West Nile Cases Reported East of Baton Rouge

The mosquito-transmitted West Nile virus (WNV) has been actively spreading throughout 14 Louisiana parishes since 2002 and continues to do so in 2025.

On June 25, 2025, the Louisiana Department of Health (LDH) confirmed Louisiana’s first human case of WNV of the 2025 mosquito season. This case was confirmed in an individual from Livingston Parish, located east of Baton Rouge and north of New Orleans, who was hospitalized due to complications from the infection.

In 2024, there were 57 confirmed human cases of WNV in Louisiana, including three deaths. 

In 2024, 1,466 WNV cases were confirmed in 49 states in the USA, led by Texas with 176 cases.

The LDH says WNV can cause mild to severe illnesses. While most people infected with West Nile virus develop no symptoms, about 20% of infected individuals develop West Nile fever, a flu-like illness characterized by symptoms that can include fever, headaches, body aches, nausea, and rashes. About 1 in 150 people who are infected with WNV develop a severe illness that can affect the brain, spinal cord, and nerves, which may even cause paralysis or death.

WNV is an international concern.

For example, according to a research program by the UK Health Security Agency and the Animal and Plant Health Agency, WNV genetic material was detected in mosquitoes in Britain for the first time in 2025.

As of June 27, 2025, vaccine candidates to protect people against WNV have not been approved in the United States.