Leishmania and Trypanosoma Parasites

Question 1

Life cycle: Vector- Phlebotomus sand fly. Human host - multiplication in macrophages
Route of infection: Vector- regurgitation of infective promastigote forms
Geography: L. tropics - Urban - urban Middle East settings, Afghanistan, India, former USSR, and Turkey. L. major- Rural - Middle East, Afghanistan, Africa. L. aethiopica - Ethiopia
Specimen samples: aspirates, scrapings, biopsies
Lab tests: Methonal fixed, Giemsa stained - amastigotes in the macrophages, 3-5 mcm. Monoclonal antibodies, DNA probes/PCR testing, Novy, MacNeal, and Nicolles (3N) culture media, isoenzyme electrophoresis analysis of cultured parasites, leishmanin skin test (LST)(Montenegro test), serological tests for research or epidemiology
Pathology: L. tropica - Oriental sore, tropical sore, or Old Wold Cutaneous Leishmaniasis. Skin ulcertaitons - self healing. L. major - self healing sore

Answer 1

Leishmania tropica, L. major, and L. aethipica

Question 2

Life cycle: same as L. tropica.
Route of infection: Vector - Lutzomyia
Geography: L. mexicana - southern Texas to South America. L. braziliensis - Many areas of South America
Specimen samples: aspirates, scrapings, biopsies
Lab tests: Methonal fixed, Giemsa stained - amastigotes in the macrophages, 3-5 mcm. Monoclonal antibodies, DNA probes/PCR testing, Novy, MacNeal, and Nicolles (3N) culture media, isoenzyme electrophoresis analysis of cultured parasites, leishmanin skin test (LST)(Montenegro test), serological tests for research or epidemiology
Pathology: L. mexicana - New World Cutaneous - skin lesions. L. braziliensis - Espundia. Nose cartilage disfigured

Answer 2

L. mexicana and L. braziliensis

Question 3

Life cycle: The same as other L. species except the macrophages can be found throughout the body
Route of Infection: Phlebotomus sand fly, blood transfusions, sexual contact
Geography: India, Middle East, Brazil
Specimen sample: bone marrow and liver, if large amounts peripheral blood
Lab test: Biopsies, amastigotes in macrophages. Culture media - 3N media (Novy, MacNeal, Nicolle), PCR, rk39 antigen test- immunochromatographic test, formol-gel test (a drop of formaldehyde, 1 mL serum=turns to gel)
Pathology: Kala azar, Dum Dum fever. Fever, headache, weakness, progressive anemia, anorexia. Kala azar - darkened skin. Co-infection with HIV seen in France, Spain, Italy

Answer 3

Leishmania donovani

Question 4

Life cycle: Vector- tsetse fly (Glossina species). Humans - trypomastigotes in blood, lymph, CSF
Route of infection: Anterior transmission
Geography: T. brucei gambiense - Western Africa. T. brucei rhodesiense - Easter Africa
Specimen source: blood sample
Morphology: 15-30 mcm, trypanosomes
Lab test: Thick and thin films
Pathology: African Sleeping Sickness. Winterbottom’s sign, fever, headache, coma

Answer 4

Trypanosoma brucei gambiense and Trypanosoma brucei rhodiesiense

Question 5

Life cycle: Vector - Reduviid buy (kissing bug). Humans - trypomasitgotes circulate in blood
Route of infection: Posterior transmission, blood transfusions
Geography: Central and S. America
Specimen source: blood sample
Morphology: Trypanosomes, C-shaped, size; ~20 mcm long
Lab tests: thick(Giemsa stained) and thin (Wright-Giemsa stained) peripheral blood films/smears. immunoassay - tested in donated blood, xenodiagnosis serology - Machado complement fixation test, PCR, Novy, MacNeal, and Nicolle’s media (3N) media
Pathology: Chagas’ disease; cardiomyopathy, megacolon, megaesophagus; Chagoma - initial swelling, Romana’s sign

Answer 5

Trypanosoma cruzi