Officials with the Louisiana Department of Health are reporting that the state has seen its first human cases of West Nile virus in 2019, including four cases in Washington Parish.

LDH officials said that five cases of the neuroinvasive disease have been reported in the state so far — two cases in Washington Parish, and one case each in St. Tammany, East Baton Rouge and Livingston parishes.

Neuroinvasive disease is the most serious type of disease associated with the West Nile virus. It infects the brain and spinal cord, and can lead to death, paralysis and brain damage.

Fewer than 1 percent of people infected with West Nile virus develop neuroinvasive disease.

There have also been reports of two cases of West Nile fever — one in Washington Parish and one in East Baton Rouge Parish.

The West Nile fever is a milder viral infection in which patients experience flu-like symptoms. Some symptoms include fever, headache, body aches, nausea, and — less frequently — skin rashes on the chest, stomach, and back, or sometimes swollen lymph glands or eye pain. Typically, about 20 percent of people infected with West Nile virus develop West Nile fever.

Two asymptomatic cases were also reported — one in Washington Parish and one in Caddo Parish. Both cases were diagnosed because of a blood donation, LDH officials said.

The majority of people who contract West Nile virus are asymptomatic, which means they show no symptoms of viral disease.

At this same time last year, 53 West Nile cases had been reported in the state of Louisiana.

West Nile virus is spread most commonly by the bite of infected mosquitoes, especially the southern house mosquito species. In rare instances, the virus has been spread by blood transfusion, organ transplant, breastfeeding, and from mother to child during pregnancy. West Nile virus is not spread by casual contact — such as touching, kissing, or caring for someone who is infected.

Symptoms generally occur 3 to 14 days following the bite of an infected mosquito.

State health officials have suggested that heavy rains during the summer have helped to keep down the number of reported cases of West Nile virus, due to mosquitoes not having as much stagnant water available.