Sharp decline in human West Nile cases, but still work to be done

Sharp decline in human West Nile cases, but still work to be done

SLIDELL, La. (WVUE) - The effort to fight mosquitoes in the state is not only a summer effort, according to Kevin Caillouet with the St. Tammany Parish Mosquito Abatement.

“Every day of the year, we’re out there looking for mosquitoes and trying to minimize their biting,” Caillouet said.

He said they reported the first West Nile-carrying mosquito to the state in May.

“It’s always disheartening to get news of a human West Nile virus, particularly of West Nile neuro-invasive, because it’s such a serious form of the disease,” Caillouet said.

So far in 2019, the Louisiana Department of Health reported nine total cases of West Nile. Five of those cases were instances of neuro-invasive West Nile disease, including one case in St. Tammany Parish.

It’s the most serious of West Nile illnesses. It infects the brain and spinal cord and can cause death, paralysis and brain damage, but infectious disease researchers like LSU Health’s Dr. Frank Lopez say it’s rare.

“Usually people over 60 years of age or immune systems don’t work so well, patients with organ transplants, those people are most at risk for developing those types of infection,” Lopez said.

Lopez said most people with West Nile don’t even know they have it and only some cases develop into fever-like symptoms.

“If you’re asymptotic, you’ll never know. And who knows how many people have been infected with this virus, but have never been tested for it. Most people will never know they’ve been infected, we only know for other reasons they’ve been infected,” Lopez said.

According to the Louisiana Department of Health, 53 cases of West Nile virus were reported in 2018.

Caillouet said compared to the nine cases this year, that’s a steep decline. Still, he said the state’s not in the clear.

“As for what to attribute that to, we don’t know. And reading one year to the next is difficult to answer the question, but like I said it’s a complex disease system. A lot of it has to do with the bird population," Caillouet said.

Caillouet explained that West Nile mosquitoes carry the disease after biting birds, and then bite and infect human hosts. He said the decline may indicate a population of birds that have developed West Nile antibodies. But, he said anyone who walks outside should still protect themselves against bites.

The department of health said two asymptomatic cases have been reported, both of which were only found because the person tried to donate blood.

Lopez said West Nile fever starts to present as flu-like symptoms and if you start to experience that, contact your primary care doctor.

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