So far this year, 114 mosquito pools in Utah have tested positive for West Nile, according to the Utah Department of Health. A mosquito pool is a group of mosquitoes caught and tested from a single trap – it is not related to swimming pools or pools of water.
In early July, a West Nile-positive mosquito pool was confirmed in Bear Lake County near the Idaho-Utah border. A week later, Davis County officials confirmed two mosquito pools tested positive for West Nile.
While no human cases of West Nile have been reported this year, UDOH reports mosquitoes are very active and is still important to take precautions to avoid mosquito bites.
“West Nile virus is a yearly presence in Utah and it isn’t going away,” says Hannah Rettler, 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.”
To reduce your risk of infection, UDOH recommends:
- 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). See a list of MADs here.
- 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 after being bit by an infected mosquito. Health officials report a majority of people infected by West Nile will not notice any symptoms. Still, some may experience flu-like symptoms or worse.
According to UDOH, the elderly and people with poor immune systems are at a higher risk for symptomatic disease. Most serious cases of West Nile can lead to hospitalization, disability, or death.
People with severe forms of West Nile virus may experience symptoms of high fever, severe headache, stiff neck, disorientation, and confusion.
If you are experiencing these symptoms, you are encouraged to contact your healthcare provider immediately.
West Nile virus surveillance continues until early fall. For more information, click here.