The West Nile virus has hit Maricopa County, health officials announced Wednesday.
A dead sparrow a Chandler man turned in Sept. 11 after finding it in an area between Queen Creek and Ray roads tested positive for the virus, said Doug Hauth, spokesman for the county’s Department of Public Health.
"The man looked at the bird and determined that it didn't look like it had died from being hit or killed by another animal and he called environmental services," Hauth said. "He described what he saw and they told him to bring it in."
There has been one reported human case in Arizona in Graham County, but it is believed the man contracted the disease while visiting Colorado or Wyoming, states with considerable West Nile activity.
West Nile virus has now shown up in 10 of Arizona's 15 counties, according to John Townsend, Maricopa County Vector Control Manager.
A confirmed animal case of the virus had been reported as close as Casa Grande in Pinal County earlier this month in a 21-year-old horse that later died of encephalitis caused by the virus.
Hauth said the possibility of people contracting the disease is very low and most people who do contract it never see symptoms.
"Less than 1 percent of people bitten will ever come down with West Nile virus," Hauth said. "Less than that will ever see any symptoms. Those that are more susceptible are the elderly and those with a compromised immune system."
A few people may become ill as a result of the virus with symptoms that resemble the flu and may last a few days, according to state epidemiologist Bob England. West Nile can lead to more serious conditions in rare cases such as encephalitis, an inflammation of the brain, or meningitis, which affects the lining of the brain and the spinal cord, which could lead to death.
There are no human vaccines and no treatment for the disease.
Mosquitoes carry the West Nile virus. They usually pick it up from biting an infected bird. After a few days, an infected mosquito can pass the disease on to humans. The virus is not passed between people or animals and humans, Hauth said.
Maricopa County has a surveillance program for the virus. It includes routinely testing sentinel chickens, mosquitoes, and dead birds for Western equine encephalitis, West Nile virus and St. Louis encephalitis.
To report a dead bird or register a mosquito complaint, call (602) 505-6616. For general health questions about West Nile virus call (602) 506-6767 or visit www.maricopa.gov/envsvc.