Tick-borne relapsing fever in a premature infant.

Relapsing fever is caused by the Borrelia species of spirochetes. Louse-born epidemics of the disease may occur but the endemic disease is usually transmitted to humans by the bite of an infected tick (Ornithodorus). Transplacental infection was suggested more than 75 years ago (1) but has been rarely documented (2). We describe a case of neonatal relapsing fever where maternal infection was the probable cause of the premature delivery and infection in the infant.