Louisiana has the fourth-highest rate of West Nile virus neuroinvasive disease (NID) in the country, according to preliminary data from the Centers for Disease Control and Prevention (CDC). The Louisiana Department of Health (LDH) reminds the public to continue taking precautions against mosquito bites that can expose people to the virus. 

To date this year, Louisiana is reporting a total of 33 NID cases in the state and 3 West Nile fever cases.

Five individuals diagnosed with NID in Louisiana have died. 

This is significantly more NID cases than in the previous 3 years — 10 cases at this time in 2021, 5 cases in 2020 and 6 cases in 2019. But it is comparable to the 2017 and 2018 seasons — 29 cases and 48 cases at this time respectively.

LDH continues to receive reports of high numbers of mosquito pools positive for the West Nile virus, with 914 positive mosquito pools reported as of September 17, 2022. For context, only 409 positive mosquito pools were reported at this time in 2021. This indicates the risk of West Nile virus remains very high.

While the risk of West Nile virus infection is high throughout Louisiana, a large proportion of the reported human cases and positive mosquito pools have been located in the Northshore area.

Due to the high number of cases, positive pool samples and the increased risk of the West Nile virus spreading to humans, LDH is urging the public to take protective measures against mosquito bites.

“Most cases of West Nile fever go unreported, because individuals with mild fevers or flu-like illness are less likely to seek medical care or testing,” said State Health Officer Dr. Joseph Kanter. “That said, neuroinvasive disease from West Nile virus can be a devastating condition for some, with the potential for debilitating, life-long ramifications. While we are in the height of season, I urge families across the state to take the simple steps of protecting themselves from mosquito bites and turning over any containers holding standing water around the outside of the house, which can serve as breeding sites for these mosquitoes.”  

The West Nile virus is spread by mosquitoes and can cause illness in people and animals. Most infections with the West Nile virus are asymptomatic, with only about 20% of cases developing into West Nile fever and only 1% developing into NID.

A flu-like illness, West Nile virus symptoms can include fever, headache, body aches, nausea or rashes. A small percentage of people sickened by West Nile virus can develop a severe form of infection called West Nile neuroinvasive disease or West Nile encephalitis, which can result in hospitalization and death. Symptoms can include high fever, stiff neck, disorientation, muscle weakness, numbness, coma and paralysis.

Tips to protect yourself against West Nile

If you will be outside, you should wear EPA-registered approved mosquito repellent and always follow product label instructions. 

  • Apply repellent on exposed skin and clothing, but do not apply under your clothes or on broken skin. 
  • If you are also using sunscreen, apply sunscreen first and insect repellent second. 
  • To protect yourself from being exposed to mosquitos while indoors, make sure that windows and doors are tight-fitting and that all screens are free of holes.

Protecting your home from mosquitoes

  • Reduce the mosquito population by eliminating standing water around your home, which is where mosquitoes breed.
  • Dispose of tin cans, ceramic pots and other unnecessary containers that have accumulated on your property that may collect water. Turn over wheelbarrows, plastic wading pools, buckets, trash cans, children's toys or anything that could collect water.
  • Drill holes in the bottom of outdoor recycling containers. If a recycling container has holes on the sides, there is still room for the container to collect water for mosquitoes to breed, so holes should be added on the bottom if not already present.
  • Check and clean roof gutters routinely. Clogged gutters can produce millions of mosquitoes each season.
  • Water gardens and ornamental pools can become major mosquito producers if they are allowed to stagnate. Take steps to prevent stagnation, such as adding fish or aeration.
  • Clean and chlorinate swimming pools that are not being used. A swimming pool that is left untended by a family for a little as a month can produce enough mosquitoes to result in neighborhood-wide complaints. Be aware that mosquitoes may even breed in the water that collects on swimming pool covers.
  • Contact local mosquito abatement districts to report mosquito problem areas.