In Minnesota we sometimes joke that the mosquito is the state bird. While the number of mosquitoes actually capable of causing infection in humans is fairly small, it is important to take preventive steps to protect you and your family from potentially serious diseases. While the Zika virus is getting a lot of attention today, it is not a threat in the northern part of the U.S. The two most serious mosquito-born diseases found in Minnesota are West Nile virus and La Crosse Encephalitis
West Nile Virus
West Nile virus (WNV) is found in all lower 48 states and was first discovered in Minnesota in 2002. It remains a public health threat because the virus can cause encephalitis (inflammation of the brain) in some people. Thankfully, most bites by infected mosquitoes result in no symptoms or only mild illness.
The typical incubation period for West Nile is 2-6 days, although it can be as long as 15 days. West Nile fever symptoms include:
- Sudden onset of high fever (usually greater than 102°F)
- Severe headache
- Sore throat
- Joint pain
- Prominent muscle aches and weakness
- Prolonged fatigue
- Rash (more commonly associated with West Nile fever than encephalitis)
- Swollen lymph nodes
La Crosse Encephalitis
Like West Nile, La Crosse Encephalitis (LAC) is a virus. Most people infected with this virus will have either no symptoms or a mild flu-like illness. A small percentage of people (especially children) may develop encephalitis (inflammation of the brain).
Most of the severe cases start with headache, fever, nausea, and lethargy. The illness may rapidly progress into disorientation, seizures, and coma. There is no treatment for the illness other than supportive care until the illness is over.
The Minnesota Department of Health Offers These Prevention Tips
- Because mosquitos can breed in only a small amount of water, check your yard to ensure there are no containers like old buckets, tires, kid's pools or other containers that can collect water. Remove the containers or turn them upside down.
- The riskiest time of year for mosquitos in Minnesota is mid-summer through early fall as disease-carrying mosquitoes are more common at this time of year and the viruses that cause disease have had time to become widespread in these mosquitoes.
- Wear mosquito repellent containing DEET (up to 30%).
- Concentrations up to 30 percent DEET are also safe for children (according to reports from the American Academy of Pediatrics). Do not use insect repellent on infants under two months of age.
- Apply repellents containing permethrin to your clothing or gear. Do not use permethrin on your skin.
- Other alternatives are available, including picaridin, IR3535, and oil of lemon eucalyptus.
- Only use products that are registered by the Environmental Protection Agency (EPA).
- Wear loose fitting, light colored, long sleeved shirts and pants. Head nets can also be used in areas with high mosquito populations.
For more information on mosquito-transmitted diseases, visit the Minnesota Department of Health website.