Wednesday, July 27th - More Mosquitoes Increases Risk Of West Nile Virus...

The Larimer County Department of Health and Environment reports that the number of Culex mosquitoes (the primary species that transmits West Nile virus in Colorado), has increased sharply in the past two weeks.  “There are now hundreds of mosquitoes being trapped in a number of locations throughout the county, whereas fewer than 100 were typically trapped in most locations prior to the recent hot temperatures, said Dr. Adrienne LeBailly, Health Department Director.  “We have also had one mosquito “pool”—a collection of about 50 mosquitoes from one trap, with at least one infected mosquito—test positive for West Nile Virus in Larimer County.” 

So far, there has been only one confirmed human case of West Nile virus in Larimer County, and a total of 10 human cases statewide.   No birds and no horses have been reported as infected in the county, but statewide 2 birds and 3 horses have tested positive for West Nile, as well as two mosquito pools in Pueblo County.

Dr. LeBailly explained, “It is important for residents and visitors to Larimer County to take action to protect themselves from mosquito bites.  “These are similar weather conditions to what we had when West Nile exploded in Larimer County in 2003.  While we may not have as much virus here this year, it’s impossible to predict, and people should be extra careful over the next couple of weeks as we watch to see how things evolve.”

The most effective way to prevent mosquito bites is to use an effective mosquito repellent.  Prior to 2005, only products containing DEET were recommended by the CDC (Centers for Disease Control and Prevention) as safe and effective to prevent West Nile virus infection.  In April, the CDC announced that two additional products had been added to list of EPA (Environmental Protection Agency) approved mosquito repellents.

The new products now available in the U.S., include Cutter Advanced, which contains the active ingredient, picaridin (KBR 3023), and OFF! Botanicals which contains the active ingredient, oil of lemon eucalyptus.  Both products provide protection similar to low concentrations of DEET.  Oil of lemon eucalyptus has not been approved for children under 3 years of age.  These new products as well as DEET should not be used for infants under 2 months of age according to recommendations from the American Academy of Pediatrics.  Various kinds of netting can be used to protect infants such as netting for strollers and playpens.

“The variety of products now available provide a range of alternatives to accommodate individual preferences, said LeBailly.  “Products containing 23% DEET have been shown to protect for 5 hours in rigorous research studies.  For shorter exposure times, products with as little as 6% DEET protect for 2 hours.”

Repellents are available in aerosol cans, non-aerosol pump sprays, lotions, towelettes; scented and unscented.  “The important point is to find a repellent that you like and always remember to use it when you are out of doors.” said LeBailly

For detailed information about various products, visit the Health Department’s web site at www.larimer.org/health , www.healthinfosource.com, or www.fightthebitecolorado.com

Tips for proper repellent use:

§  Your backyard or patio is not a “safe zone.”  Even a brief trip out to the barbecue or garden allows time for an infected mosquito to bite.

§  Use enough repellent to cover exposed skin or clothing.  Don’t apply repellent to skin that is under clothing.  Heavy application is not necessary to achieve protection.

§  Do not apply repellent to cuts, wounds or irritated skin.

§  After returning indoors, wash treated skin with soap and water.

§  Do not spray aerosol or pump products in enclosed areas.

§  Do not apply aerosol or pump products directly to the face.  Spray hands and then rub them carefully over the face, avoiding the eyes and mouth.

Guidelines for Children and Repellents

• Use products containing 10-to-30 percent DEET or less for children.
• Parents should apply repellent to young children to insure complete coverage and proper application.  Avoid getting the repellent on children’s hands or in their eyes or mouths.
• Repellents containing DEET should not be used on children two months of age and younger.  Limiting exposure to mosquitoes is best for these infants.
• Mosquito netting products are available to fit over strollers or baby cribs.
• Insect repellent applied to protective clothing is also effective.
• Clothing can be sprayed with insecticides or repellents containing Permethrin or DEET. Treated clothing can be purchased.  Such clothing will last through several launderings. Do not spray Permethrin directly on skin.  Follow product directions.

§  If you will not use repellents, use alternative means of protection.  These include wearing long-sleeved shirts and long pants, covering your face with mosquito net hoods.  Cover baby strollers or playpens with mosquito netting.

The Health Department is continuing to monitor numbers and species of mosquitoes and signs of the infection in birds and horses. Colorado Mosquito Control has been contracted to conduct mosquito surveillance and control activities for parts of the county and for Fort Collins, Loveland and some home owner’s associations.

Back to Main News