But that doesn't mean the virus isn't present in other parts of the state, said JoDee Baker, an epidemiologist at the Utah Department of Health.
"There is no vaccine for humans. So, taking simple precautions to avoid mosquito bites is the key to reducing your risk for infection," she said. "We usually see more increased activity in August, and the south has seen a lot of rain, generating a lot of activity."
Mosquito pools in Uintah and Box Elder counties have also tested positive for the virus, Baker said, noting West Nile season doesn't end until the first hard freeze.
It's not unusual for Utah to have two to three confirmed human cases of West Nile a year, Baker said.
Most people infected by the virus won't notice any symptoms, but some will experience symptoms meriting a visit to the doctor: high fever, severe headache and stiff neck, disorientation and confusion. The elderly and people with poor immune systems are at higher risk for symptoms that lead to hospitalization, disability and death.
Not all mosquitoes carry the virus. Those that do are typically out from dusk to dawn. The U.S. Centers for Disease Control and Prevention (CDC) recommend that people outdoors during those times wear protective clothing and mosquito repellent containing DEET.
West Nile surveillance will continue into the fall. For updated reports visit www.health.utah.gov/wnv.
You can report bodies of stagnant water to your local Mosquito Abatement District. A list of districts can be found at: http://www.umaa.org/.
Preventing West Nile
Use mosquito repellents containing DEET, picaridin, or oil of lemon eucalyptus when outdoors. The American Academy of Pediatrics recommends that repellents should contain no more than 30 percent DEET when used on children. Insect repellents also are not recommended for children younger than two months of age.
Wear long-sleeved shirts and pants while outdoors.
Remove any puddles or standing water around your home where mosquitoes can breed, including birdbaths, small swimming pools, old tires, buckets and plant containers.
Contact a veterinarian for information on vaccinating horses.