Boulder County, Colo. - Boulder County Public Health has confirmed that three county residents have contracted West Nile virus – a 74-year-old Lafayette woman, a 47-year-old north Boulder man, and a 13-year-old Longmont boy. They are the first three people in the county to contract the virus in 2016.

All three residents reported fever, headache, muscle weakness, and severe fatigue. One person also reported a rash, eye pain, and joint pain, and another reported nausea. None of the residents were hospitalized. Symptoms of West Nile virus will typically include fever, extreme fatigue, headache, body aches, but can occasionally also include skin rashes and swollen lymph nodes. Symptoms generally appear 3-14 days after being bitten by an infected mosquito.

West Nile virus is transmitted to humans from the bite of an infected mosquito. While most infections are mild, the more serious infections can cause encephalitis (inflammation of the brain) and/or meningitis (inflammation of the brain's lining), loss of vision, paralysis, coma, tremors, convulsions, and death.

While everyone is at risk of being infected with West Nile virus, those over the age of 50 or with weakened immune systems are at greater risk of developing serious illness. Anyone who experiences these symptoms should consult their health care provider. There is no treatment, cure, or human vaccination for the virus, but health care providers can treat symptoms to help patients feel better and possibly recover more quickly.

In Colorado, most West Nile virus cases are diagnosed in August and September, but cases can be identified as early as May and as late as December. Generally, the mosquito season extends from late April until mid-October, with the end usually signaled by the first freeze in the fall.

“Although the Zika virus has been in the news lately, West Nile virus is a more serious issue in our region,” said Boulder County Public Health Regional Epidemiologist Kylie Chilton. “The 4Ds to protect you against West Nile are the same as the steps people should take to protect themselves from Zika virus,” Chilton said.

Boulder County Public Health officials urge residents to remember the 4Ds:

1. Use DEET-enhanced insect repellent or alternative.
2. DRESS in long sleeves and pants.
3. Avoid the outdoors from DUSK until DAWN.
4. DRAIN standing water outside your home.

For more information about West Nile virus, mosquito activity in Boulder County, or proactive steps to take, visit www.BoulderCountyMosquito.net or call the Colorado Health Information Line at 1-877-462-2911.