La Crosse Encephalitis Virus

La Crosse encephalitis is a mosquito-borne illness that affects about 100 people in the United States every year. When an infected mosquito bites a person, he or she may develop encephalitis, an inflammation of the brain. Although this is a rare disease, taking steps to protect yourself from mosquito bites is the best way to ensure you don't become infected.

The Aedes mosquito, also called the tree hole mosquito, most commonly carries La Crosse encephalitis (or LACV). For people bitten by an infected mosquito, it may take 5 to 15 days before symptoms begin showing up. Symptoms for La Crosse encephalitis include fever, fatigue, headache and vomiting with nausea initially.

Should the disease progress, LACV may cause an inflammation of the brain, which can result in seizures. Should the disease continue to worsen, the infected person could fall into a coma or suffer paralysis. Those who end up with a serious case of La Crosse encephalitis typically are children age 16 and younger.

No treatment exists for La Cross encephalitis, although supportive therapy and hospitalization can help people deal with the symptoms. No vaccine or preventative drug exists for LACV either. Because of a lack of treatment options for LACV, it's recommended people take steps to protect themselves from mosquito bites. With infected mosquitos found in the United States, including in the upper Midwest, the mid-Atlantic and the Southeast, controlling the mosquito population helps to reduce your chances of infection with LACV.

Additionally, mosquitos carrying La Crosse encephalitis can bite at any time outside of winter in the United States. The La Crosse encephalitis virus can survive in mosquito eggs laid late in the fall, that survive the winter and that will hatch during warmer temperatures in the spring. So you may need to begin using products to control the mosquito population early in the spring. The LACV virus MosquitoNix® products, including those made for residential and commercial customers, are available for helping with flying insect control.