Standing water left behind by Tropical Storm Isaac could cause more danger than the storm’s gusting winds and relentless rain.

Mosquitoes need very little water — as much as a bottle cap full — to serve as a breeding ground, according to the Mississippi Department of Health, and in less than three weeks’ time, depending on environmental factors, the flying bloodsuckers are ready to spread diseases including West Nile Virus.

For homeowners, that means emptying any standing water on their property because most mosquitoes bite close to their breeding ground, said state epidemiologist Dr. Thomas Dobbs with the state health department.

“Most mosquitoes don’t travel farther than a mile or two from their breeding ground,” he said.

City and county officials were to start spraying for mosquitoes again tonight, after waiting for winds to calm.

Mosquito spraying rigs used by the city have safety features that do not allow the sprayer to work in high wind, said Glen Dent, who has driven one of the trucks for 15 years. Trucks also must maintain a very specific speed for the sprayer to work.

“It won’t work at 15 miles per hour and it won’t work at 20 miles per hour,” Dent said. “We have to drive between 16 and 19. It’s a slow process.”

So far this year, Warren County has had one confirmed human case of West Nile, according to the state health department. After the diagnosis was made public, River Region Medical Center officials said they had not treated anyone for the virus.

No one was treated at River Region for West Nile because, like with most cases of the virus, the patient was well before the test results were available, said Dr. Jonathan Oluwatade.

State health officials estimate that as many as 80 percent of people infected with West Nile never get sick, and only 1 out of every 150 people becomes severely ill. Oluwatade said the number of symptomless cases could be far greater.

“The main problem is that this disease is underdiagnosed,” Oluwatade said.

Early symptoms of West Nile often mimic a cold or the flu, Oluwatade said.

“I don’t think anybody at this time of the year should ignore rash, fever or generalized body aches,” he said.