
West Nile Virus
West Nile virus has been actively spreading throughout Louisiana since its first detection in the state in 2002.
West Nile virus is spread to people by mosquitoes and can cause mild to severe illnesses. While most people infected with West Nile virus develop no symptoms, about 20% of infected people develop West Nile fever. West Nile fever is a flu-like illness with symptoms that can include fever, headaches, body aches, nausea, and rashes.
A small percentage of infected people develop West Nile neuroinvasive disease, a severe illness that affects the central nervous system and can result in hospitalization or even death. Symptoms can include high fever, stiff neck, disorientation, muscle weakness, numbness, coma, and paralysis. These symptoms may last several weeks and carry the risk of death or permanent damage.
It is important to protect yourself from mosquito bites to prevent illness. People 55 years of age and older and people with certain medical conditions are at a greater risk for severe disease if they are infected.
Protect yourself against mosquitoes
- Wear EPA-registered mosquito repellent outdoors and always follow label instructions.
- Apply repellent on exposed skin only. Do not apply under clothing or on broken skin.
- Carry a travel-size repellent if you will be outdoors for an extended period.
- Apply sunscreen first, insect repellent second, if you are also wearing sunscreen.
- Make sure windows are tight-fitting and screens are free of holes to keep mosquitoes out.
Protect your home from mosquitoes
- Eliminate standing water around your home, which is where mosquitoes breed.
- Turn over wheelbarrows, plastic wading pools, buckets, trash cans, children’s toys, and anything that can collect standing water.
- Quickly discard or store any containers around your home to avoid accumulating water. Drill holes in standing containers to drain water quickly.
- Clean roof gutters routinely. Clogged gutters can produce millions of mosquitoes annually.
- Take steps to prevent water gardens and ornamental pools from stagnating (and becoming major mosquito producers), such as adding fish or aeration.
- Clean bird baths weekly, as changing the water keeps it from stagnating and becoming a breeding area for mosquitoes.
- Clean and chlorinate swimming pools, especially if they go unused. Be aware that mosquitoes also breed in water accumulated on pool covers.
- Install or repair window screens.
WNV Surveillance Reports
Surveillance for West Nile Virus (WNV) was initiated in Louisiana in the Spring 2000 and currently involves the testing of sick horses and mosquito pools. With the exception of horse testing, WNV testing is performed at the request of individual mosquito abatement districts throughout the state.
- Louisiana has four kinds of Encephalitis - West Nile, Saint Louis, Eastern Equine, and California. To learn more, view the Annual Encephalitis Reports.
- For more on West Nile Virus, view Frequently Asked Questions (FAQ).
Find current year and previous year reports of WNV activity in our LDH Resources.
Dead Birds
WNV is considered endemic, or native, to all parts of Louisiana. Dead bird testing is a poor predictor of human cases statewide, thus statewide dead bird reporting has been discontinued. Its value is limited unless part of a more comprehensive mosquito surveillance program, such as conducted by local or parish mosquito abatement districts.
Our Partners:
- American Mosquito Control Association
- Louisiana Department of Agriculture and Forestry
- Louisiana Department of Wildlife and Fisheries
- Louisiana Mosquito Control Association
- LSU Animal Disease Diagnostic Laboratory (LADDL)
- Tulane University School of Public Health & Tropical Medicine
- Office of Public Health Laboratory
- Office of Public Health Sanitarian Services
For more information, contact Sean Simonson [email protected] via email or at (504) 568-8342.