PHOENIX (AP) -- Maricopa County officials have confirmed the year's first positive mosquito sample, marking an early start to the West Nile virus season.
The county's Environmental Services Department reported mosquito traps had an increased number of mosquitoes last week with one sample testing positive for West Nile.
Maricopa County just experienced a wet winter and as nighttime temperatures get warmer, authorities say there likely will be increased mosquito activity.
Last year, Maricopa County reported 168 positive mosquito samples and 76 lab-confirmed human cases with two reported deaths. According to the CDC, there were more than 3,500 case of West Nile virus nationwide.
Experts say homeowners can prevent the problem by eliminating breeding sites in their yards, including standing water in potted plants, tires, bird baths and other containers where water may collect.
They also say backyard pools and decorative ponds need to be properly maintained.
West Nile virus was first reported in the U.S. in 1999. The first cases were in New York, but over the years, the mosquito-born disease spread across the U.S., showing up in Arizona in 2003.
To report mosquitoes in Maricopa County, contact Environmental Services at 602-506-0700 or online at maricopa.gov/wnv.