Cases of Soft Tick Relapsing Fever Continue to Occur in the Western U.S.

Soft tick relapsing fever (STRF) is a rare infection transmitted to humans by soft-bodied ticks; it can cause a recurring high fever accompanied by headache, nausea, and muscle or joint pain. Early antibiotic treatment is critical to prevent complications. A new MMWR, released by the CDC shows that from 2012 to 2021, 251 cases of STRF, also known as tickborne relapsing fever, were identified in 11 of 12 states where the infection is reportable. More than half of the patients were hospitalized; no deaths occurred. People should avoid sleeping in rodent-infested structures such as rustic mountain cabins and caves where STRF is common in the western U.S.