Recent Visitor Grand Canyon North Rim Treated for Tick-Borne Relapsing Fever

Grand Canyon, Ariz.–Grand Canyon National Park, the National Park Service Office of Public Health, Coconino County Public Health Services District, and other park partners are investigating a positive case of tick-borne relapsing fever (TBRF) contracted by a recent visitor to the North Rim. Prior to becoming ill, the visitor had been vacationing on the North Rim of Grand Canyon National Park and adjacent areas in mid-September. The visitor was treated successfully with a course of antibiotics.

TBRF is a rare, but treatable and curable, bacterial infection that occurs in the western United States. People contract TBRF after being bitten by infected soft ticks, which typically feed on rodents. Bites from soft ticks are painless, brief (15 to 20 minutes), and usually happen at night when humans are asleep. Most infections are associated with sleeping in cabins in mountainous areas where rodents are present.

Common symptoms of TBRF include high fever (103-104°F; 39-40°C), headache, chills, and muscle aches. Nausea, vomiting, abdominal pain, and rash may also occur. TBRF is characterized by recurring ("relapsing" episodes of symptoms that usually last about three days, disappear for seven days, then return. Most people who are infected with TBRF develop symptoms approximately seven days after being bitten by the tick. TBRF is not transmitted from person to person.

There are usually less than 50 reported cases of TBRF in the United States annually. Though uncommon, two outbreaks have occurred on the North Rim of Grand Canyon in the last 42 years. In 1973, 62 cases were reported. In 1990, 17 cases were reported.

Individuals with travel history to the North Rim and symptoms consistent with TBRF should consult a healthcare provider and discuss potential exposures. TBRF is treatable with a commonly available antibiotic (doxycycline).