Birds with West Nile virus found in Wisconsin

MADISON, Wisconsin (CNN) -- Two crows found in Milwaukee County have tested positive for the West Nile virus, the first time the virus has been found in the state, officials said Friday.

The Wisconsin Division of Public Health made the announcement based on preliminary test results; confirmatory tests are pending.

"These are the first two birds to test positive for West Nile virus in Wisconsin," said Dr. Jeffrey P. Davis, chief medical officer and state epidemiologist for communicable diseases in the state's public health division.

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There have been no human cases of West Nile virus infection detected in Wisconsin. "The risk to Wisconsin residents remains low; however, personal measures to protect against mosquito bites are warranted," Davis said.

The department will beef up surveillance for suspected human cases of West Nile virus infection throughout the state, and will increase the testing of sick and dead crows and blue jays for West Nile virus statewide, he added.

As in other areas where the virus has been found, Wisconsin residents are urged to reduce their risk of being bitten by mosquitoes by limiting outdoor activities between dusk and dawn; wearing long pants and long-sleeved shirts when outside; using mosquito repellent; eliminating stagnant water from containers such as old tires or birdbaths where mosquitoes can lay their eggs; and installing screens in windows and doors.

Recently, West Nile virus has been detected as close to Wisconsin as Detroit, Michigan, and Indianapolis, Indiana.

Mosquitoes transmit the virus to people, though not everyone bitten by an infected mosquito will become ill. Most people suffer no symptoms or experience only mild ones. The onset of symptoms usually occurs within five to 15 days after being bitten by a mosquito carrying the virus.

Symptoms can range from mild illness to ailments characterized by fever, headache, muscle aches, swollen lymph nodes and sometimes a rash. More severe illnesses are rare but may include confusion or disorientation, indicating brain swelling, severe muscle weakness or paralysis.

The first case of West Nile virus in the Western Hemisphere was reported in the New York area in 1999. From 1999 to 2000, 82 cases of the disease and nine deaths occurred in New York and New Jersey.

This month, a 71-year-old Georgia woman died of the disease.