African Trypanosomiasis :
African Trypanosomiasis, also known as sleeping sickness, is a parasites of the genus Trypanosoma. It primarily affects humans and animals in sub-Saharan Africa.
Causative Agent :
The disease is caused by two subspecies of Trypanosoma brucei :
- Trypanosoma brucei gambiense - causes the chronic form of the disease, prevalent in West and Central Africa.
- Trypanosoma brucei rhodesiense - causes the acute form, found in East and Southern Africa.
Transmission :
- Transmitted through the bite of an infected tsetse fly (Glossina species), which acts as the vector.
- The fly becomes infected by biting a host already carrying the parasite.
Pathophysiology :
Stage 1 : Hemolymphatic Phase
- The parasite multiplies in the blood and lymphatic system.
- Symptoms include fever, headaches, joint pain, and swollen lymph nodes (especially in the neck, known as winterbottom's sign).
Stage2 : Neurological Phase
- The parasite crosses the blood-brain barrier, affecting the central nervous system (CNS).
- Symptoms include confusion, behavioral changes, sleep disturbances (reversal of sleep patterns), and ultimately coma if untreated.
Symptoms :
Early Symptoms :
- Fever
- Severe headaches
- Muscle aches
- Fatigue
- Enlarged lymph nodes
- Disruption of sleep-wake cycles (hence "sleeping sickness")
- Neurological and psychiatric disorders
- Seizures and eventual coma
Diagnosis :
- Microscopy : Identification of parasites in blood, lymph node aspirates, or cerebrospinal fluid (CSF).
- Serological Tests : Detect antibodies, especially for T. b. gambiense.
- Lumbar Puncture : To assess CNS involvement by examining CSF.
Treatment :
Stage 1 :
- Pentamidine for T. b. gambiense.
- Suramin for T. b. rhodesiense.
Stage 2 (CNS involvement) :
- Melarsoprol (effective but highly toxic).
- Eflorithine (Safer alternative, especially for T. b. gambiense).
- Combination therapy with nifurtimox and eflornithine (NECT) is now widely used.
Prevention :
- Control of tsetse flies through insecticides and traps.
- Wearing protective clothing to reduce exposure.
- Surveillance programs to identify and treat cases early.
Epidemiology :
- T. b. gambiense accounts for about 98 percents of reported cases.
- WHO efforts have significantly reduced cases, with the goal of eliminating sleeping sickness as a public health problem by 2030.
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