Adams County Health Department officials confirmed the first two human cases of West Nile Virus this year, likely contracted from infected mosquitos in late June.

Neighboring counties have reported mosquitoes that tested positive for the virus, however ACHD has not found the virus in Adams County mosquitoes this year in its seasonal testing.

So far in 2025, Arapahoe, Boulder, Denver, Larimer, and Weld counties have found mosquitos infected with the virus, according to their respective health agencies.

Dr. Kelly Weidenbach, executive director of the Adams County Health Department, encourages residents to take precautions to themself from WNV.

“The virus is transmitted through mosquito bites,” Weidenbach said. “To protect against it, we suggest using effective insect repellents, wearing protective clothing to minimize exposed skin, or opt to stay indoors during peak mosquito activity.”

According to ACHD, most people infected with the West Nile virus don’t experience symptoms.

About 20% of infected people will have flu-like symptoms, and fewer than 1% develop a serious, potentially deadly illness, the county said.

Those aged 60 and older with certain medical conditions are at a higher risk of developing serious illness. Adams County is urging people to seek medical care if they develop severe headaches or begin experiencing confusion.

To protect against the virus, health officials advise to:

• 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.
• Limit outdoor activities at dusk and dawn, as mosquitos are most active during this time.
• Wear long pants and shirts that cover the skin.
• Empty standing water around your house to prevent mosquitos from congregating.
• Install or repair screens on windows and doors to protect your home.

ACHD is distributing free insect repellent wipes containing picaridin at its Westminster clinic (1401 W. 122nd Ave., #200, Westminster), and at various other community outreach events throughout the summer or until supplies last.

For more information, visit the Colorado Department of Public Health and Environment’s West Nile virus webpage.