Colorado has seen a sharp increase in the number of cases of West Nile virus diagnosed in 2016. People, animals and mosquito pools have tested positive from the following counties this season: Adams, Arapahoe, Bent, Boulder, Denver, Douglas, El Paso, Gunnison, La Plata, Larimer, Mesa, Morgan, Rio Blanco and Weld. So far this year, 13 cases of human West Nile virus have been reported, including one death.

The Colorado Department of Public Health and Environment expects more cases to be diagnosed as the summer progresses. Public health officials advise Colorado residents to continue to take precautions against West Nile virus by using mosquito repellent and other methods to avoid mosquito bites. Last year, 101 people in Colorado contracted West Nile virus, and three died.

“Although we can't predict how much more West Nile virus activity will occur this summer, we know the virus is present, and that means people are at risk,” said Jennifer House, state public health veterinarian.

To help prevent West Nile virus infection, follow the four D’s:

•DRAIN standing water around your house weekly. Remember to drain water from tires, cans, flowerpots, clogged rain gutters, rain barrels, toys and puddles.

•DUSK and DAWN are when mosquitoes are most active. Limit outdoor activities and take precautions to prevent mosquito bites during these times.

•DEET is an effective ingredient to look for in insect repellents. Always follow label instructions carefully.

•DRESS in long sleeves and pants in areas where mosquitoes are active.

For more information about West Nile virus, visit the department’s West Nile virus page.