Mosquitoes test positive for West Nile

Virus surfaces in Woodlands after weeks of heavy rainfall in area

A sampling of mosquitoes collected from The Woodlands has tested positive for the West Nile virus after the wettest month Texas has ever seen primed environmental conditions for mosquito breeding.

The Texas Department of State Health Services confirmed the West Nile-positive sampling from the South Montgomery County area last week — about a month after county officials performed a preemptive mosquito spraying treatment.

The spraying was prompted by Harris County’s first 2015 human case of the West Nile virus, detected in May and one of seven reported human cases nationwide this year. Montgomery County hasn’t had any human cases this year.

In 2014, there were 32 cases of West Nile in humans in Montgomery County — including one fatality — and 113 in Harris County, by far the most cases of any county in Texas, according to the U.S. Centers for Disease Control and Prevention. The high number in Montgomery County — the highest since 2012, when there were 17 cases — prompted the county to use an aerial spraying method to treat the area last August. The majority of the West Nile cases were reported in the late summer and fall.

The record-breaking rainfall in the county and

throughout the state has resulted in higher-thanusual mosquito populations, said Rick Duhrkopf, regional director for the American Mosquito Control Association and a biology professor at Baylor University. The continuous rains, however, tend to keep water from stagnating, reducing the risk for West Nile-carrying mosquitoes, which breed in still water. The greater threat for the virus will come later in the summer. Still, he said that mosquitoes testing positive for the virus is a warning sign for people to take precautions.

“It dramatically increases the probability (of human infection),” he said. “Positive pools are the first sight of human disease.”

Having a West Nile-positive sample at this time in the year is not unusual for the South Montgomery County area, however, said Justin Fausek, environmental foreman for Montgomery County Precinct 3.

The county generally traps and tests mosquitoes for diseases from May to October and treats areas that test positive for the virus. This year, in light of the human case in Harris County and the high levels of rain, the county treated areas that have tested positive in the past once and then reverted to the standard trapping protocol, Fausek said.

In response to the positive sample found in The Woodlands last week, Montgomery County will follow standard protocol, which includes spraying the affected area with a truck-based spray unit, treating storm drains, catch basins and standing water in the area.

The West Nile virus, which killed four people in Texas and 85 in the United States in 2014, does not cause symptoms in about 80 percent of those infected, CDC data shows. About 20 percent of those infected experience flu-like symptoms, including fever, headache, body aches, joint pains, vomiting, diarrhea or rash, and most recover completely. Less than one percent of those infected develop a serious neurologic illness, and even fewer die.

To prevent contraction of the disease, the CDC recommends avoiding mosquito bites by wearing long sleeves and pants and using repellent containing DEET. Also, eliminate or treat instances of standing water around the yard.

The Woodlands Township warns against overwatering lawns and Fausek emphasized the importance of residents treating their property.

“Most complaints we get are in people’s own yards,” he said.