West Nile found in Lake County mosquitoes

The first batch of mosquitoes infected with the West Nile virus has been found in Lake County and more are expected, health officials said Thursday.

Five samples from traps in the southeast part of the county tested positive for the virus, the first confirmed indicators of the presence of the disease.

The samples, which are taken weekly from early June to early October, were collected during the week of Aug. 2. Recent hot and dry weather, which is favored by Culex mosquitoes that carry the virus, could boost those numbers.

"We expect to get more positives and from historical trappings, we expect to get them from all parts of the county," said Mike Adam, senior biologist with the department.

Lake County has about 24 traps and shares information from other traps operated by a mosquito control company.

One mosquito trap, or pool as it is known, tested positive for the virus last year. But as many as 100 did so in previous years, Adam said. The county has not reported a human case of West Nile encephalitis in three or four years.

Adam acknowledged there are "tons and tons" of mosquitoes around but most have been of the floodwater variety, which do not carry the virus. The department will be monitoring the traps closely.

"It can change quite a bit from week to week depending on the weather conditions," he said. "If it remains dry for awhile and hot that will put the advantage to the Culex mosquitoes and increase the risk."

Health officials are urging precautions to prevent mosquito breeding as human West Nile virus cases become more prevalent in the late summer and fall.

One measure is eliminate any standing water, such as in buckets, drums or tires, and keep other receptacles covered. Culex mosquitoes like standing water, Adam said.

"The more stagnant, the stinkier, the better," he said.

Limiting outdoor activity at dusk and other measures can prevent mosquito bites.

While most people infected with the virus show no symptoms, some may become ill three to 15 days after being bitten by an infected mosquito.

Call the West Nile hotline, (847) 377-8300 to report areas of stagnant water or for information regarding the signs and symptoms of West Nile encephalitis or visit the health department at www.lakecountyil.gov.