West Nile Virus Update

Michigan Department of Community Health Director, James K. Haveman, Jr. and Michigan Department of Agriculture Director, Dan Wyant today reminded individuals, especially senior citizens, of the precautions they can take to protect themselves from West Nile Virus and provided a testing update. Last week, it was announced that West Nile virus had been detected in a crow found in Royal Oak and a crow found in Clinton township. Ongoing public health surveillance for the virus has not detected any cases of West Nile virus in humans in Michigan.

"We know the risk of developing serious illness from West Nile virus is low, and that most people infected with the virus have no symptoms of illness, but it is important for everyone to take precautions to protect themselves from mosquitoes," said Haveman.

"Since the risk of West Nile encephalitis is higher in persons 50 years of age and older, we strongly urge Michigan seniors to use insect repellent that contains the active ingredient DEET and avoid outdoor activities during prime mosquito exposure hours of dusk and dawn."

Testing over the weekend confirmed the presence of West Nile virus in six additional crows found in Southeast Michigan. This brings the total number of crows that have tested positive for the disease in Michigan to eight.

The additional crows were discovered dead and sent by local health departments to the Animal Health Diagnostic Laboratory at Michigan State University for testing. Additional testing done by the Michigan Department of Community Health laboratory confirm the presence of the West Nile virus in these six crows. The infected crows were found in Southfield, Birmingham, northern Detroit in proximity of the state fairgrounds, Oak Park and two in Royal Oak.

In response to these detections, the Department of Agriculture and local health departments have increased mosquito surveillance in these areas. Through increased surveillance it can be determined if mosquitoes in these counties are carrying the virus.

"With the Labor Day weekend approaching, we want everyone to take the all the simple precautions they can to ensure a safe and healthy holiday," said Wyant. "People can still enjoy the outdoor activities, but should take precautions to minimize exposure to mosquitoes."

"We will continue our human surveillance activities in collaboration with physicians and other health care providers, particularly in southeast Michigan to identify any human case of West Nile virus," said Department of Community Health Chief Medical Executive Dr. David Johnson. The Department works closely with physicians, infection control practitioners, hospital epidemiologists, laboratory directors and local health departments to identify any possible cases of human disease in Michigan.

Residents who find a dead crow or blue jay should contact their local health officials or report them to the State's West Nile virus toll-free hotline at 1-888-668-0869. Only black crow and blue jay specimens should be submitted for testing and decomposed or mutilated birds should not be submitted. Information on West Nile virus can be found on the Department of Agriculture website at http://www.mda.state.mi.us and Centers for Disease Control and Prevention website at http://www.cdc.gov.

Mosquitoes become infected with West Nile virus when they feed on infected birds that carry the virus in their blood. After 10 to 14 days, the mosquitos salivary glands become
infected and those infected mosquitoes can then transmit the virus to humans and other animals while biting them to take blood. During blood feeding, the mosquito injects the virus into the animal or human, where it multiplies and may cause illness. Most crows are very susceptible to infection with West Nile virus and will die within 2-3 weeks of infection.

Most people infected with the West Nile virus have no symptoms of illness, but some may become ill three to 15 days after the bite of an infected mosquito. Based on preliminary evidence, about one in four infected persons will have mild illness with fever, headache and body aches, sometimes with skin rash and swollen lymph glands. Encephalitis is less common and may include headache, high fever, stiff neck, stupor, disorientation, coma, tremors, convulsions, muscle weakness and paralysis. In a few cases, mostly among the elderly, death may occur.

The virus is NOT transmitted from person-to-person. You cannot get the virus from touching or kissing a person who has the disease or from a health care worker who has treated someone with the disease.

While there is no human vaccine for West Nile encephalitis, there are many ways to reduce the risk of becoming infected. They include:
-- Apply insect repellent that contains the active ingredient DEET to exposed skin. Follow the manufacturer's directions for use on the label.
-- Spray clothing with repellents containing permethrin or DEET because mosquitoes may bite through thin clothing. Follow the manufacturer's directions for use on the label. Vitamin B and "ultrasonic" devices are NOT effective in preventing mosquito bites.
-- Avoid applying repellent to children under 2 years of age, and to the hands of older children because repellents may irritate the eyes and mouth.
-- Maintain window and door screening to keep mosquitoes out of buildings.
-- Drain 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.
-- Wear long-sleeved shirts and long pants when outdoors.