NewsLocal News


West Nile virus in Denver: Officials urge caution as health department investigates 6 suspected cases

One person has died after contracting West Nile virus in Colorado and more than 10 have been hospitalized so far this year
Mosquitoes in Longmont test positive for West Nile Virus
Posted at 11:37 AM, Aug 10, 2023
and last updated 2023-08-10 13:37:38-04

DENVER – Denver health officials are urging residents to take precautions as they investigate at least six suspected cases of West Nile virus in the community.

Bob McDonald, the head of the Denver Department of Public Health and Environment (DDPHE), said in a news release Thursday health officials have seen “extremely high levels of mosquito activity in our region this summer,” when compared to trends that have been reported at the local and state level over the past 20 years.

Health experts Denver7 has spoken with since the beginning of July said the boom in Culex mosquito populations the state has seen this year were likely the result of a wet and cool spring as well as early summer rainfall that has come down over the Front Range.

So far, at least one person in the state has died from complications after contracting West Nile virus and 22 others have been affected by the disease, with nearly half of those requiring hospitalization, according to state data.

“It’s extremely important to take extra precautions to protect yourself, your family, and neighbors, especially if you’re spending time outdoors in the morning or evening," McDonald said.

How to protect yourself and your family from West Nile virus

Mosquitoes are most active at dusk and dawn, so the first line of defense against potential exposure is to avoid activities during this time, according to health experts.

As mosquito season continues, health officials recommend taking the following steps to protect yourself and your family from West Nile virus:

  • Stop mosquitoes from laying eggs in or near water on your property by:
    • Eliminating sources of standing water near your home by emptying, scrubbing, turning over, covering or throwing out items that hold water such as tires, buckets, planters, toys, wheelbarrows, pools, birdbaths, flowerpots, or trash containers once a week. All of these can become a breeding ground for the mosquitoes that carry West Nile virus
    • Check for water-holding containers both indoors and outdoors
    • Avoid watering cement or on the street, as these can result in pools that support larval mosquitoes
    • If making landscape decisions, consider ways to minimize overspray (of irrigation) to streets and gutters
  • Wear long pants, long-sleeved shirts, and socks in areas where mosquitoes are active
  • Use an insect repellent containing DEET, picaridin, oil of lemon eucalyptus, or para-menthane-diol. The EPA has a database where you can search for and find a repellent that is right for you.

In addition to eliminating sources of standing water around your home weekly, you can also mosquito-proof your home by installing or repairing screens on windows and doors.

West Nile virus detected in four Colorado counties, as experts brace for active mosquito season

How to spot a West Nile virus infection

Symptoms of West Nile virus infection appear two to 14 days after exposure, with 1 in 5 people developing fever, body aches, headache, vomiting, diarrhea, joint pain, weakness and occasionally skin rashes and swollen nymph nodes.

While most people infected with West Nile virus don’t have symptoms, around 1% of those infected can develop a serious, sometimes fatal, neuroinvasive disease that 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, according to the DDPHE.

People older than 60 years old or those with certain medical conditions such as being immunocompromised, diabetic, fighting cancer or those with kidney disease are most at risk of developing neuroinvasive disease, according to Dr. Daniel Pastula, an infectious disease specialist at UCHealth and chief of neuro-infectious diseases and global neurology at the University of Colorado School of Medicine and Colorado School of Public Health.

People should talk to their doctors or their health care provider if they experience any of these symptoms, especially if you develop a fever with severe headaches or confusion following a mosquito bite.

While there is no treatment, cure, or vaccine to protect against West Nile virus, medical professionals can treat symptoms to help patients feel better and possibly recover more quickly, Denver health officials said.

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.

Last year, Colorado reported 206 human cases of West Nile virus, including 20 deaths.

D7 follow up bar 2460x400FINAL.png
The Follow Up
What do you want Denver7 to follow up on? Is there a story, topic or issue you want us to revisit? Let us know with the contact form below.