This week the Larimer County Department of Health and Environment received a report of Larimer County’s first positive human test for West Nile virus in a blood donor from southeast Fort Collins.  So far, the donor is asymptomatic.  Blood donations that test positive for West Nile are discarded and are not used for transfusions. Positive tests in blood donors provide timely warning of increasing West Nile risks to Larimer County residents. 

Trapping of mosquitoes to monitor for West Nile virus risk began in June in Larimer County.  West Nile disease is a viral infection which is spread to people by bites from infected Culex mosquitoes.  Symptoms can range from none at all to severe illness.  About 75% of people who are infected are asymptomatic; about 25% will develop West Nile fever.  Less than 1% develop the more severe neuroinvasive form, which can lead to hospitalization, critical illness, chronic disability, or even death.  

Larimer County Department of Health and Environment works with cities, Vector Disease Control, International (formerly Colorado Mosquito Control, Inc), and Colorado State University to monitor and assess the risk to Larimer County residents. 

West Nile virus can be prevented. In addition to community efforts, such as larviciding, reducing water where mosquitoes can breed, and spraying for adult mosquitoes, individuals can remember to use the 4 D’s to help prevent West Nile virus disease:

  • DEET or other effective mosquito repellent - Use an EPA-registered mosquito repellent that has been proven to be effective against West Nile virus-carrying mosquitoes.  DEET, Picaridin, Oil of Lemon Eucalyptus (also called p-menthane-3,8-diol or PMD) and IR3535 are good choices.
  • Dusk to Dawn - Avoid exposure during peak Culex mosquito feeding times, from dusk through dawn. 
  • Dress - Wear long sleeves and pants to keep mosquitoes from biting.
  • Drain – Remove standing water in your yard or garden to minimize mosquito breeding areas.

For more tips on what you can do to prevent West Nile virus, visit Larimer.org/westnile

Published on: 
Monday, July 31, 2017 - 6:00pm
Contact Details:

Katie O'Donnell

I Want To

Larimer County, Colorado

200 W. Oak Street
Fort Collins, CO 80521
Map of Facilities

Connect with Us

Larimer County on Facebook Larimer County on Twitter Larimer County on YouTube Larimer County on LinkedIn Email subscription
Transparency  |  Accessibility
Legal Disclaimers
Website Feedback Website Feedback
US FlagHalfColorado FlagHalf
Top of Page