The patient, who contracted the illness in Pima County, is recovering and is not hospitalized. She does not pose a health threat to other residents. West Nile virus is not spread from one person to another.

“While this is the first human case reported who contracted the disease in the state, our surveillance data has indicated the presence of the West Nile virus in 12 of the 15 counties in Arizona. We knew it was just a matter of time before someone acquired the disease in the state. The good news is this person is recovering,” said Craig Levy, manager of the Vector-Borne Diseases Program.

Testing done at the State Health Laboratory identified this patient as a probable case, with official confirmation pending from the Centers for Disease Control and Prevention. To date, the State Lab and the University of Arizona Veterinary Diagnostic Lab have collectively confirmed West Nile virus infection in 88 horses, 69 mosquito pools, 38 dead birds, and 14 sentinel chickens statewide.

Dr. Karen Lewis, an infectious disease specialist with the Department, said that the state’s first locally acquired human case of West Nile should cause residents to take precautions, but not to overreact.

“The chance that any one person is going to become ill from a mosquito bite is low,” she said. “Most people do not become ill, and for those who do, most suffer only a mild flu-like illness for a few days before they recover.”

Dr. Lewis said that people who do become more seriously ill with encephalitis tend to be those 50 years of age and older.

The best way to protect yourself from mosquito-borne illness is to reduce the number of mosquitoes around your home and neighborhood and to take personal precautions to avoid mosquito bites, such as:

• Eliminate standing water where mosquitoes can breed. Check for items outside the home that collect water, such as cans, bottles, jars, buckets, old tires, drums and other containers.
• Change water in flower vases, birdbaths, planters and animal watering pans at least twice a week.
• Repair leaky pipes and outside faucets, and move air conditioner drain hoses frequently.
• Avoid being bitten by mosquitoes when going outside at night by using insect repellent. Wear lightweight clothing that covers the arms and legs.

Local health departments are accepting dead birds for testing of West Nile virus if they meet certain conditions. Not all dead birds are eligible or will be accepted for testing.

For more information about mosquito-borne viruses and dead bird reporting, please visit the Arizona Department of Health Services’ Web site at or call the State Public Health Hotline at (602) 364-4500 or statewide toll-free at (800) 314-9243.