SAN ANTONIO -- For a second day in a row, crews at Joint Base San Antonio-Fort Sam Houston fogged areas considered hot spots for mosquitoes carrying the West Nile virus.
This comes a week after 13 pool samples tested positive for the virus.
Ft. Sam Houston spokesman Brent Boller said that crews laid down larvicide bacteria to kill larvae prior to the fogging, but after receiving the positive samples, they decided to target the adult mosquitoes.
"The pesticide being used is called a synthetic pyrethroid, which kills the mosquito on contact and dissipates fairly quickly and leaves very little residual so fogging is different than aerial spraying." Boller said.
Crews used handheld sprayers and covered about five acres in five hours.
Pest controller Keith Foster said they are fogging overnight because that's when most of the mosquitoes come out to feed.
"The adult mosquitoes are the ones that bite," he said. "They are the ones that fly through the air. We put out a fog where they are going to be. When they come in contact with it, it kills them."
A 77-year old San Antonio man died last week, bringing the total number of West Nile deaths in the state to 24. He was the only confirmed West Nile-related death in Bexar County.