Makindo Medical Notes

🐭 Rodents are the main reservoir globally, except in East Africa where humans themselves act as the reservoir. 🦟 Transmitted by soft ticks (Ornithodoros spp.), which feed quickly and often unnoticed at night.

🧾 About

• Caused by Borrelia duttonii and related spirochetes.
• Endemic in parts of Africa, Asia, and the Americas.
• Transmission occurs when infected ticks feed → spirochetes in saliva enter bloodstream.
• Unlike louse-borne relapsing fever, multiple relapses are common due to Borrelia’s antigenic variation.

🩺 Clinical Features

• Incubation: 5–15 days.
• Fever: recurrent high fevers lasting 3–10 days, separated by afebrile periods of 5–7 days.
• Headache, meningitis-like symptoms, rigors, myalgia, arthralgia.
• Hepatosplenomegaly and jaundice may develop.
• Thrombocytopenia → petechiae, epistaxis, serosal haemorrhage.
• Relapses may occur 3–10 times if untreated.
• Severe cases: myocarditis, pneumonia, neurological involvement (meningoencephalitis).

🔬 Investigations

• Microscopy: Spirochetes seen on peripheral blood smear (best during febrile episode) or dark-field microscopy.
• FBC: Anaemia, thrombocytopenia, leukopenia.
• Serology/PCR: can confirm diagnosis where available.

💊 Management

• Adults: Tetracycline 500 mg PO QID for 7–10 days.
• Children & Pregnancy: Erythromycin 500 mg PO QID for 7–10 days.
• Alternative: Doxycycline 100 mg PO BD for 7–10 days.
• Jarisch–Herxheimer reaction ⚠️: common after first dose → fever, rigors, hypotension → supportive management (fluids, antipyretics, monitoring).
• Supportive care: fluids, analgesia, monitoring for complications.

📊 Comparison: Louse-Borne vs Tick-Borne Relapsing Fever

🛡️ Prevention

• Vector control: avoid tick-infested areas, improve housing conditions.
• Bed nets, insect repellents, and avoidance of rodent habitats.
• Public health measures important in endemic regions.

📚 References

• CDC – Relapsing Fever
• WHO – Relapsing Fever