Pathogenic parasitic disease in humans and animals

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2. Introduction
 Trypanosoma is flagellated pathogenic parasite
 Caues fatal disease in humens and and animals.
 The process of disease causing known as
trypanosomiasis.
 It has digentic life cycle
1. In blood of veterbrates
2. In alimentary canal of invertebrates.
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3. HAT
• Human African trypanosomiasis (HAT), also called
sleeping sickness.
• It is caused by the flagellate protozoan Trypanosoma
brucei
• which exists in 2 morphologically identical subspecies:
1. Trypanosoma brucei rhodesiense (East African
trypanosomiasis)
2. Trypanosoma brucei gambiense (West African or
Gambian African trypanosomiasis).
• Both of these parasites are transmitted to human hosts by
bites of infected tsetse flies
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4. Life cycle
 The trypanosomes multiply over a period of 2-3 weeks
in the fly midgut then the trypanosomes migrate
to the salivary gland, where they develop into
epimastigotes. The metacyclic trypomastigotes infect
humans
 Epimastigote is a stage in the life cycle of certain
trypanosomatids wherein the unicellular organism has
a flagellum along the length of its cell body
 Trypomastigote A stage in unicellular life-cycle,
typically trypanosomes, where the flagellum is
posterior of the nucleus, and connected to the cell
body by a long undulating membrane.
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6. SIGN AND SYMPTOMS
 In humans the tsetse fly bite erupts into a red sore and
within a few weeks the person can : Fever
 Swollen lymph glands
 Aching muscles and joints
 Headaches
 irritability
 Slurred speech
 Seizures and difficulty in walking and talking
These problems can develop over many years and if not
treated
• “Leading over many years to death”
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7.  >10%
1. Anemia (55%)
2. Leukopenia (37%)
3. Thrombocytopenia (14%)
 1-10%
1. Seizures (may be due to the disease) (8%)
2. Dizziness
3. Alopecia
4. Vomiting, diarrhea
5. Eosinophilia
6. Hearing impairment
 <1%
1. Abdominal pain
2. Anorexia
3. Facial edema
4. Headache
5. Weakness
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8. IN ANIMALS SIGNS
 Cattle may show enlarged lymph nodes and internal
organs.
 Hemolytic anemia is a characteristic sign.
 Systemic and reproductive disease are common in
cattle and appear to waste away.
 Horses with dourine show signs of ventral and genital
edema and urticaria.
 Infected dogs and cats may show severe systemic
signs.(fever, Red urine)
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9. PREVENTION AND TREATMENT
 Preventive measures are aimed at minimizing contact
with tsetse flies.
 Diminazene
 Homidium
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10. DX
 Parasites can easily be found in blood.
 They can also be found in lymph node fluid or in fluid
or biopsy of a chancre.
 Serologic testing is not widely available and is not used
in the diagnosis, since microscopic detection of the
parasite is straight forward.
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11. American Trypanosomiasis
( Chagas Disease)
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12.  Chagas disease is caused by the parasite Trypanosoma
cruzi.
 Infection is most commonly acquired through contact
with the feces of an infected triatomine bug (or "kissing
bug"), a blood-sucking insect that feeds on humans and
animals.
infection can also occur from:
 mother-to-baby (congenital),
 contaminated blood products (transfusions),
 an organ transplanted from an infected donor,
 laboratory accident, or
 contaminated food or drink (rare)
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13. Epidemiology
 Chagas disease is endemic throughout much of
Mexico, Central America, and South America
 The triatomine bug thrives under poor housing
conditions (for example, mud walls, thatched roofs) so
people living in rural areas are at greatest risk for
acquiring infection
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14. Life Cycle
 The protozoan parasite, Trypanosoma cruzi, a
zoonotic disease that can be transmitted to humans by
blood-sucking triatomine bugs.
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15. Disease
 Chagas disease has an acute and chronic phase. If
untreated, infection is lifelong.
 Acute Chagas disease occurs immediately after
infection
 may last up to a few weeks or months
 parasites may be found in the circulating blood.
 Infection may be mild or asymptomatic.
 There may be fever or swelling around the site of
inoculation.
 Acute infection may result in severe inflammation of
the heart muscle or the brain and lining around the
brain.
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16. Laboratory Diagnosis
It almost always yields positive results, and can be achieved by:
 Microscopic examination:
1. of fresh anticoagulated blood, or its buffy coat, for motile
parasites;
2. thin and thick blood smears stained with Giemsa, for
visualization of parasites.
 Isolation of the agent:
1. inoculation in culture with specialized media (e.g. NNN, LIT)
2. inoculation into mice
3. c) xenodiagnosis, where uninfected triatomine bugs are fed on
the patient's blood, and their gut contents examined for
parasites 4 weeks later.
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17. Durgs
 The two drugs used to treat infection with
Trypanosoma cruzi are
 nifurtimox
 benznidazole.
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18. Dosage and durationAge groupDrug
10 mg/kg per day orally in 2
divided doses for 60 days.
5-7 mg/kg per day orally in 2
divided doses for 60 days
< 12 years
12 years or older
Benznidazole
15-20 mg/kg per day orally in
3 or 4 divided doses for 90
days
12.5-15 mg/kg per day orally
in 3 or 4 divided doses for 90
days
8-10 mg/kg per day orally in
3 or 4 divided doses for 90
days
≤ 10 years
11-16 years
17 years or older
Nifurtimox
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