First Minnesota West Nile case of 2009 reported
The Minnesota Department of Health is confirming the first human case of West Nile virus disease for 2009 in a Minnesota resident, according to a press release.
State health officials are reminding Minnesotans to protect themselves from mosquitoes from now through September.
The Stevens County woman became ill with West Nile meningitis in late June, was hospitalized and is recovering.
The department is encouraging Minnesotans to use mosquito repellents to protect themselves from mosquito bites, the press release said.
Mid-July through September is the period of highest risk for West Nile virus in humans, according to David Neitzel, an MDH epidemiologist specializing in diseases carried by mosquitoes and ticks. The risk is greatest in the state's western and central counties, and the elderly or people who have weakened immune systems face the highest risk of severe illness from a West Nile virus infection, he said.
Several safe and effective options recommended by the health department are:
- Repellents containing DEET (up to 30 percent concentration) are still the most widely used and can provide long-lasting protection against mosquito bites.
- Permethrin is a strong repellent and will kill mosquitoes that come into contact with treated clothing. Repellents containing permethrin are recommended for use on clothing (not skin).
- Effective alternatives to DEET or permethrin include repellents containing picaridin, oil of lemon eucalyptus, or IR3535.
The Minnesota Department of Health also recommends:
- Minimize outdoor activities at dusk and dawn, as this is prime feeding time for West Nile virus -carrying mosquitoes. If you go outside at these times, take precautions even if mosquito numbers seem low; it only takes one bite from an infected mosquito to transmit the virus.
- Wear loose-fitting, long-sleeve shirts and long pants if you must spend time in an area where mosquitoes are biting.
- Culex tarsalis mosquitoes prefer the open, agricultural areas of the state. While the majority of Minnesota's West Nile disease has occurred in people from these areas, cases are possible anywhere within the state. Since West Nile virus was first found in 2002 in Minnesota, 451 cases (including 14 deaths) of West Nile disease have been reported to MDH. In 2008, there were 10 cases reported in Minnesota, with no deaths.
According to the press release: Of those who become infected with West Nile virus, most people will fight off the virus without any symptoms or will develop West Nile fever, the less severe form of the disease. Approximately one out of 150 people bitten by infected mosquitoes will develop severe central nervous system disease (encephalitis or meningitis).
Approximately 10 percent of people with this severe form of West Nile virus infection die from their illness, and many more suffer from long-term nervous system problems. Symptoms usually show up three to 15 days after being bitten. They can include headache, high fever, rash, muscle weakness, stiff neck, disorientation, convulsions, paralysis and coma.
People who have questions about West Nile virus can call the Minnesota Department of Health at (651) 201-5414 or (877) 676-5414 (outstate) between 8 a.m. and 4:30 p.m. Monday through Friday.