The West Nile virus has arrived with a vengeance along with the summer rain.
Already this season, 13 cases of the deadly mosquito-borne disease have been confirmed statewide, including 11 in Maricopa County and another in Pinal County.
Most were reported in the last two weeks, scattered from the far East Valley to the northwest side. Those who fell ill range in age from their 40s to their 80s, and some people remain hospitalized.
“It’s gone up pretty quickly with the human cases,” said John Townsend, the county’s vector control manager. “It’s a lot earlier. At least we don’t have any fatalities. But we do have 11 humans, which is 11 more than we had this time last year.”
Townsend’s office is fielding about 200 to 300 complaints a week, but he expects those numbers to skyrocket once a big storm dumps on the area.
But don’t blame those floodwater mosquitoes for West Nile. It’s another species — the culex mosquito — that carries the virus, and they’re most likely to breed in backyards and feed during the night.
“The ones everybody complains about are the floodwater mosquitoes, who bite you in the daytime and create a big nuisance,” Townsend said. “But they’re not the ones you have to worry about.”
Townsend’s crews check traps in about 500 locations, and investigate areas where West Nile cases have been confirmed. Traps throughout the Valley have collected hundreds of culex moquitoes, some of them carrying West Nile. Just 30 culex mosquitoes are enough to send trucks to a neighborhod for insecticide fogging and possible larvicide treatment.
Wednesday evening, for example, two Queen Creek locations were fogged because West Nile moquitoes had been trapped there. Crews will fog in Scottsdale’s McCormick Ranch area Thursday night for the same reason.
This season’s early start doesn’t necessarily mean it will be a bad year, but health officials urge residents to check for breeding sources outside and inside, and take precautions, like wearing mosquito repellant and limiting outdoor activity during dusk and dawn.
Though West Nile cases came late last summer, like the rains, by October the virus had infected 150 people and killed six county residents and 11 across the state.
In 2005, there were 106 human cases and four deaths; and 391 cases, with 16 deaths, in 2004.
Most people bitten by infected mosquitoes won’t develop any symptoms, about 20 percent will develop flulike symptoms and fewer than 1 percent develop encephalitis.
Those most at risk are the elderly and people with compromised immune systems.
Protecting yourself from West Nile
FOGGING: Maricopa County Environmental Services will fog the following areas for mosquitoes from 10 p.m. today to 5 a.m. Friday:
• Via Linda, just south of Mountain View Park, to Via de Ventura, and Gainey Ranch Road, near Rotary Park, to Pima Road.
INFORMATION: For information or to report a mosquito problem or get free mosquito-eating fish, contact Maricopa County Vector Control, (602) 506-0700, or go to www.maricopa.gov/wnv.
• You can also find information online at www.westnileaz.com or call a 24-hour hot line at (800) 314-9243 or (602) 364-4500.
In your yard:
• Don’t allow water to stand for more than two days.
• Check for standing water in birdbaths, pet dishes, buckets, cans, outdoor toys, wheelbarrows, old tires, boats and flowerpots.
• Remove any water that collects on pool covers.
• Clear leaves and twigs from eaves, troughs and gutters.
• Fill in low areas in lawns.
• Repair leaky pipes and outside faucets, as well as damaged window and door screens.
• Let neighbors know about potential mosquito-breeding grounds on their property, or report stagnant water to the county at (602) 506-6616.
To reduce the chances of being bitten:
• Stay indoors from dusk to dawn, when mosquitoes are most active.
• Wear loose-fitting clothing, long sleeves and long pants.
• Apply insect repellent containing DEET to clothing as well as exposed skin.
• Do not use insect repellent on children younger than 2.