PHOENIX -- A woman in her 40s is the state's first human case of West Nile virus this season in Maricopa County, health officials said.

The woman has been released from a local Valley hospital and is currently recovering from the virus, the Maricopa County Department of Public Health and Arizona Department of Health Services confirmed.

It is the third case of the disease in the United States this season.

"With the Independence Day holiday upon us, this first case is a reminder of the precautions we should all be taking this weekend," said Dr. Bob England, director of the Maricopa County Department of Public Health.

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.

"This year mosquitoes positive for West Nile virus were discovered before we confirmed our first human case," said John Kolman, interim director for the Maricopa County Department of Environmental Services. "This shows us that our surveillance is working."

The virus is transmitted to humans by the bite of an infected mosquito, officials said. About 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 the virus will experience severe symptoms, such as meningitis, encephalitis, paralysis and even death.

People over the age of 50 are generally at a higher risk for severe symptoms. Health officials say Valley residents should be aware that although the majority of people who become infected with the virus will show no symptoms at all, for a small percentage of people it can be serious or even fatal.