West Nile outbreak—more questions than answers

August 27, 2012 by Keith Brannon
West Nile outbreak--more questions than answers
The numbers of West Nile-infected mosquitoes they’re finding in Louisiana this year “are just crazy — off the charts,” says Dawn Wesson, an associate professor at the Tulane School of Public Health and Tropical Medicine. Photo: Paula Burch-Celentano

The weather may not be the only culprit behind the country's worst outbreak of West Nile virus. Public health researchers are investigating whether the virus itself has changed.

Dawn Wesson, associate professor of tropical medicine at the Tulane University School of Public Health and , is working with local officials and colleagues at Louisiana State University to collect and study mosquitoes in South Louisiana.

Investigators track how many of the insects are infected and isolate the virus in the lab to study its infection dynamics to determine what might be different than prior strains. So far, the numbers of infected mosquitoes they're finding in the state this year "are just crazy—off the charts."

"We have never had this many mosquito infections before," Wesson says. "The virus may have mutated and is acting a bit differently."

Researchers want to find out whether this year's strain of West Nile is more infectious for mosquitoes, the primary vector. So far, there are more questions than answers. Is this strain less virulent for people, but better at latching onto the vector?

Wesson and colleagues hope to shed further light on why this West Nile season has been so active. There have been 1,118 cases and 42 deaths in the United States with 640 severe cases, as of Aug. 22. 

Most agree that weather is the primary factor behind the increase. A late drought last year helped concentrate populations of birds who carry the virus and mosquitoes that transmit it. A mild winter meant more of the insects survived and bred, while a wet summer in the South caused a population boom for .

The good news is that is having an impact in reducing mosquito populations in areas with outbreaks, Wesson says. Her advice is to take precautions when going outside by wearing long sleeves and using a DEET-based repellant.

Explore further: Mosquito sample with West Nile virus found in Oakley, Calif.

Related Stories

Officials: West Nile outbreak 1 of largest in US

August 22, 2012

(AP) — There are four times the usual number of cases in the current West Nile outbreak in the U.S. and it's too early to say how bad it will be at year's end, federal health officials said.

Precautions against West Nile virus recommended

August 24, 2012

"Fight the bite!" was the advice Vice President for Administration Kevin Kirby gave to Rice students, faculty and staff in an email Wednesday about precautions against the West Nile virus.

Recommended for you

Researcher making headway in fighting migraines

December 5, 2016

A study by a UT Dallas researcher has revealed new information about a potential chemical causing pain hypersensitivity in migraines, which is the third most common disease in the world.

Zika in fetal brain tissue responds to a popular antibiotic

November 30, 2016

Working in the lab, UC San Francisco researchers have identified fetal brain tissue cells that are targeted by the Zika virus and determined that azithromycin, a common antibiotic regarded as safe for use during pregnancy, ...

Zika and glaucoma linked for first time in new study

November 30, 2016

A team of researchers in Brazil and at the Yale School of Public Health has published the first report demonstrating that the Zika virus can cause glaucoma in infants who were exposed to the virus during gestation.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.