First West Nile Virus-Infected Mosquito Confirmed In Larimer County

Ruzanna Harutyunyan's picture

The Larimer County Department of Health and Environment reported that a mosquito carrying West Nile virus was trapped on June 5, making it the first positive sample in Larimer County and in Colorado for 2009. The positive trap was from Fort Collins, near Lemay and Riverside.

This positive trap is the earliest ever reported in Larimer County, 3-5 weeks earlier than most years. It is usually July when West Nile Virus infections in Culex mosquitoes are first identified in area traps. Culex mosquitoes are the species that spread West Nile Virus to humans.

“Although the number of mosquitoes is low so far this year, this positive trap confirms that the risk of West Nile infection is present even in June.” said Dr. Adrienne LeBailly, director of the Larimer County Health Department. “This is a timely reminder of the things we all can do to lower our risk of getting sick.”

At highest risk of serious illness from West Nile infection are people over 50, solid organ transplant recipients, people undergoing cancer treatment, or anyone with a weakened immune system. However, all persons who are not adequately protected from mosquito bites are at risk of being bitten and infected by a West Nile virus-carrying mosquito.


To protect yourself from mosquito bites, the health department recommends the following:

* Use a mosquito repellent that has been proven to be effective against West Nile Virus-carrying mosquitoes. Ones that contain DEET, Picaridin, Oil of Lemon Eucalyptus (with active ingredient PMD, or p-menthane diol) or IR3535 are good choices.

* Keep exposed skin covered or use a repellent when out at prime Culex mosquito-biting hours, between dusk and dawn.

* Drain standing water in your yard or in your garden.

* Add mosquito-eating minnows to or a mosquito “dunk” to ornamental ponds that feature still water.

* Keep window screens repaired.