For those planning to visit Jordanelle State Park this weekend, know before you go: Some swimmers are getting an irritating but harmless rash there.
At the Jordanelle Reservoir, some have recently reported getting rashes known as “swimmer’s itch.”
Health officials say swimmer’s itch is caused by microscopic larvae called “cercarial.” It causes an allergic reaction on some people’s skin but is otherwise not harmful. The rash can last around a week and is treatable with anti-itch cream..
According to Chris Smoot, who is an epidemiologist with the Wasatch County Health Department, swimmers who get it need not worry for their health. It's just an itchy rash.
“It could cause that rash, but it doesn’t go any further, so a person doesn’t actually become infected. It’s just a reaction to those little larvae trying to complete their life cycle,” Smoot said.
The larvae rely on snails as part of their life cycle. Because snails tend to prefer shallow water, that’s where swimmers are most likely to be exposed.
“They can survive in water. They typically are going to hang out in the shallower areas, so in marshy areas or just kind of the shallow areas where these snails are gonna live, because that snail is the intermediate host, so you need to have these aquatic snails in order to have these larvae hatch and then go into the water,” he added.
The swimmer’s itch reports came from people who swam in shallow water west of the personal watercraft ramp near the Park City Sailing Association. Officials say people can avoid it by swimming out farther in deeper water.
Devan Chavez of the Utah Department of Natural Resources said this is the first time he’s seen this occur in the Jordanelle, and it’s likely a symptom of the reservoir’s low level. It’s currently about 67% full.
“A decrease in overall lake size of water has a couple of different things, like swimmer’s itch," Chavez said. "Because of the heat and because of less water, in cases of swimmer’s itch, it’s often attached to waterfowl and birds and things like that. So, when there’s less floatable water, there’s more increase of people coming into contact with things like that.”
The DNR warns that Utah reservoirs are alarmingly low and draining quickly this summer. Rain scarcity and a weak snowpack last winter have been the main contributing causes to low water levels.
Other reservoirs where people are getting swimmer’s itch include Sand Hollow, Palisade Lake and the new pond at Willard Bay.
