PHOENIX – A man in his late 70s is Arizona's first confirmed case of West Nile virus this year.
Health officials said the Phoenix-area man is in a skilled nursing facility recovering from West Nile encephalitis, a serious form of the disease.
In 2010, Maricopa County recorded its second-worst West Nile virus season with 115 lab-confirmed cases.
"We detected a lot of West Nile disease last year and know that what we found is just the tip of the iceberg," said Dr. Bob England, director of the Maricopa County Department of Public Health.
WNV is transmitted to humans by the bite of an infected mosquito. Approximately 20 percent of people infected with the virus will feel flu-like symptoms occurring three to 15 days after the mosquito bite.
Symptoms may include fever, headache, body aches, nausea, vomiting, swollen lymph glands, and skin rash on the chest, stomach and back. A small percentage of people who are infected with WNV will experience severe symptoms, such as meningitis, encephalitis or paralysis, and may result in death.
"Last year about 60 percent of our reported cases were considered to be neuroinvasive illnesses, which is when the disease affects the nerves, brain and spinal cord," England said. "This form is very serious that requires hospitalization and can be deadly."
England said a less severe form of the disease, known as West Nile fever, is highly underreported because many people feel like they have a bad cold or the flu and don't see a doctor so they don't get tested.
"The bottom line is that we are all at risk and need to protect ourselves from those pesky critters," England said.
Public health officials recommend applying insect repellent following label instructions (CDC recommends repellant containing DEET, Picaridin, Oil of Lemon Eucalyptus or PMD, or IR3535), wearing long clothing, and avoiding outdoor activity after dusk and before dawn.
Also, residents should make a special effort to mosquito-proof their home by taking the following precautions:
• Eliminate mosquito-breeding sites around your property. Drain standing water in potted plants, tires and other containers.
• Install or repair window and door screens to keep mosquitoes out of the home.
• Keep fountains, animal troughs and swimming pools properly operating and free from debris.
For more information on West Nile virus, public health assistance, as well as for WNV dead bird drop-off locations, to report green pools or file any mosquito-related complaint, call 602-506-0700 or visit www.maricopa.gov.