African sleeping sickness ,trypanosomiasis .pptx

Sleeping sickness
Trypanosoma
Treatment
Types
Classes

1. African Sleeping Sickness

2. Introduction : Trypanosoma brucei was Named after Sir Bruce In 1990 Proved that this is transmitted by tsetse fly The three subspecies are; T. brucei gambience T . brucei rhodesiense T . brucei brucei

3. Causative agent African sleeping sickness is caused by Trypanosoma brucei complex. Vector This disease is transmitted by the vector tsetse fly.

4. Forms of sleeping sickness : Based on geographical distribution, sleeping sickness occurs in two forms West African sleeping sickness East African sleeping sickness

5. West African sleeping sickness Agent : Trypanosoma brucei gambiense Vector : Tsetse flies Primary reservoir : Humans CNS disease : Chronic course(months to years) Lymphadenopathy : Frequent, posterior cervical LN increases and is called as winter bottom sign Virulence : Less as the parasitemia is low East African sleeping sickness Agent Trypanosoma brucei rhodesiense Vector Tsetse flies Primary reservoir Animals(Antelope and cattle) CNS disease Acute course <9 months(before that the death occurs) Lymphadenopathy Minimal(axially and inguinal) Virulence More as the parasitemia is high

6. Th e life cycle of trypanosoma brucei includes the following steps: An infected tsetse fly injects metacyclic trypomastigotes i nto the skin tissue of a mammalian host during a blood meal. The parasites enter the lymphatic system and pass into the bloodstream. Inside the host, they transform into bloodstream trypomastigotes . They are carried to other sites throughout the body, including other body fluids like lymph and spinal fluid. They continue to replicate by binary fission tsetse fly injects metacyclic trypomastigotes into the skin tissue of a mammalian host during a blood meal. They continue to replicate by binary fission

7. The life cycle of trypanosoma brucei :

8. Clinical Manifestations This disease manifests in two stages Stage one ( hemolymphatic stage ) Stage two ( CNS invasion )

9. Stage One disease Self-limited lesion( trypanosomal chancre ) appears after the bite of infected tsetse fly. Months to years later febrile illness develops with enlarged posterior cervical nodes(called as Winterbottom’s sign)

10. Stage two disease It involves invasion of CNS which leads to progressive chronic meningoencephalitis. Patients develop characteristic daytime somnolence(hence called as sleeping sickness) Restlessness and insomnia at night

11. Laboratory diagnosis Peripheral blood smear(thick and thin) examination Detecting characteristic trypomastigote forms of T.brucei elongated 14-33 micro meter long, having a flagellum with an undulating membrane CSF examination This is necessary to confirm the CNS invasion; either by Detection of trypomastigotes in CSF or by WBC count of >20 cells/micro litre of CSF, with parasite detected in blood or lymph node aspirate.

12. Other diagnostic modalities include : Culture(blood) onto NNN medium ( Novy – MacNeal –Nicolle ( NNN)) Antigen and antibody detection in serum and CSF Molecular methods Animal inoculation(mice)

13. Treatment Drug of choice West African sleeping sickness Stage one: Pentamidine Stage two: Eflornithine East African sleeping sickness Stage one: Suramin Stage two: Melarsoprol

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