Michigan's First 2006 West Nile Virus Positive Bird Found
Researchers have positively identified the state’s first bird infected with the West Nile Virus (WNV) this year. The crow – found in Muskegon County – was collected earlier this month and tested positive for WNV today at Michigan State University’s Diagnostic Center for Population and Animal Health.
“Citizens need to be aware of the potential risk of WNV infection in Michigan, and communities should use surveillance information to target intervention and prevention strategies in areas where WNV activity has been detected,” said Janet Olszewski, Director of the Michigan Department of Community Health (MDCH). “Because we cannot predict the impact WNV will have on Michigan again this year, it is crucial that we continue our efforts with virus surveillance, mosquito control activities, and public education.”
Late spring typically signals the beginning of the season for mosquito-borne diseases, such as WNV in Michigan. Surveillance activities for WNV continue this year as a cooperative partnership involving the Michigan Departments of Agriculture, Community Health, Environmental Quality and Natural Resources, Michigan State University, and local health departments throughout the state.
All agencies are integral parts of Michigan’s WNV surveillance, prevention, and response strategies. Mosquitoes most likely to transmit WNV to humans lay eggs in small collections of stagnant water.
In 2005, Michigan experienced a higher than average WNV year, with 62 reported cases and four deaths. Last year, a total of 131 birds statewide tested positive for WNV, and 13 horses across the state also tested positive for the illness.
Michigan can expect to experience WNV infection in birds, mosquitoes, horses, other animals, and humans in 2006, but the magnitude of the impact cannot be predicted.
“Since West Nile virus is spread to humans and horses almost exclusively through the bite of an infected mosquito, people need to take measures that reduce the chance of receiving mosquito bites,” said Dr. Dean Sienko, acting state Chief Medical Executive. “Preventing exposure to mosquitoes in the months ahead will be important.”
Most people bitten by a WNV infected mosquito show no symptoms of illness. However, some become sick three to 15 days after exposure.
Persons aged 55 and older are more susceptible to severe WNV disease symptoms. Physicians are urged to test patients for WNV if they present with fever and signs of meningitis or encephalitis, or sudden painless paralysis in the absence of stroke in the summer months. Blood donor screening for WNV is expected to continue in 2006.
Adult mosquitoes can hatch in as short as 10 days time in the warmest months of the summer. Mosquitoes become infected with WNV after feeding on sick birds carrying the virus. Within 10 to 14 days, the mosquito can transmit the virus to humans.
Michigan residents are encouraged to:
· Maintain window and door screening to help keep mosquitoes out of buildings.
· Drain puddles in the yard, emptying water from mosquito breeding sites such as buckets, troughs, barrels, old tires or similar sites where mosquitoes lay eggs.
· Avoid being outdoors when mosquitoes are most active (dawn and dusk)
· Wear light colored long-sleeved shirts and long pants when outdoors.
· Apply insect repellants that contain the active ingredient DEET to exposed skin or clothing, always following the manufacturer’s directions for use. (Avoid applying repellent to children less than 2 years of age, and to the hands of older children because repellents may be transferred to the eyes or mouth potentially causing irritation or adverse health effects).
Collection of information on the sightings of sick and dead wild birds and mammals is necessary for monitoring the risk of WNV to humans, wildlife and domestic animals. For rapid reporting of a sighting, please use the web-based reporting form by visiting the state's web site www.michigan.gov/emergingdiseases.
For those without Internet access, you may use your local library to access the Internet or call the statewide toll-free number at: 1-888-668-0869 for updated information about WNV.