As confirmed cases of the West Nile virus in the Valley increase, health officials are warning people to take precautions while outdoors.
The West Nile virus, a mosquito-spread illness, was discovered first in September, in a bird in Maricopa County.
Thirteen more mosquitoes and birds in Maricopa County tested positive for the virus Sept. 30.
Gary Septon, chief of medical services at the ASU Student Health and Wellness Center, said no students had come in yet and expressed worry about West Nile.
"It's no big deal at this point," he said, "but who knows about next year?"
Septon also said the testing for the virus in Arizona is available only to hospitalized patients, so even if students were worried, they could not be tested.
"It's extremely unlikely they'll get sick even if they were infected," he said, adding that most cases were resolved within a week without long-term effects.
Once the virus hits an area, it's there to stay, said Jeanene Fowler, spokeswoman for Maricopa County Environmental Services.
"Once it gets into the ecosystem, there isn't any way to get rid of it," she said. "You have to learn to live with it."
Fowler said the number of cases next year is expected to rise and become more common in humans if Arizona follows the pattern of other states.
"The second year is always worse," she said. "We're preparing for the worst and hoping for the best."
Mosquitoes get the virus from feeding on infected birds and then spread it to humans and other animals, the effects of which range from mild sickness to death. It cannot be spread from one person to another.
The best way for people to protect themselves is to get rid of standing water near their houses, since that is where mosquitoes breed, Fowler said. She also recommended using an insect repellent when outdoors.
There are almost no symptoms of the virus, although some people report fevers, headaches and body aches.
One human case of the virus in Arizona was reported in Graham County earlier this year, although health officials suspect it was contracted while the man was visiting another state.
August and September are the most likely months for infection because of climate conditions, Fowler said. Mosquitoes are most prevalent in wet areas with warm temperatures.
Maricopa County Environ-mental Services routinely tests mosquitoes and chicken flocks around the county and encourages people to bring in dead birds for testing.
Reach the reporter at katherine.j.krzys@asu.edu.
