West Nile Virus Linked To Future Health Problems Even For Healthy Adults

As the Dallas area sprays for mosquitoes for the first time in decades, health officials here in the Houston area say we've seen a sharp increase in mosquito samples that have tested positive for West Nile Virus. One local doctor says the virus could cause big problems long after an infection.

In Dallas, ten people have died and more than 200 have gotten sick as a result of the West Nile Virus. It’s an outbreak that’s never been seen there and health officials have reached out to Harris County for advice on how to deal with it. Dr. Rudy Bueno heads Harris County Mosquito Control, a robust program that’s been in place since the 1970’s.

“A number of individuals have called just wanting to ask what we do. Sometimes they ask what kind of chemicals we may be using. What kind of spray control tactics we have and have used in the passed, and so we inform them of that.”

West Nile became a problem in the U.S. back in 1999 during an outbreak in New York City. It made its way to Houston in 2002. Birds host the virus and it’s spread when mosquitoes feed on them and then bite humans.

Dr. Kristy Murray is a professor at Baylor College of Medicine and has been studying the virus for more than a decade.

“What we see here in Texas is every three years we have on outbreak, starting in 2003 with our highest number of cases that particular year. We had another increase in our cases in 2006 and then 2009. Actually, we were anticipating that this would be a big year again just because we were in that three year pattern.”

In the Houston area, there have been 14 confirmed human cases of the virus and one death this year. Murray says for each confirmed case, 150 people get the virus and don’t know it. But she says those same people could be at risk years later.

“The thing is that right now, we just actually published a paper this past month where we found that these individuals are actually showing signs of kidney disease years later. And so one of our concerns right now is that, yes, they might not have anything during the acute phase of infection, they’re young healthy people, but we could potentially see long term effects
of the infection down the road.”

Currently there are no West Nile Virus vaccines available, although several have made it out of clinical trials. Murray says
she’d like to see drug companies move the process along.

“I think they looked to see whether or not there could be a market for it and they didn’t feel that there was. I’m hoping with a lot of the work we’re doing that it will show that we really should have a vaccine available for individuals, and it would be nice if we could move that vaccine through the pipeline, so that it could be approved for human use.”
In Harris County, 311 mosquito pools have tested positive this year for West Nile Virus. Seventy-five dead birds have also tested positive, up from 59 birds just last week.