Relapsing Fever

Relapsing fever is a spirochaetal illness caused by Borrelia species, with recurrent febrile episodes.

• Louse borne (epidemic): Borrelia recurrentis, spread by body lice, in conditions of overcrowding, war, and displacement (Ethiopia, Sudan, Somalia, and refugee populations in Europe).
• Tick borne (endemic): Borrelia duttonii (East and Central Africa, including Kenya and Tanzania), B. hermsii, B. turicatae, B. crocidurae (West Africa), B. persica, and others, spread by Ornithodoros soft ticks.
• Louse borne mortality is 10 to 40% untreated; tick borne 2 to 5%.
• Pregnancy: high risk of miscarriage, stillbirth, and neonatal infection.

• Abrupt high fever, rigors, headache, myalgia, arthralgia, nausea, and vomiting; lasts 3 to 7 days, then afebrile for 4 to 14 days before relapse.
• Hepatosplenomegaly, jaundice, petechiae, epistaxis, and bleeding in louse borne disease.
• Neurological involvement: meningitis, cranial nerve palsies (especially facial palsy in B. duttonii), and encephalitis.
• Complications: myocarditis, ARDS, liver failure, and iritis.

• Thick and thin blood films stained with Giemsa during febrile episodes (spirochaetes seen in the blood), or dark field microscopy.
• PCR or serology (cross reaction with Lyme, GlpQ antigen).
• Blood: thrombocytopenia, anaemia, raised bilirubin, and transaminases.
• Exclude malaria (co-infection common), typhoid, typhus, leptospirosis, dengue, viral haemorrhagic fevers, and brucellosis.

• Louse borne: single dose of doxycycline 100 mg (200 mg in adults), or erythromycin 500 mg, or procaine penicillin G 600,000 units IM (or benzathine penicillin G 2.4 MU IM as a single dose alternative).
• Tick borne: doxycycline 100 mg twice daily for 7 to 10 days, or erythromycin 500 mg four times daily; ceftriaxone 2 g IV daily for 10 to 14 days for neuroborreliosis; penicillin G 3 to 4 MU IV every 4 hours as an alternative.
• Jarisch-Herxheimer reaction (in up to 80% of louse borne, 5 to 20% of tick borne): rigors, hyperthermia, then hypotension within 1 to 4 hours of antibiotic; manage with close monitoring, IV fluids, vasopressors, antipyretics; steroids and anti-TNF do not prevent it; treat in a monitored setting.
• Delouse patients and contacts (permethrin 1% or malathion), wash clothing, and improve hygiene and housing.
• Treat malaria empirically in endemic areas and screen pregnant women.