About LaCrosse Encephalitis
On this page:
Fact Sheet
Transmission
Prevention
Signs and symptoms
Fact Sheet
- LaCrosse Encephalitis
Fact Sheet
Answers to frequently asked questions about LaCrosse encephalitis.
Transmission
- LaCrosse encephalitis is one of several mosquito-transmitted
diseases that have been seen in Minnesota.
Prevention
- The best way to prevent LaCrosse encephalitis is to remove water-holding
containers from your property. It is easier to do this in the spring
before growing vegetation obscures the containers.
- Bird baths should have their water changed every week to prevent mosquito
breeding, and gutters should be checked to make sure they are not plugged.
- Water-holding tree holes should be filled with dirt, sand, or a pliable
insulation cement to prevent further mosquito breeding.
- If children play in or near wooded areas during the day, they should:
- wear long-sleeved shirts and long pants (light-colored clothing works best)
- use repellents containing DEET (less than 30% DEET is sufficient
for adults, and less than 10% DEET is adequate for children) according
to label directions
- Preventing
Mosquito-Transmitted Diseases
Learn how to minimize your risk to LaCrosse encephalitis and other diseases transmitted by mosquitoes.
Signs and symptoms
- 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.


