By Shannon Lukens.
Four Colorado counties have now had positive tests for mosquitos with the West Nile Virus. They are Boulder, Delta, Weld, and Larimer. West Nile Virus can be serious, and deadly. There were 206 cases in Colorado last year and 20 people died. Limit outdoor activity at dusk and dawn when mosquitos are more active, and use insect repellent.
Press release from the Colorado Department of Public Health and Environment; July 6, 2023.
Mosquitoes in four Colorado counties test positive for West Nile virus
STATEWIDE (July 6, 2023) — State health officials are reminding Coloradans to take steps to protect themselves from West Nile virus after finding mosquitoes with the virus in Boulder, Delta, Weld, and Larimer counties. This is the first time this season that mosquitoes with the virus have been detected in Colorado. Local health officials in all four counties found the mosquitoes during routine monitoring for West Nile virus. Some local health agencies, including in Boulder, Delta, Weld, and Larimer counties, test mosquitoes for West Nile virus throughout the summer when mosquito activity is highest in Colorado.
While most people infected with West Nile virus don’t have symptoms, some can develop a serious, potentially deadly illness. In 2022, Colorado had 206 reported human cases of West Nile virus, including 20 deaths. People aged 60 years and older and those with certain medical conditions are at greater risk of serious illness. Talk with a health care provider if you develop severe headaches or begin experiencing confusion.
West Nile virus is most commonly spread to people by the bite of an infected mosquito. In Colorado, most human cases of West Nile virus are reported in August and September. To protect yourself:
- Use insect repellents when you go outdoors. Repellents containing DEET, picaridin, IR3535, oil of lemon eucalyptus, or para-menthane-diol products provide the best protection. For more information about insect repellents, visit the EPA’s information webpage. Always follow label instructions.
- Limit outdoor activities at dusk and dawn, when mosquitoes are most active.
- Wear long pants, long-sleeved shirts, and socks in areas where mosquitoes are active. Spray clothes with insect repellent for extra protection.
In addition to eliminating standing water around your home weekly, you can also mosquito-proof your home by installing or repairing screens on windows and doors.
You can find additional data going back to 2003 on CDPHE’s West Nile virus webpage, which is updated weekly throughout the season.