West Nile Virus Detected in Utah Mosquitoes

Joe DoughertyFeatured News

(Salt Lake City, UT) – A total of 114 positive mosquito pools for West Nile virus have been reported throughout Utah this year, according to the Utah Department of Health (UDOH). “Mosquito pool” is the term used for a group of mosquitoes caught and tested from a single trap; it is not related to swimming pools or pools of water. Even though no human cases have been reported this year, mosquitoes are very active and it’s always a good idea to take simple precautions to avoid mosquito bites.

“West Nile virus is a yearly presence in Utah and it isn’t going away,” said Hannah Rettler, Utah Department of Health (UDOH) Vectorborne/Zoonotic Epidemiologist. “Even though the number of human cases has decreased in recent years, it is important to understand that West Nile virus has established itself in mosquito populations in the state. Since 2009, Utah records an average of 12 human cases of West Nile virus each year, ranging between two and 21 cases. In 2019, there were 21 human cases, and in 2020 there were two. Some of those cases can be quite severe or even result in death.”

Taking these simple precautions to avoid mosquito bites is the best way to reduce your risk for infection.

  • Wear long-sleeves, long pants, and socks while outdoors and use an insect repellent with 20%-30% DEET, which is safe to use during pregnancy. Repellents are not recommended for children younger than two months of age.
  • The hours from dusk to dawn are peak biting times for many mosquitoes. Consider rescheduling outdoor activities that occur during evening or early morning.
  • Mosquitoes lay their eggs in standing water. Remove any puddles of water or standing water including in pet dishes, flower pots, wading and swimming pools, buckets, tarps, and tires.
  • Report bodies of stagnant water to your local Mosquito Abatement District (MAD). Visit http://www.umaa.org/ for a list of MADs.
  • Keep doors, windows, and screens in good condition and make sure they fit tightly.
  • Consult with an immunization travel clinic before traveling to areas that may have mosquito-borne illness such as Zika or dengue and take the necessary precautions.

West Nile virus is usually transmitted to humans through the bite of an infected mosquito, and not all mosquitoes carry the virus. A majority of people infected by this virus (70–80%) won’t notice any symptoms while some people may experience flu-like symptoms or worse. The elderly and people with poor immune systems are at higher risk for symptomatic disease. The most serious cases can lead to hospitalization, disability, or death. Symptoms of the severe form of West Nile virus include high fever, severe headache and stiff neck, disorientation, and confusion. If you are experiencing symptoms, contact your healthcare provider immediately.

West Nile virus surveillance in Utah is underway and will continue into early fall. For more information, call your local health department or visit https://epi.health.utah.gov/west-nile-virus/.

Rebecca Ward

(w): 801-538-6682

(c): 801-352-1270