Lecture 2 - Trypanosomes (Haemoflagellates)

What is the order, family, and genus of trypanosomes?

-Order: Kinetoplastida

-Family: trypanosomatidae

-Genus: Trypanosoma/Leishmania

What do trypanosomes contain cellularly that allow for diagnosis? What is its function?

Kinetoplast - rudimentary mitochondria

What is a? Where is it found? What species is it found in?

-Amastigote stage

-Intracellular form

-Found in Leishmania and T. cruzi

What is b? Where is it found? What species is it found in?

-Promastigote stage

-Extracellular form found in insects

-Leishmania

What is c? Where is it found? What species is it found in?

-Epimastigote

-Extracellular form found in insects

-Trypanosomes (except leishmania)

What is d? Where is it found? What species is it found in?

-Trypomastigote

-Extracellular in blood stream

-Both Leishmania and Trypanosomes

What are the three African Trypanosomes of veterinary importance?

1. Trypanosoma brucei brucei

2. Trypanosoma congolense

3. Trypanosoma vivax

How is Trypanosoma brucei brucei transmitted? Who does it affect? What is the reservoir?

-Transmitted by tsetse flies

-Affects livestock and humans

-Wildlife (buffalo) reservoirs

How is Trypanosoma congolense transmitted? Who does it affect? What is the reservoir?

-Transmitted by tsetse flies

-Affect livestock (particularly cattle)

-Wildlife (buffalo) reservoirs

How is Trypanosoma vivax transmitted? 

-Transmitted by tsetse flies and hematophagus dipterans

For the African trypanosomes, what are the clinical signs?

-Anemia

-Intermittent fever

-Edema

-Chronic wasting

-Swollen lymph nodes

-Death

How are the african trypanosomes diagnosed?

-Giesma stain of blood smear

-Lymph node biopsy

-ELISA test

-PCR

What is the treatment and control for the African Trypanosomes?

-Treatment: diminazene aceturate, melarsomine dichlorhydrate, suramin, isometamidium chloride

-Control: insecticide treated traps

What is the life cycle of Trypanosoma evansi? What is its distribution? What animals does it affect?

-Life cycle: transmitted by biting flies, vampire bats are reservoirs (S. America)

-Distribution: Africa, Asia, Central and South America

-Animals affected: horses, mules, buffalo, deer, camels, llama, cattle

What are the clinical signs of Trypanosoma evansi? What is the diagnosis? What is the treatment?

-Clinical signs: nervous signs, weight loss, progressive anemia, icterus

-Diagnosis: Giesma stain of blood smear or lymph node biopsy, ELISA tests, PCR

-Treatment: Diminazene aceturate, melarsomine, suramin

What is the distribution, species affected, and transmission of Trypanosoma equiperdum?

-Distribution: South America, Africa, Middle East

-Species affected: horses, donkeys, mules, zebras

-Transmission: sexually

What are the clinical signs, diagnosis and treatment of Trypanosoma equiperdum?

-Signs: mucopurulent vaginal discharge, vulvitis and vaginitis with polyuria, edema in the prepuse, neurological signs

-Diagnosis: collect urethral/vaginal discharges and centrifuge, collect blood in anticoagulant and look at buffy coat, or run complement fixation test using animal serum

-Treatment: Eymelarsan, euthanasia

What is the distribution of Trypanosoma cruzi? What are the three forms? What are the affected species?

-Distribution: South and Central America, some parts of Southern US

-3 forms: Amastigote, Trypomastigote, Epimastigote

-Species: humans, canines, wildlife reservoir

What are the clinical signs of the acute phase in Trypanosoma cruzi? Chronic phase?

-Acute phase: fever, localized/generalized lymphadenopathy, splenomegaly, hepatomegaly, anorexia, vomiting, diarrhea, lethargy

-Chronic phase: right-side CHF, myocarditis, arrhythmias, bilateral cardiac dilation

What is the diagnosis and treatment of trypanosoma cruzi?

-Diagnosis: travel history, Giesma stain of blood smear or lymph node biopsy, serology, PCR, culture

-Treatment: Benznidazole (not available in the US)