The first two human cases of West Nile virus in Colorado in 2018 have been reported in Weld and Delta counties. The Colorado Department of Public Health and Environment reminds people that preventing mosquito bites is the No. 1 way to avoid getting any mosquito-borne illness.
Weekly mosquito testing for West Nile virus began statewide in June. Adult mosquitoes are trapped and tested to provide an estimate of the number that are infected. The results help pinpoint the risk to humans in the area. Most human West Nile virus cases are reported in August and September.
"When the virus is present, people are at risk," said Jennifer House, state public health veterinarian. "Use an effective insect repellent, wear protective clothing or stay indoors when mosquitoes are active, and mosquito-proof your home."
In 2017, there were 68 human cases of West Nile virus in Colorado, including four deaths.
Most people who are infected with West Nile virus don't have symptoms. About 20 percent have flu-like symptoms, and fewer than 1 percent develop a serious, potentially deadly illness. People over age 60 and those with certain medical conditions are at greater risk of serious illness. See a health care provider if you develop severe headaches or confusion.