Borelliosis (Relapsing Fever)

Abstract

Relapsing fever (louseborne [epidemic] relapsing fever, tickborne [endemic] relapsing fever) is an acute febrile, septicemic illness of humans caused by spirochetes of the genus Borrelia. Borrelia recurrentis is the etiologic agent of louseborne relapsing fever and is transmitted by the body louse. The vectors of tickborne relapsing fever are the soft ticks, and a number of Borrelia species can be transmitted by these arthropods. The relapsing fevers are widely distributed in both tropical and temperate climates. Large epidemics of louseborne relapsing fever have occurred throughout Europe, Africa, Asia, and South America, and cases continue to be reported from African countries. Little is known about the worldwide incidence of tickborne relapsing fevers because of their sporadic occurrence.