African Trypanosomiasis - Sleeping Sickness

               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

Advanced Symptoms :

• 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.