West Nile virus (WNV) is a virus that can cause swelling of the brain (encephalitis) or swelling of the lining of the brain and spinal cord (meningitis). WNV is spread to humans primarily by the bite of an infected mosquito. Mosquitoes become infected with WNV when they feed on sick birds that carry the virus in their blood. Crows are very susceptible to infection. Therefore, the presence of dead crows is the best way to predict if WNV is in an area.

Bird Testing

The Muskegon County Health Department no longer submits birds to the State for testing. However, the reporting of dead bird sightings remains an important WNV surveillance tool, as increasing reports of dead birds, particularly corvids (crows, ravens, and blue jays), can indicate increasing human risk for WNV infection in a community.

Reporting a Dead Bird

Reports can be filed online or by calling Vector Control at 724-6007.

Disposing of a Dead Bird

A dead bird should be buried or disposed of in your garbage. Always avoid barehanded contact when handling dead animals. If gloves are not available, you may turn a plastic shopping bag inside out and scoop up the bird with the bag.

Reducing your Risk of Infection

Protect yourself from mosquito bites:

• Apply insect repellent to exposed skin. Be sure to read and follow the manufacturer's directions for use.
• Spray clothing with repellents containing permethrin or another EPA-registered repellent since mosquitoes may bite through thin clothing.
• When weather permits, wear long-sleeved shirts and long pants whenever you are outdoors.
• Place mosquito netting over infant carriers when you are outdoors with infants.
• Consider staying indoors at dawn, dusk, and in the early evening, which are peak mosquito biting times.
• Install or repair window and door screens so that mosquitoes cannot get indoors.

Help reduce the number of mosquitoes in areas outdoors by draining sources of standing water where mosquitoes can lay their eggs and breed.

• At least once or twice a week, empty water from flowerpots, pet food and water dishes, birdbaths, swimming pool covers, buckets, barrels, and cans.
• Check for clogged rain gutters and clean them out.
• Remove discarded tires, and other items that could collect water.
• Be sure to check for containers or trash in places that may be hard to see, such as under bushes or under your home.

What Are the Symptoms of WNV?

• No Symptoms in Most People: Approximately 80% of people (about 4 out of 5) who are infected with WNV will not show any symptoms at all.
• Milder Symptoms in Some People: Up to 20% of the people who become infected have symptoms such as fever, headache, and body aches, nausea, vomiting, and sometimes swollen lymph glands or a skin rash on the chest, stomach and back. Symptoms can last for as short as a few days, though even healthy people have become sick for several weeks.

• Serious Symptoms in a Few People: About 1 in 150 people infected with WNV will develop severe illness. The severe symptoms can include high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness and paralysis. These symptoms may last several weeks, and neurological effects may be permanent.

Other Useful Information

WNV in Michigan

Tables & Maps of WNV Activity in Michigan

Map of WNV Activity in the U.S.