Michigan West Nile Virus Update: Total Human Cases 409

October 9, 2002



            The Michigan Department of Community Health today announced eight new cases of West Nile virus disease in humans, for total of 409 probable and confirmed cases in Michigan.  No additional deaths were reported.  The total number of deaths in Michigan associated with West Nile virus disease remains at 28.


             “Transmission can continue as long as mosquitoes are active, and some species can maintain activity into November,” said Department of Community Health Chief Medical Executive, David R. Johnson, M.D.  “People should be aware of and follow the simple, common-sense precautions to reduce exposure to mosquitoes.  We cannot yet let our guard down.”


            Individuals with fever and signs of encephalitis or meningitis should be tested for West Nile virus.  Symptoms of encephalitis (inflammation of the brain) and meningitis (inflammation of the spinal cord and brain linings) include severe headache, stiff neck, stupor, disorientation, coma, tremors, muscle weakness, convulsions and paralysis.  Physicians are also urged to test patients for West Nile virus if they present with sudden, painless paralysis in the absence of stroke.


            Case information can be found at http://www.michigan.gov/mdch and by clicking on “West Nile virus.”  The new cases are as follows:


  • Kent County has one new case for a total of 47 cases.
  • Wayne County has seven new cases for a total of 131 cases.


            Although on-going investigations demonstrate that the virus may rarely be transmitted to recipients of organ transplants or blood transfusions or through breast feeding, it is well documented that West Nile virus is spread to humans by infected mosquitoes and is NOT transmitted from person-to-person, horses to people, or birds to people.  People cannot get it from touching or kissing others who have the virus or from a health care worker who has treated someone with it.  There are many ways to reduce the risk of becoming infected, including:


  • Applying insect repellant that contains the active ingredient DEET to exposed skin or clothing, always following the manufacturer’s directions for use on the label.
  • Maintaining window and door screening to keep mosquitoes out of buildings.
  • Draining standing water in the yard.  Empty water from mosquito breeding sites, such as flower pots, pet bowls, clogged rain gutters, swimming pool covers, discarded tires, buckets, barrels, cans and similar sites in which mosquitoes can lay eggs.
  • Avoiding or minimizing outdoor activity at dawn, dusk and early evening when mosquito activity is high.  If outdoors, wear light colored long-sleeved shirts and long pants.


Blood, organ, tissue and bone marrow donation do not pose any risk of West Nile virus to the donor.  Information on organ donation can be found at http://www.giftoflifemichigan.org and blood donation information can be found at http://www.semredcross.org/.


            For communities considering additional mosquito control efforts, the Michigan Departments of Agriculture and Community Health recommend the following:

  • Involve the community as much as possible in the development and implementation of additional mosquito control efforts. 
  • Visit the Department of Agriculture’s web site at www.michigan.gov/mda for a list of vendors licensed and certified to do mosquito control work.  Contact the Pesticide and Plant Management Division (517-373-1087) or the nearest MDA regional office for further information or for assistance in developing comprehensive and integrated plans.
  • Use the lowest volumes, lowest concentrations of the least toxic mosquito control products that will be effective.
  • For controlling mosquito larvae, focus on standing water that cannot be drained (e.g., catchment basins).
  • For controlling adult mosquitoes, focus on community green spaces (e.g., cemeteries, parks, golf courses) at nightfall and in the absence of human activity.


West Nile virus has been detected in birds in 71 counties and in 145 horses in Michigan.