First human case of West Nile reported: take precautions to avoid bites

Mark Salley, Communications Director | 303-692-2013 |


DENVER —As you head out for summer holiday celebrations, remember to take along insect repellent to protect yourself against West Nile virus. There has been one human case of the disease reported in Colorado so far this year.
Weekly mosquito testing for West Nile virus began statewide June 12. Adult mosquitoes are trapped and tested to provide an estimate of the number of infected mosquitoes. The results detect West Nile virus risk to humans in the area. West Nile virus-positive mosquitoes have been found in Larimer County this season. Not all counties and municipalities test mosquitoes, so it’s important for all Coloradans to take preventative steps throughout the summer. 
“When the virus is present, people are at risk,” said Jennifer House, state public health veterinarian. “Protecting yourself from mosquito bites is the No. 1 way to avoid getting any mosquito-borne illness. Use an effective insect repellent, wear protective clothing or stay indoors when mosquitoes are active, and mosquito-proof your home.”
In 2016, there were 149 human cases of West Nile virus in Colorado, including 8 deaths.
Most people who are infected with West Nile virus don’t have symptoms. About 20 percent have flu-like symptoms, and fewer than one percent develop a serious, potentially deadly illness. People over age 60 and those with certain medical conditions are at greater risk of serious illness. See a health care provider if you develop severe headaches or confusion.
            To protect yourself:
  • Use insect repellents when you go outdoors. Repellents containing DEET, picaridin, IR3535, and some oil of lemon eucalyptus and para-menthane-diol products provide the best protection. Follow label instructions.
  • Limit outdoor activities at dusk and dawn, when mosquitoes that carry West Nile virus are most active.
  • Wear protective clothing (long pants, long-sleeved shirts and socks) in areas where mosquitoes are active. Spray clothes with insect repellent for extra protection.
            To mosquito-proof your home:
  • Drain standing water around your house often. Empty water from tires, cans, flowerpots, clogged gutters, rain barrels, birdbaths, toys and puddles.
  • Install or repair screens on windows and doors.
For more information, visit the department’s West Nile virus web page. Check for human case numbers and mosquito trap results on the West Nile virus data page throughout the season.