Tickborne relapsing fever, Bitterroot Valley, Montana, USA.

In July 2013, a resident of the Bitterroot Valley in western Montana, USA, contracted tickborne relapsing fever caused by an infection with the spirochete Borrelia hermsii. The patient's travel history and activities before onset of illness indicated a possible exposure on his residential property on the eastern side of the valley. An onsite investigation of the potential exposure site found the vector, Ornithodoros hermsi ticks, and 1 chipmunk infected with spirochetes, which on the basis of multilocus sequence typing were identical to the spirochete isolated from the patient.

Detection of Borrelia theileri in Rhipicephalus geigyi from Mali.

Disease burden within cattle is a concern around the world. Bovine borreliosis, one such disease, is caused by the spirochete Borrelia theileri transmitted by the bite of an infected Rhipicephalus (Boophilus) species tick. A number of species within the genus are capable of transmitting the agent and are found on multiple continents.

Endemic foci of the tick-borne relapsing fever spirochete Borrelia crocidurae in Mali, West Africa, and the potential for human infection.

Background: Tick-borne relapsing fever spirochetes are maintained in endemic foci that involve a diversity of small mammals and argasid ticks in the genus Ornithodoros. Most epidemiological studies of tick-borne relapsing fever in West Africa caused by Borrelia crocidurae have been conducted in Senegal. The risk for humans to acquire relapsing fever in Mali is uncertain, as only a few human cases have been identified.

Acquisition and subsequent transmission of Borrelia hermsii by the soft tick Ornithodoros hermsi.

Tick-borne relapsing fever is caused by spirochetes within the genus Borrelia. The hallmark of this disease is recurrent febrile episodes and high spirochete densities in mammalian blood resulting from immune evasion. Between episodes of spirochetemia when bacterial densities are low, it is unknown whether ticks can acquire the spirochetes, become colonized by the bacteria, and subsequently transmit the bacteria once they feed again.

Bloodmeal size and spirochete acquisition of Ornithodoros hermsi (Acari: Argasidae) during feeding.

Ornithodoros hermsi Wheeler (Acari: Argasidae) is the vector of Borrelia hermsii, the primary cause of tick-borne relapsing fever in North America. This tick is one of the smallest Ornithodoros species involved with the biological transmission of spirochetes; yet, the amount of blood ingested while feeding is unknown. Therefore, we determined the amount of blood O.

A novel surface antigen of relapsing fever spirochetes can discriminate between relapsing fever and Lyme borreliosis.

In a previous immunoproteome analysis of Borrelia hermsii, candidate antigens that bound IgM antibodies from mice and patients infected with relapsing fever spirochetes were identified. One candidate that was identified is a hypothetical protein with a molecular mass of 57 kDa that we have designated Borrelia immunogenic protein A (BipA). This protein was further investigated as a potential diagnostic antigen for B.