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West Nile virus cases are soaring in Larimer County even before peak season begins, health officials say

The county has reported 25 human cases of West Nile Virus as of Aug. 17, the most in any county across the state
More cases of West Nile virus reported in Colorado
Posted at 7:40 AM, Aug 18, 2023
and last updated 2023-08-18 09:40:29-04

LARIMER COUNTY, Colo. — The number of confirmed human cases of West Nile virus has soared to 25 in Larimer County, concerning health officials who said Thursday peak season is still a few weeks away.

By comparison, there were only 15 human cases of West Nile virus in all of 2022, according to a spokesperson with the Larimer County Department of Health and Environment (LCDHE), who said in a news release Thursday that on average, the county sees around 23 cases per year.

Cases there have jumped from eight people on Aug. 8 to the current 25 — the most of any county so far. Of those, at least 7 people have required hospitalization due to complications from the disease.

Health officials warned the significant increase in cases is expected to continue.

“Larimer County typically does not see a peak in human West Nile cases until late August, early September. Unfortunately, we will likely continue to see cases and hospitalizations rise,” said Larimer County Public Health Director Tom Gonzales.

Most of the seven hospitalized cases were admitted after showing symptoms of neuroinvasive disease, health officials said.

The latest reports of West Nile virus in humans in Larimer County adds to the concerns experts have expressed since the beginning of July because of an increase in Culex mosquitoes in Colorado spawned by a wet and cool spring and early summer rainfall.

Colorado reported its first death attributed to West Nile virus in early August, after a 53-year-old man in Weld County died from complications of the disease.

The latest data from the Colorado Department of Public Health and Environment (CDPHE) showed at least 19 people across the state had to hospitalized due to neuroinvasive disease.

The following Colorado counties have reported human cases of West Nile Virus as of the same time period.

  • Adams: 2
  • Arapahoe: 3
  • Boulder: 2
  • Delta: 1
  • Denver: 3
  • El Paso: 2
  • Fremont: 1
  • Jefferson: 1
  • La Plata: 1
  • Larimer: 8
  • Mesa: 1
  • Morgan: 2
  • Pueblo: 2
  • Weld: 7

The symptoms of a West Nile virus infection can vary greatly, with the majority of infected people showing no symptoms at all. Generally, it takes two to 14 days after infection for symptoms to appear, which can include nausea, vomiting, fever, weakness in muscles, rashes and headaches, according to the CDPHE.

While the majority of infected people don’t show symptoms, those that do typically experience headaches, weakness, fatigue, gastrointestinal symptoms and skin rashes. Around 1% of those infected can develop a serious, sometimes fatal, neuroinvasive disease, such as meningitis and encephalitis, the CDPHE said.

There are no medications to treat, or vaccines to prevent, a West Nile virus infection.

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.