Breaking News Bar
updated: 6/3/2013 5:32 PM

West Nile virus found in local mosquitoes

Success - Article sent! close
  • It's back -- a sampling of mosquitoes collected in Hillside tested positive for West Nile virus.

    It's back -- a sampling of mosquitoes collected in Hillside tested positive for West Nile virus.
    Daily Herald File Photo


Thumbs down -- the first batch of mosquitoes carrying the West Nile virus was detected in Cook County, Illinois Department of Public Health officials announced.

Thumbs up -- all the cold, rainy weather is a discouraging climate for the Culex mosquitoes that carry the virus.

But the constant precipitation is exactly what floodwater mosquitoes need to thrive, so once it warms up, expect a bumper crop, University of Illinois Extension entomologist Philip Nixon predicts.

"They're likely to come out fairly numerously," he said.

Concerning West Nile virus, the Des Plaines Valley Mosquito Abatement District gathered a positive mosquito sample May 21, which was confirmed by the state Monday. No human cases have been reported this year so far.

The drought and heat of 2012 collaborated for one of the worst West Nile virus seasons in Illinois since 2002 with 290 cases reported and 12 fatalities.

This spring, "nuisance" mosquitoes are starting to make life miserable although they haven't appeared as early as in previous years.

The region caught a slight break because of the unusual pattern of hot and cool weather in May, Nixon said. The eggs of floodwater or nuisance mosquitoes that don't carry West Nile virus need warm water to hatch and the constant rainfall and temperatures in the 60s work against that, he noted.

However, it's inevitable that hot weather will prevail and with all the rainfall, we're in for a floodwater mosquito beatdown.

National Weather Service meteorologist Tim Seeley said temperatures should stay in the 60s and 70s all week with showers expected. "Hot and dry does not appear to be in our immediate future," he said.

Then, from June 8 to 12, there's a 40 percent to 50 percent chance of temperatures below normal with precipitation forecast to be 40 percent above normal.

When it inevitably warms up, however, Nixon reminded homeowners to remove standing water on their properties that's a perfect breeding ground for Culex mosquitoes.

"This is a mosquito that picks water that is putrid ... when we get periodic rains, the water freshens up too much for it to like it. It lays eggs in clogged gutters and old tires. It does its best in hot, dry weather," he explained.

And while floodwater mosquitoes can travel more than 30 miles from their origins, Culex mosquitoes stay close to home.

"How well you and your neighbors keep the standing water from sitting around makes a big difference in how many mosquitoes are around to transmit the disease to you," Nixon said.

To avoid contracting West Nile virus, officials offer the following tips.

• Use bug spray when outside.

• Keep indoors between dusk and dawn when possible.

• Wear long-sleeved shirts and pants if you're outside when it's dark.

• Eliminate standing water in your yard. Water that stagnates for more than three days can be a breeding ground for mosquitoes.

• Keep screens in windows and doors tightfitting.

The virus, which can cause fever, headache and body aches, usually strikes one out of five people bitten by an infected bug. In some cases, West Nile symptoms can worsen, leading to meningitis, encephalitis and possibly death.

Article Comments ()
Guidelines: Keep it civil and on topic; no profanity, vulgarity, slurs or personal attacks. People who harass others or joke about tragedies will be blocked. If a comment violates these standards or our terms of service, click the X in the upper right corner of the comment box. To find our more, read our FAQ.