Articles & Publications

View Article

West Nile Virus Precautions to Take During Labor Day Weekend

With more Michiganders spending time outside for the extended Labor Day weekend, the Michigan departments of Community Health (MDCH) and Agriculture and Rural Development, and Natural Resources along with Michigan State University (MSU), would like to remind residents of the simple precautions that can be taken to avoid mosquito bites during the holiday.


“As we continue to watch the count of West Nile Virus (WNV) cases climb, Labor Day weekend is an important time to remind Michiganders of the simple precautions they can take,” said Dr. Dean Sienko, Interim Chief Medical Executive at MDCH. “With so many people enjoying the outdoors this coming weekend, we want to be sure that everyone, especially children, the elderly and those with weakened immune systems, are protecting themselves from mosquito bites.”


WNV cases have been on the rise both nationally and in Michigan. As of Wednesday, Aug. 29, there are 80 confirmed WNV cases, including 4 in Ingham County. WNV is also responsible for 4 deaths this year in Michigan. In addition to the human cases, WNV has also been found in livestock and wildlife across the state.


“Signs of WNV in a horse may include stumbling, limb weakness, facial paralysis, difficulty urinating and defecating, fever, blindness, seizures, and struggling to get up,” said State Veterinarian Dr. Steven Halstead. “There is no specific treatment for WNV encephalitis, but supportive care can help horses survive until their natural defenses eliminate the virus.”


Most people bitten by a WNV-infected mosquito show no symptoms of illness. However, some become sick three to 15 days after exposure. Children and people 50 and older are more susceptible to severe WNV disease symptoms.


Michigan residents are encouraged to take the following steps to avoid WNV:

• Apply insect repellents that contain the active ingredient DEET, picaridin, oil of lemon eucalyptus or other EPA approved repellent to exposed skin or clothing.

• Avoid being outdoors at dusk and dawn when mosquitoes are most active.

• Maintain window and door screening to help keep mosquitoes out of buildings.

• Empty water from mosquito breeding sites such as buckets, unused kiddie pools, old tires or similar sites where mosquitoes lay eggs.

• Wear light colored, long-sleeved shirts and long pants when outdoors.


The mosquitoes that transmit WNV to humans lay eggs in small pools of standing water.  Adult mosquitoes can hatch in 10 days in warm weather.  Mosquitoes become infected and transmit WNV after feeding on birds carrying the virus. Within 10 to 14 days, the mosquito can transmit the virus to humans and horses.


Many of the same precautions people take can also be used to protect livestock:

• Since West Nile Virus is spread to horses through the bite of an infected mosquito, protection measures that reduce the exposure to mosquito bites should be adopted.  

• It is not too late to vaccinate horses this season.  Talk to your veterinarian for details.

• Use approved insect repellants to protect horses. If possible, put horses in stables, stalls, or barns, preferably under fans, during the prime mosquito exposure hours of dusk and dawn.

• Eliminate standing water, and drain troughs and buckets at least once a week.


For more information about WNV in Michigan, visit or