Louse-borne relapsing fever

**Definition:** A spirochaetal infection caused by the human to human transmission of Borrelia recurrentis by the human body louse. Epidemics are associated with poor living conditions as may result from famine or war. Episodic fever may progress to severe jaundice, haemorrhage, confusion and death. Confirmation is by identification of Borrelia in blood films.

**Long definition:** Louse-borne relapsing fever is due to the transmission from human to human of the spirochaete Borrelia recurrentis by the human body louse. Although it occurs sporadically in endemic areas including Ethiopia and Sudan, it may result in large epidemics in situations where overcrowding and poor sanitation exist, as may occur as a result of war. It is characterized by episodes of high fever accompanied by headache, photophobia, myalgia, abdominal pain and severe systemic upset with jaundice, haemoptysis, hypotension and petechial rash. If it is untreated the mortality rate may reach 70%.

**Inclusions:** - Relapsing fever due to Borrelia recurrentis