Skip to main content

Three hospitalized Mesa County residents have tested positive for West Nile Virus during the month of August. All three cases were over 70 years old.

“Last year we had one hospitalization in September,” said Rachel Burmeister, Disease Surveillance and Emergency Response Program Manager for Mesa County Public Health. “We had a very wet winter and are seeing the results now with increased mosquito activity and higher cases of West Nile virus.”

Mosquitos continue to test positive for the virus throughout the valley. The public can view a mosquito heat map and look at specific mosquito traps on the Grand River Mosquito Control District website,

Local and State Situation

In Colorado, there have been 193 cases of West Nile Virus so far in 2023. Approximately 106 people have required hospitalization. There have been 13 deaths.

In Mesa County, 7 people have tested positive for West Nile Virus and we anticipate more cases in September.


Prevention is important because there is no specific treatment for West Nile virus.

Follow these steps to limit risk for mosquito bites: 

  • Use an EPA-approved insect repellent effective against mosquitoes. Look for one that contains DEET, Picaridin, IR3535, 2-undecanone, or oil of lemon eucalyptus.
  • Dress in long sleeves and pants when in areas where mosquitoes are active.
  • Avoid being outdoors at dusk and dawn; this is when mosquitoes are most active.
  • Drain and remove sources of standing water on your property.

Talk with a health care provider if you develop a fever with severe headaches or confusion. 


  • The West Nile virus season runs from May through October with case counts typically peaking in September. 
  • Most people who are infected with West Nile virus do not get sick. In fact, about 75-80% of cases are asymptomatic. For those who do experience symptoms, they can range from mild illness to severe encephalitis, which is inflammation of the brain. 
  • People who are over the age of 50 are at the highest risk for severe illness. 
  • This is not a condition that spreads from person-to-person.
Description of West Nile virus and prevention activities.
Public Health Agency

Media Inquiries, contact:

Allison Howe
Public Health Agency
Mesa County Health Department Public Information Officer
Adult spraying insect repellent on another person's arm.