Watch out for West Nile Virus in Garfield County |

Watch out for West Nile Virus in Garfield County

Baron Zahuranec
Rifle Correspondent
Glenwood Springs, CO Colorado

The West Nile virus, carried by Culex tarsalis mosquitoes, can be a debilitating thing to catch; possible paralysis, meningitis, or swelling of the brain’s lining, and in severe cases, death.

So how worried do Garfield County residents need to be? With this year’s higher than average snowpack in the mountains, county Vegetation Manager Steve Anthony speculates there will be many more breeding areas because of more standing water, compared to past years.

“There’s usually around five reported cases of West Nile virus in this county each summer,” Anthony said.

Many of the cases tend to be reported after Aug. 1 as the initial symptoms of West Nile are quite flu-like: Fever, head and body aches, and swollen lymph nodes.

People think they just have the flu and don’t go to the doctor to get checked out.

When a few weeks pass and the symptoms haven’t subsided, that’s when they go in for a check up, Anthony said.

To help keep an eye on the mosquitoes, the county, Rifle, Parachute, Silt, New Castle, Glenwood Springs and Carbondale are now in their fifth year of trapping and recording mosquito numbers, through a contract with Colorado Mosquito Control.

Special traps are set up at various locations throughout the towns and outlying areas and are checked once a week. Each individual mosquito is counted and once a “pool” of 50 Culex mosquitoes are collected, they are sent to the Colorado Department of Public Health and Environment Labs for West Nile virus testing.

Several methods are available for sampling adult mosquitoes. Center for Disease Control, or CDC, light traps are the most common and are used in most Colorado Mosquito Control programs.

The traps are used to capture nocturnal mosquitoes that are attracted by carbon dioxide, or CO2, and light. A CDC trap consists of a canister that emits CO2, a small incandescent bulb to attract the mosquitoes, and a fan to force them down into a mesh net.

The adult mosquitoes are then sorted to sex and species and counted, with the results entered into the computer for trend analysis. Season-long trapping results can be used to identify population trends, component species and to effectively time spray applications. Other techniques include sweep netting vegetation and taking landing and biting counts.

Early trapping results could point to a busy West Nile summer this year. In Rifle, the Mile Pond Road trap caught 1,500 mosquitoes when it was checked on June 25. One percent were Culex mosquitoes, or 15 out of 1,500.

“That’s a lot for any of our traps. There must be a good breeding ground out there for them,” Anthony said.

To give an idea of how many mosquitoes can hatch from a small area of standing water, “one coffee can can breed 10,000 mosquitoes during a season over four to six hatchings,” Anthony said.

The best way to try and keep yourself safe is to limit outdoor activity in the morning and evening hours and to wear long sleeves and pants, Anthony said.

For more protection, “use a repellent of your choice,” he said. “You have your choice of organic kinds or ones with DEET. I like to use BiteBlocker. I’d just like to ask that the public take care of themselves this summer.”

Contact Baron Zahuranec at 384-9173

Support Local Journalism

Support Local Journalism

Readers around Glenwood Springs and Garfield County make the Post Independent’s work possible. Your financial contribution supports our efforts to deliver quality, locally relevant journalism.

Now more than ever, your support is critical to help us keep our community informed about the evolving coronavirus pandemic and the impact it is having locally. Every contribution, however large or small, will make a difference.

Each donation will be used exclusively for the development and creation of increased news coverage.


Start a dialogue, stay on topic and be civil.
If you don't follow the rules, your comment may be deleted.

User Legend: iconModerator iconTrusted User