It’s been 20 years since Maricopa County had its first West Nile virus outbreak. In 2021, the county had its worst outbreak that resulted in 101 deaths. West Nile is the most common mosquito-borne disease in Arizona and the U.S.
James Will, managing supervisor for Maricopa County Vector Control, said mosquitos only need a little water to lay eggs.
“We found mosquitoes breeding in bottle cap tops, you know, so you just need to look around your house, look at gutters, pet toys, kids' toys, anything that collects water, plants, planters that, you know, you fill up the bottom and that kind of soaks up the water to the plant. You want to make sure you clean those out, wipe them out, weekly,” he said.
The Centers for Disease Control and Prevention say most infected people do not feel sick and about one in five who are infected develop flu-like symptoms, while one in 150 develop a serious, sometimes fatal, illness.
“It needs to be taken seriously because it's, you know, for the people that get it, it can have devastating outcomes,” Will said. “You can get meningitis, encephalitis, you know, all the way to unfortunately death.”
There are no vaccines for the West Nile virus, which can also affect dogs, cats, horses and other animals.
While mosquitos bite anytime, they can be especially active between dusk and dawn. To prevent bites, people can wear long sleeves and pants and insect repellant.
Will said Maricopa County has 27 inspectors looking at sites that breed mosquitos.
“We have over 4,000 sites a month that we treat that are known mosquito breeding sites,” he said. “We also take care of complaints that call in. If they call in a complaint for mosquitoes, we go around the neighborhoods and try to find any kind of areas where we find mosquitoes breeding.”
The county sets hundreds of traps to test mosquitoes for disease and positives results lead to a process called fogging, which takes place between midnight and 5 a.m.
“We use EPA registered chemicals and they're loaded into a truck. We have a fog around the back of a pickup truck and that truck will drive through the neighborhood at about 15 miles per hour,” Will said. “It sprays a fog out the back of it. And that fog is intended to do about a 300-foot swath for mosquitoes, and that fog, as it goes through the air, the droplets, if it touches a mosquito, it kills that mosquito.”
EDITOR'S NOTE: This story has been updated to clarify West Nile is the most common mosquito-borne disease in Arizona and the U.S.
