RESUMEN
During August 2014, five high school students who had attended an outdoor education camp were hospitalized with a febrile illness, prompting further investigation. Ten total cases of tick-borne relapsing fever (TBRF) were identified-six cases confirmed by culture or visualization of spirochetes on blood smear and four probable cases with compatible symptoms (attack rate: 23%). All patients had slept in the campsite's only cabin. Before the camp, a professional pest control company had rodent proofed the cabin, but no acaricides had been applied. Cabin inspection after the camp found rodents and Ornithodoros ticks, the vector of TBRF. Blood samples from a chipmunk trapped near the cabin and from patients contained Borrelia hermsii with identical gene sequences (100% over 630 base pairs). Health departments in TBRF endemic areas should consider educating cabin owners and pest control companies to apply acaricides during or following rodent proofing, because ticks that lack rodents for a blood meal might feed on humans.
Asunto(s)
Brotes de Enfermedades , Fiebre Recurrente/epidemiología , Adolescente , Adulto , Animales , Arizona/epidemiología , Borrelia/genética , Acampada , Fútbol Americano , Humanos , Masculino , Ornithodoros/microbiología , Filogenia , Fiebre Recurrente/etiología , Fiebre Recurrente/microbiología , Roedores/parasitologíaRESUMEN
Tickborne relapsing fever (TBRF) is a bacterial infection characterized by recurring episodes of fever, headache, muscle and joint aches, and nausea. In North America, TBRF primarily is caused by Borrelia hermsii spirochetes transmitted by Ornithodoros hermsii ticks. Once infected, these soft ticks are infectious for life and transmit the spirochete to sleeping humans quickly (possibly within 30 seconds) during short feeds (15-90 minutes). On August 10, 2014, the Coconino County Public Health Services District in Arizona was notified by a local hospital that five high school students who attended the same outdoor education camp had been hospitalized with fever, headache, and myalgias. Hantavirus infection initially was suspected because of reported exposure to rodent droppings, but after detecting spirochetes on peripheral blood smears from all five hospitalized students, TBRF was diagnosed. The camp was instructed to close immediately, and the health department, in collaboration with local university experts, investigated to identify additional cases, determine the cause, and prevent further infections. A total of 11 cases (six confirmed and five probable) were identified.