With summer in full swing, Coloradans can expect a few days of 100 degree heat, increased traffic near reservoirs, and, unfortunately, mosquitoes. And with the pests comes an increased number of positive tests for the West Nile virus.
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Boulder County is the latest to share results of mosquitoes testing positive for the virus. Boulder County Public Health said the bugs came from a trap in Niwot East last week. It’s the first positive case they’ve found in the county so far, but the virus hasn’t only appeared in Boulder County.
Larimer County reported a sample of mosquitoes from southeast Fort Collins testing positive in mid-June. On Monday, Weld County health officials announced that mosquitoes in two of their testing zones have also tested positive for West Nile. This includes Zone 1 (Greeley, Evans, Kersey, and LaSalle areas) and Zone 2 (Firestone, Dacono, and Fort Lupton areas).
The West Nile Virus is usually carried by the Culex mosquito. The bug can transmit the virus to someone it bites. BCPH officials say symptoms include “fever, fatigue, headache, body aches and sometimes rash or swollen lymph nodes.” It generally takes three to 14 days for symptoms to appear. Most West Nile cases are mild but it can lead to serious health issues and occasionally death.
According to a map from the Centers for Disease Control, last year in Colorado, Larimer County had five human cases, Weld County saw 15 and Boulder County reported nine. Those numbers can change dramatically depending on the year. For instance, in 2023, Larimer County had 52 cases, Weld had 53 and Boulder County counted 29.
While there are no positive cases of people with West Nile in the state so far, health officials warn that could soon change.
“We’ve seen low numbers of mosquitoes so far, but we expect them to increase as the season goes on,” said Marshall Lipps, Environmental Health Specialist at Boulder County Public Health, in a press release. “However, West Nile virus transmission risk still exists in Boulder County and surrounding areas, and we encourage the community to take personal precautions to prevent mosquito bites.”
According to the CDC, the best way to avoid the West Nile virus is to reduce contact with mosquitoes. That includes:
- Using insect repellent
- Wearing long-sleeved shirts and pants
- Treating clothing and gear
- Taking steps to control mosquitoes indoors and outdoors
