Lecture 51 - 3rd Asessment - Trypanosomes

TRYPANOSOMES AFRICAN TRYPANSOMIASIS : Trypanosoma brucei rhodesiense (T.b.r.), T.b. gambiense (T.b.g.) GEOGRAPHIC DISTRIBUTION: Rhodesian (T.b.r.) East Africa; Gambian (T.b.g.) West Africa. IMPORTANCE: 10,000-20,000 new cases; 1% -5% deaths. MORPHOLOGY: Trypomastigotes in blood / CSF. LIFE CYCLE: Bite of Glossina sp., Chancre, Multiplication at site of bite, blood, CSF. PATHOLOGY: Site of bite,

Perivascular infiltration of endothelial,

lymphoid and plasma cells. CLINICAL SYMPTOMS: Inflammatory nodule, Fever, headache, joint pains, lymph node

Trypanosomiasis

enlargement, CNS impairment, lethargy. Death. T.b.r. (Acute) patient may die in 9 months. T.b.g. (chronic) patient may die in 2 years. Death from malnutrition / intercurrent infection. EPIDEMIOLOGY: Grassland and Riverine tsetse (Glossina sp.).

Reservoir hosts.

LABORATORY DIAGNOSIS: Blood /Lymph gland juice/ CSF, Concentration methods. Check for trypomastigote in CSF.

Animal innoculation (?)

TREATMENT: Blood phase (Suramin);

CNS involvement - Mel B.

AMERICAN TRYPANOSOMIASIS: Trypanosoma cruzi GEOGRAPHIC DISTRIBUTION:

IMPORTANCE: 16 to 18 million infected.

MORPHOLOGY: C-shaped trypomastigote.

Amastigote.

Trypanosomiasis

LIFE CYCLE: Triatomid bugs feed, suck up trypomastigotes, multiply as epimastigotes, faecal contamination-trypomastigotes. In man, macrophages ingest trypomastigotes, amastigotes,

mutiply,

burst,

spread to organs.

PATHOLOGY: Parasites (amastigotes) in cardiac, sketetal muscle fibers. of inflammation,

Patchy areas

Fibrosis and hypertrophy of organs. CLINICAL SYMPTOMS AND SIGNS : Fever, Oedema of eye and face, Enlarged spleen, liver and lymph nodes. Acute destruction of cardiac muscle.

Megacolon,

Megaesophagus. LAB DIAGNOSIS: Blood (trypomastigote). Culture. Xenodiagnosis. SerologyInterpretation TREATMENT: Benznidazole, nifurtimox; Mega disease:surgery. PREVENTION: Upgrade accommodation.

EPIDEMIOLOGY: Congenital infection

Transfusion ?

ENTOMOLOGY OF TRYPANOSOMIASIS Glossina sp.

(ORDER: DIPTERA; FAMILY: MUSCIDAE)

DISTRIBUTION: Southern Arabia, East and West Africa. MORPHOLOGY: Yellow, brown black. 10mm. wings.

Resting position of

Proboscis. Arista with bristles. Wing with hatchet cell. HABITS: Savannah: G. morsitans; Riverine: G. palpalis. Male and Female are daybiters. Mouth parts-piercing type-enter wound.

Vision, body heat, smell attract.

Flight range short. LIFE CYCLE: Egg in uterus, produce larva, burrows, pupa, adult (5 weeks). PATHOGENICITY: Bite (sensitive to saliva); Trypanosomes.

CONTROL: Clear trees, Barriers. Insecticides. Trap flies. Destroy game (?) Triatoma sp. Rhodnius sp. (ORDER: HEMIPTERA; FAMILY: REDUVIIDAE) DISTRIBUTION: MORPHOLOGY: Long narrow heads (cone-nosed), dark brown. LIFE CYCLE: Barrel-shaped eggs, development incomplete, young bug feeds, molt, becomes adult-fly for short distances. HABITS: Hide in crevices, avoid light, bite at night. Trypanosomes multiply in mid and hind gut, infective stage, bug defaecates, contamination of wound and mucous membranes.

PATHOGENICITY: Both sexes suck blood, sensitized-prominent local reaction, scratch, method of entry of trypanosomes TREATMENT: Calamine lotion, topical steroids (?) CONTROL: Insecticides, inside houses, upgrade housing, juvenile hormones to control moulting.

Trypanosomiasis

Trypanosomiasis