A Tarrant County official said Friday that there is evidence that the area has turned the corner on this year's West Nile virus outbreak, as officials in Denton County finalized plans for aerial spraying and confirmed another death from the disease.
Only two mosquito pools tested positive for the West Nile virus out of 26 that were harvested in Tarrant County on Thursday, said David Jefferson, Tarrant County's environmental health manager.
"We're hopeful that we've passed the peak," Jefferson said. "That's what our early analysis shows. The number of human cases and the number of positive mosquito tests typically all trend downward by the end of August."
In Denton County, public health officials reported Friday that a second person had died from West Nile. The woman was a Carrollton resident in her 80s with underlying health conditions, according to a statement. On Tuesday, Denton County Judge Mary Horn declared a health emergency and requested additional resources so the area could begin aerial spraying, a news release said.
A Fort Worth contractor was to begin a weekend of ground spraying in portions of the 76137 ZIP code in north Fort Worth on Friday and finish on Sunday, weather permitting. Ground spraying was also scheduled to continue in Tarrant County in Bedford, Euless, Haltom City, Hurst, Mansfield, North Richland Hills and Roanoke.
Flower Mound officials held an emergency meeting on Wednesday and approved the city's participation in an aerial spraying program. Other Denton County municipalities have until noon Tuesday to make a decision, said Bob Martinez, Denton County public health preparedness coordinator.
Denton County is using the best data available but there is always a small amount of lag time, Martinez said. The number of human cases could go higher in coming days, Martinez said.
"We have not seen a big decline in human cases," Martinez said. "We may not know about some people who are currently sick with neuro-invasive disease because they have not gone to the hospital yet."
As of Friday, Denton County has recorded 119 human West Nile virus cases this year and two deaths while Tarrant County has reported 231 human cases and four deaths. Dallas County has reported 291 human cases and 11 deaths.
Jefferson said he does not know when the outbreak might end, and that Tarrant County public health officials will continue to monitor mosquito traps until the end of October.
Human cases of West Nile will likely continue to pop up through September, "but they will be fewer and farther between," Jefferson said.
In Denton County, public health officials had only one positive mosquito pool this week out of 20 pools tested, said Jim Kennedy, a biology professor at the University of North Texas.
"I think the downward trend has been established," Kennedy said. "We may see resurgence of the mosquito population but not of West Nile."
Mitch Mitchell, 817-390-7752