana peaked, he said.

State health officials say in 2002 Indiana had wet weather conditions in the spring, including flooding in parts of the state, followed by a hot, dry summer. In that year, the state had the most human cases of West Nile virus to date — 293. Similar weather conditions occurred this year, said Dr. James Howell, state epidemiologist at the Indiana State Department of Health.

“We are starting to see the virus show up in mosquito populations,” Howell said.

West Nile has been identified in Marion County. Howell suspects it’s in other counties as well.

A Cass County resident recently showed symptoms of West Nile virus. Testing showed he had been infected, but it was an old case. The virus reportedly had lingered.

“We don’t have it in the county as far as we know, but are still especially concerned given the illness this person got in relation to a mosquito bite,” McLaughlin said.

Results of on-site testing by the state came up negative.

The potential exists for an explosion of the mosquito population and the spread of the virus, Howell said. In previous years, late July is when state officials began seeing increasing number of positive mosquitoes.

“So, now is the time for people to really pay attention to good mosquito control,” Howell said.

Mosquitoes are most active from dusk till dawn. During that time, people either avoid outdoor activities or wear repellent containing DEET and protective clothing such as jeans and a long-sleeved shirt.

“Just because you’re in your yard doesn’t mean you’re safe,” Howell said. “This is when you are probably at biggest risk.”

McLaughlin also suggests keeping grass cut short. Although that is not where mosquitoes breed, they do tend rest in weeds and overgrowth during the day, when they are not as active.

Kevin Lilly can be reached at (574) 732-5117, or via e-mail at kevin.lilly@pharostribune.com



Reducing risk

Tips on eliminating mosquito breeding grounds:

• Dispose of old tires, tin cans, plastic containers, ceramic pots or other unused 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 the drains.

• Aerate ornamental pools, or stock them with predatory fish.

Source: Indiana Department of Health



Got bugs?

• To have the Cass County Health Department treat suspected mosquito breeding grounds at no charge, call Environmental Specialist Rob McLaughlin at (574) 753-7762.