A mosquito sample in Maricopa County has tested positive for West Nile virus, signaling an early start to the season.
The Maricopa County Environmental Services Department reported mosquito traps returning with an increased number of mosquitoes last week.
MCESD conducts year-round surveillance of mosquitoes. Technicians collect samples and run tests on the samples collected from many locations throughout the Valley.
Last year, Maricopa County reported 168 positive mosquito samples and 76 lab-confirmed human cases with two deaths.
In 2004, when the county led the number of cases across all counties in the nation, West Nile infected 355 people in Maricopa County and 14 people died from the disease.
The condition is transmitted to humans by the bite of an infected mosquito. About 20 percent of people infected with West Nile virus will feel flu-like symptoms, such as a fever, headache and rash.
A small number of those infected will experience severe symptoms such as meningitis, paralysis or even death, health officials said.
Older people and those with weakened immune systems are most at risk for severe illness.
Residents are urged to think about taking precautions to eliminate mosquito-breeding sites around the home. They can remove standing water in potted plants, tires, bird baths and other containers where water may collect; remove unnecessary clutter; repair window and door screens to keep mosquitoes out of the home and make sure pools and decorative ponds are properly maintained and operational.
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