DDPHE Urges Caution as West Nile Virus Case Confirmed in Denver

Published on August 16, 2024

The Denver Department of Public Health & Environment (DDPHE) is urging residents to take caution after DDPHE disease intervention specialists confirmed the first human case of West Nile virus in a Denver resident.

West Nile virus is most commonly spread to people from the bite of an infected mosquito. The virus is not spread through person-to-person transmission. 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.

DDPHE recommends residents do their part and help protect the community against West Nile virus by taking the following precautions:

  • Stop mosquitoes from laying eggs in or near water on your property.
    • Once a week, empty and scrub, turn over, cover, or throw out items that hold water, such as tires, buckets, planters, toys, wheelbarrows, pools, birdbaths, flowerpots, or trash containers.
    • Check for water-holding containers both indoors and outdoors.
    • Do not water your cement or the street. It can result in pools that support larval mosquitoes.
    • If you are making landscape decisions, consider ways to minimize overspray (of irrigation) to streets and gutters.
  • Use Environmental Protection Agency (EPA)-registered insect repellents with DEET. When used as directed, EPA-registered insect repellents are proven safe and effective, even for pregnant and breastfeeding women.
  • Avoid activity outdoors at dusk and dawn, when mosquitos are most active.
  • When outdoors, wear loose-fitting, long-sleeved shirts and pants.
  • Use mosquito repellent as well as candles, incense, and other means to deter mosquitos from your vicinity.
  • Use screens on windows and doors. Repair holes in screens to keep mosquitoes outdoors.

While everyone is at risk of being infected with West Nile virus, those over 50 years old, or with weakened immune systems, are at greater risk of developing serious illness. Symptoms of West Nile virus typically include fever, extreme fatigue, headache, body aches, but can also occasionally include skin rashes and swollen lymph nodes. Symptoms generally appear three to 14 days after being bitten by an infected mosquito. While most infections are mild, 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 even death.

Denver residents who experience these symptoms should consult their doctor. There is no treatment, cure, or human vaccination for the virus, but medical professionals can treat symptoms to help patients feel better and possibly recover more quickly.

For more information about West Nile virus in Colorado or mosquito activity data, visit the CDPHE website. Learn more about how Denver manages the mosquito population in the DDPHE Environmental What If podcast.