A Bad West Nile Season Coming to North Texas?

The Dallas County Department of Health and Human Services has detected the year's first West Nile virus-infected mosquitoes in the county and warns that could be a bad sign.

"This is the earliest seasonal appearance of West Nile virus (WNV) detected in mosquito populations in Dallas since environmental surveillance began in 2002," the department said in a health advisory issued April 13. "The abundance of this species of mosquitoes is currently higher than expected this early in the season. One adjacent county has also recently identified their first WNV positive mosquito trap for the season, indicating an early wide distribution of WNV in our local mosquito population."

While no confirmed human cases of WNV disease have been reported in Texas this year, the department points out that such cases typically trail the first report of mosquito infection by several weeks. Dallas County has begun ground spraying for mosquitoes in the areas around where the infected insects were found.

Most cases of WNV disease are mild or asymptomatic, according to the U.S. Centers for Disease Control and Prevention (CDC). Less than 1 percent of those infected will develop serious neuroinvasive disease. 

Physicians in the area should consider WNV in patients whose symptoms are consistent with WNV fever (fever with headache, myalgia, arthralgia, weakness, or rash) or West Nile neuroinvasive disease (fever with aseptic meningitis, encephalitis, or acute flaccid paralysis), the department says.

In 2016, counties across Texas reported cases of WNV disease in humans, especially in the northeast and southeast quadrants of the state.

For more information on diagnosis, testing, reporting, and treating WNV disease, see the CDC website.

Action, April 17, 2017

Last Updated On

April 17, 2017

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