August 24, 2012 5:45 AM
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.
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.”
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 mosquitoes.The good news is that aerial spraying 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.
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