May 5, 2018

Lyme-carrying ticks and other dangerous pests are creeping into Utah, thanks to climate change

Utah
USA
by
Emma Penrod
,
The Salt Lake Tribune
Big Elk Lake, as seen on July 13, 2015, sits at the end of a 1.75 mile trail in the Uinta Mountains in Summit County. Summit County is one of five counties in Utah that has had a report of Lyme disease. Photo: Nate Carlisle, Salt Lake Tribune
Big Elk Lake, as seen on July 13, 2015, sits at the end of a 1.75 mile trail in the Uinta Mountains in Summit County. Summit County is one of five counties in Utah that has had a report of Lyme disease. Photo: Nate Carlisle, Salt Lake Tribune

Utah has traditionally been safe from Lyme and many other insect-borne diseases, thanks to its long, cold winters — but appears to be changing.

According to data from the Centers for Disease Control and Prevention, reports of Lyme disease in Utah have been trending upward over the past decade and a half. Confirmed cases jumped more than 500 percent, from just three in 2000 to 19 in 2016.

Most Utahns who contract Lyme disease still get the infection while traveling the East Coast, said Dallin Peterson, an epidemiologist and specialist in insect- and animal-borne diseases for the Utah Department of Health. But, he said, one of the tick species known to carry the bacteria that causes Lyme, the Western black-legged tick, has migrated to Utah.

Traditionally, that species has mostly inhabited Washington, Oregon and California, Peterson said, but recently it appears to be moving east into Idaho and Utah.

Climate change is likely helping to spread disease-carrying insects into the state, which has been relatively free of insect-borne diseases. The ticks that carry Lyme disease have a two-year life cycle, according to Sam LeFevre, manager of the Utah Department of Health’s Environmental Epidemiology Program.

In temperate states, cold winter weather should kill large numbers of young ticks each year. But as average temperatures climb, LeFevre said, more ticks are surviving each winter to breed the following spring.

“Thus,” he said, “we have a population explosion.”