As fall begins and temperatures drop, students pull out their long sleeves and pants to keep them warm. What they may not realize is their clothing choices could also protect them from West Nile Virus, discovered on campus late last month for the second time this year.

As of Aug. 30, the Champaign-Urbana Public Health District announced that two positive results for West Nile had been found in two mosquito pools at the University’s South Farms. These were the first two positive results in 2007. There have been no other reported cases of the virus in Champaign County as of Tuesday.

The Illinois Natural History Survey conducts testing on mosquitoes for the county, using its own traps and the district’s.

One of the positive samples was taken in early May and the other in mid August, said Jim Roberts, director of environmental health at the public health department.

The positive sample from May was released late due to protocol that had to be followed when the previous director of the medical entomology program at the survey retired, said Dr. Richard Lampman, research scientist and interim director of the program.

“We have a very low concentration of positive results,” Lampman said.

This year’s positive results are comparatively low. In 2006, 100 mosquito pools turned up positive. Environmental changes have created a lower mosquito population.

“We had an early warm up and a long cold period, and we got some heavy rainfalls late in the season,” Lampman said. “This washes them out with the storm water system.”

As a preventative measure to keep mosquito population down, the survey treats breeding sites where eggs have been laid, eliminating that population before the new larvae have a chance to hatch and spread.

People can help lower their risk of being bitten and contracting the virus by being aware of what rules to follow.

“Minimize the times you’re outside in dusk and dawn,” Roberts said. “That’s when mosquitoes are most active.”

Roberts also recommends draining water from potential mosquito breeding sites, dressing properly when outdoors and applying mosquito repellents containing DEET to protect against mosquito bites and infection.

Though Sam Garcia, senior in LAS, does not avoid being outdoors during the prime mosquito times, he remembers to use repellent.

“Late afternoon is when they usually come out, but that’s when I’m usually out,” Garcia said, “I do use spray because I hate mosquito bites.”

As winter approaches, the mosquitoes will pose less of a threat because their focus is shifted to looking for shelter.

Days are getting shorter and the temperature is dropping, and these factors will reduce the mosquito population, said Lampman. “The mosquitoes no longer look for people to bite and look for sugar,” he said, “We’re at a low risk level.”