BATON ROUGE, La. — Preliminary federal data shows Louisiana has the nation’s fourth-highest rate of dangerous West Nile virus infections, so people should protect themselves from mosquitoes, the state Department of Health says.
The Centers for Disease Control and Prevention says only South Dakota, Colorado and North Dakota have higher rates of West Nile virus infections affecting the brain or nervous system.
“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 Dr. Joseph Kanter, the state health officer. “That said, neuroinvasive disease from West Nile virus can be a devastating condition for some, with the potential for debilitating, life-long ramifications.”
So far this year, 33 people in Louisiana are known to have neuroinvasive West Nile infections, and five of them have died, the Louisiana Department of Health said in a news release Wednesday. That compares to 10 cases or fewer at this time in each of the past three years, and to 29 cases in 2017 and 48 in 2018.
Precautions include using EPA-registered mosquito repellent, making sure windows and doors fit tightly and that all screens are free of holes. The state health department has a detailed list of precautions on its website.
The department said 914 mosquito pools positive for the disease had been found as of Saturday — more than double the number reported at this time in 2021. That indicates very high risk for the virus, it said.
It’s currently the peak of the West Nile season, Kanter said.
“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 mosquitos.”
A large proportion of the reported human cases and positive mosquito pools have been located north of Lake Pontchartrain, the department said.
Most infections don't cause any symptoms, with about 20% developing into flu-like West Nile fever. About 1% develop into neuroinvasive disease, also called West Nile encephalitis, which can cause brain damage and death. Symptoms can include high fever, stiff neck, disorientation, muscle weakness, numbness, coma and paralysis.