Battle of the bugs: preventing West Nile | PostIndependent.com

Battle of the bugs: preventing West Nile

Donna Gray
Post Independent Staff

Mosquito numbers are up in Garfield County, according to Colorado Mosquito Control, which keeps count and has mounted a treatment campaign to keep West Nile virus at bay.

Because of springtime and recent rains, places that were dry last year are now wet and some are harboring hefty mosquito populations, said Tony Stillwell, of Colorado Mosquito Control.

As of July 15, there have been 10 human cases of the virus in the state. Two birds have tested positive in the state, one in Aspen. One death has been reported in the U.S., in Missouri.

Garfield County has remained untouched with no human, horse, birds or mosquitoes testing positive for the disease.

West Nile virus in humans can lead to meningitis, an infection of the spinal fluid, or the sometimes-fatal encephalitis, an inflammation of the brain.

In 2004, Colorado had the highest number of people with the disease in the nation, with 271 reported cases and three deaths. Garfield County’s mosquito control program helped keep the numbers of cases down to four last year, while neighboring Mesa County had the highest in the state, with more than 200 cases and three deaths. No one died in Garfield County.

Heavy rains last week created ideal conditions for breeding mosquitoes, as have irrigated fields across the county, Stillwell said. Traps have also shown higher numbers of Culex tarsalis, the mosquito species that carries West Nile virus.

This year Colorado Mosquito Control has treated 300 acres with larvacide compared to 200 acres last year, Stillwell said.

Colorado Mosquito Control has also sprayed in areas of New Castle, Rifle, Battlement Mesa and Parachute. It has also concentrated on spraying before special events such as Grand Valley Days in Parachute. Town manager Juanita Satterfield said mosquitoes were not a problem during the weekend festival. Colorado Mosquito Control will also spray before Carbondale Mountain Fair this weekend and the Garfield County Fair, Aug. 9-13.

Stillwell also pointed out that spreading larvacide is by far the most effective way to treat mosquitoes. It will kill up to 90 percent of a population in a pond. Spraying kills only a small percentage.

“With (spraying) you’re really just thinning the herd,” Stillwell said. Effects only last four or five days, then another wave of mosquitoes comes in again. Colorado Mosquito Control will spray private land within its 50-square-mile service area around the county’s towns and cities. To schedule an appointment call Cynthia Page, operations manager in Glenwood Springs, 989-0083.

No matter the method of treatment, people still need to take precautions, said Tom Whitmore, director of parks for the city of Rifle.

Stillwell said it’s important for people to remain vigilant against mosquitoes, especially in the next two months when the disease historically has shown up.

“We’re not through the season yet,” he said.

It’s hard to predict how severe the disease will be in a given year.

“West Nile is a roller-coaster disease. It comes in and hits hard and then drops off and then hits again,” Stillwell said.


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