''Borrelia recurrentis'' is a species of ''

Borrelia ''Borrelia'' is a genus of bacteria of the spirochete phylum. Several species cause Lyme disease, also called Lyme borreliosis, a zoonotic, vector-borne disease transmitted by ticks. Other species of ''Borrelia'' cause relapsing fever, and are tr ...

'', a

spirochaete A spirochaete () or spirochete is a member of the phylum Spirochaetota (), (synonym Spirochaetes) which contains distinctive diderm (double-membrane) gram-negative bacteria, most of which have long, helically coiled (corkscrew-shaped or s ...

bacterium Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...

associated with

relapsing fever Relapsing fever is a vector-borne disease caused by infection with certain bacteria in the genus ''Borrelia'', which is transmitted through the bites of lice or soft-bodied ticks (genus ''Ornithodoros''). Signs and symptoms Most people who are ...

. ''B. recurrentis'' is usually transmitted from person to person by the

human body louse The body louse (''Pediculus humanus humanus'', also known as ''Pediculus humanus corporis'') is a hematophagic ectoparasite louse that infests humans. It is one of three lice which infest humans, the other two being the head louse, and the c ...

. Since the 1800s, the body louse has been known as its only known vector. ''B. recurrentis'' DNA was found in 23% of head lice from patients with louse-borne relapsing fever in Ethiopia. Whether head lice can transmit these bacteria from one person to another remains to be determined. It is notable for its ability to alter the proteins expressed on its surface, which causes the "relapsing" characteristic of relapsing fever.

References

recurrentis {{spirochaetes-stub