Salt Lake adult hospitalized with severe case of West Nile virus

SALT LAKE CITY — Salt Lake County health officials confirmed the first human case of West Nile virus in the county on Friday. The infected person has been hospitalized with neuroinvasive West Nile virus, a more severe form of the disease.

“There are a growing number of mosquitoes carrying the disease,” said Dr. Angela Dunn, Salt Lake County Health Department executive director, “so it is now especially important that people protect themselves from mosquito bites, particularly in the hours from dusk to dawn.”

Health officials said they could not release any further information about the person due to medical privacy laws. This is the fourth human case of the virus in Utah this year, joining two cases in the TriCounty Health District in eastern Utah and one in the Weber-Morgan Health District.

Testing has detected the virus in mosquitoes across northern Utah, along with Grand, Millard and Washington counties this year. Last year, public health officials confirmed five Utahns contracted the virus, and all recovered.

In 2021, 28 people were confirmed to have West Nile virus and three died. Because only 20–30% of infected people will have any symptoms at all — and many of those will notice only minor, flu-like symptoms — health officials believe it’s likely that infection is more prevalent than the reported case numbers indicate.

Tips to reduce mosquito exposure

• 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 2 months of age.
• The hours from dusk to dawn are peak biting times for many mosquitoes. Consider rescheduling outdoor activities that occur during the evening or early morning.
• Mosquitoes lay their eggs in standing water. Remove any puddles of water or standing water including in pet dishes, flowerpots, 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 illnesses, 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, but not all mosquitoes carry the virus.

Symptoms of West Nile virus infection appear within two to 14 days and include fever, headache and body aches. More severe infections may include high fever, neck stiffness, disorientation, coma, tremors and muscle weakness or convulsions. If you are experiencing symptoms, contact your health care provider immediately.

The Utah Department of Health and Human Services said most people infected with West Nile virus don’t develop any symptoms, but about one in 150 people develop a severe illness that affects the central nervous system. Among patients with the neuroinvasive disease, about one in 10 die.

Mosquito problems this fall

Mosquito abatement crews say they are dealing with more marshland than they’ve seen in decades.

“The Great Salt Lake is so salty… as it comes up into the marsh it kills the vegetation and reduces the mosquito habitat,” said Gary Hatch, director of the Davis County Mosquito Abatement Program.

Low water levels at the Great Salt Lake over the recent years have allowed for the creation of tens of thousands of acres of freshwater marshlands in northern Utah.

“We more than tripled the number of acres that we normally spray in May, just because of the large number of adults we’re seeing,” Hatch told KSL TV in June.

Hatch added the species of mosquito that carries West Nile virus has started to hatch “in big numbers.”

The record-breaking snowpack and additional rain this summer has mosquito experts concerned the state could still see a big jump in mosquito populations as more Utahns stay outside closer to dusk.

“With the extreme high water we have had this spring, this has been a massive mosquito year, as we were expecting, the second highest in the last 15 years,” said Dan Miller, director of the Utah County Health Department Mosquito Abatement District.