Trypanosomiasis

Question 1

List the 2 species responsible for African trypanosomiasis in human and their vector

Answer 1

• Trypanosoma brucei rhodesiense
• Trypanosoma brucei gambiense

*Vector: transmitted by the tsetse flies

Question 2

Differentiate the epidemiology ,disease progression ,acute/ chronic , reserivor hosts

Answer 2

> Epidemiology
*TBR: East African trypanosomiasis and the vectors are tsetse flies of the Glossina morsitans group which prefer a savannah environment

*TBG: West African trypanosomiasis (Central and West Africa) and Vectors are tsetse flies of Glossina palpalis group which prefer a river, forest environment

> Disease progression :

• TBR : an acute ,serious rapid disease
• TBG : Long term outcome and fatal if not treated

> Host reservoir :
*TBR: game animals eg antelopes, lion and hyenas ,
and domestic animals eg cattle
*TBG: Humans, domestic animals, and wild animals

Question 3

Discuss the lifecycle of the Trypanosoma?

Answer 3

The parasite enters the bloodstream as pleomorphic trypomastigotes (which are either short and broad/long and slender ) > Tsetse (male &female ) bites ingest trypomastigotes which migrate into the salivary glad where further multiplication produces epimastigotes

Question 4

Discuss the pathology and clinical presentation of Trypanosoma

Answer 4

*Infected (particularly TB rhodesiense ) tsetse produce a nodular reaction called trypanosomal chancre which disappears after few weeks
*Trypomastigotes appear in the bloodstream 1-2 weeks after a bite
* pyrexia, night sweats, persistent headaches occur during parasitemia
*Maculopapular rash mainly on the trunk
*Moderate hepatosplenectomy
*lymphadenopathy
*Winterbottom’s sign: marked posterior cervical triangle
*Gland aspirate shows the presence of trypanosomes
*Kerandels sign: Hyperesthesia
*Weakness, muscle cramp, and pancarditis
*EASTERN AFRICAN FORM MANY DIE FROM MYOCARDITIS BEFORE INVOLVEMENT OF THE CNS AND IT IS RESPONSIBLE FOR THE SLEEPING SICKNESS
*Coma, convulsion, and death
facial edema

Question 5

Diagnosis of trypanosomiasis

Answer 5

• Microscopic examination of Giesma stained blood
• aspirate the chancre
• lymphnode examination
• > protein level (>40mg/100 ml)
• Serology tests

Question 6

Treatment of Trypanosoma

Answer 6

• Suramin in early stages
• Melarsoprol used in CNS involvement (SE: Exfoliative dermatitis )
• Difluoromethylornithine (DFMO) less toxic and more effective against early stages and CNS involvement and it is taken in combination with Suramin

Question 7

Prevention and control of Trypanosoma

Answer 7

• No vaccines therefore awareness is the best

* Insecticides and tsetse traps