Health officials report that symptoms of West Nile virus can appear three to 14 days after infection.
WELD COUNTY, Colo. — Health officials in Weld County reported that mosquitoes in two parts of the county tested positive for West Nile virus.
The two areas that tested positive are being tested regularly, the Weld County Public Health Department said.
The areas where the mosquitoes were caught were in the Johnstown, Milliken and Platteville zone, and the other zone was in the Firestone, Dacono and Fort Lupton zone, officials said. Mosquitoes caught in the Greeley, Evans, Kersey and LaSalle zones did not test positive for the virus.
> Video above: 9NEWS health expert Dr. Payal Kohli talks about the growing concerns about West Nile virus infections.
Health officials in Weld said no human cases of West Nile virus have been reported, but populations of the mosquitoes that transmit the virus are increasing.
“Increasing warm weather often creates favorable conditions for the Culex mosquito, which transmits West Nile virus,” said Jason Chessher, director of the Weld County Health Department. “The public should be vigilant as West Nile virus has a permanent summer presence in Colorado.”
Symptoms of West Nile virus usually appear three days to two weeks after a person becomes infected.
- Fever
- Headache
- Nausea and vomiting
- Muscle pain and weakness
- Rash
If people develop symptoms, they are urged to seek immediate medical attention, the Weld County Public Health Department said.
Officials said most infected people do not show symptoms. Less than 1% of those infected develop a serious neuroinvasive disease that can sometimes lead to death.
People can limit their exposure to mosquitoes that transmit viruses by observing the four “D’s”:
- DRAINAGE standing water around your home weekly. Don’t forget to drain water from tires, cans, flower pots, clogged gutters, rain barrels, toys and puddles.
- Dusk and Dawn are the times when mosquitoes are most active. Limit outdoor activities and take precautions to avoid mosquito bites during these times.
- DEET is an effective ingredient to look for in insect repellents. Other repellents containing picaridin, IR3535, oil of lemon eucalyptus, or para-menthanediol are also effective against mosquitoes. Always follow the instructions on the product label carefully.
- DRESS Wear long sleeves, long pants, and a hat in areas with high mosquito density.
The first human case of West Nile was confirmed in Colorado late last month.
Last year, Colorado was the state with the highest number of West Nile virus cases.