Hemoflagellates: Trypanosoma spp. University of Sulaimani School of Science Department of Biology Practical Parasitology 2 nd stage Lab 7 : Trichomoniasis
Objectives: Students should be able to: Identify developmental stages of the life cycle of Trypanosoma spp. Trypanosomiasis
List methods of diagnosis of Trypanosoma spp.
Trypanosomiasis Trypanosomiasis is a group of diseases caused Trypanosoma spp. in different location in the world.
(African Sleeping sickness)
Trypanosomiasis West-Africa trypanosomiasis: East-Africa trypanosomiasis :
Trypanosomiasis Major Vector-Borne Diseases
Anterior section – develops in anterior portions of digestive tract. Trypanosoma gambiense,T. rodesiense T. vivax; T. evansi, Stercoraria ( sterc/o feces) Posterior section – develops in hindgut of insect. Trypanosomes: Classification
T. cruzi; T. melophagium; T. lewisi
Amastigote (Leishmania) stage: Intracellular stage, replicate within cells of reticuloendothelial system; 2-4mm in diameter, spheroid or slightly oval, without flagella, may see > 100 amastigotes/cell.
Promastigote (Leptomonas stage): elongated or fusiform (from short and fat to long and thin) with flagella extending forward, the kinetoplastid located distally at the anterior end. without undulating membrane.
Epimastigot (C rithidia stage ): elongated with anterior flagella and undulating membrane. The kinetoplastid located near the nucleus.
Trypomastigote – in the blood stream; flagellum runs entire length from posterior. The K is posterior to the N. Trypanosomes: Morphology
Includes metacyclic (infective) stage in tsetse fly.
Polymorphic spindle-shaped parasites
Trypomastigotes in the blood stream
African Trypanosomiasis A systemic protozoal disease Organisms grow in blood, lymph, CSF, and intercellular spaces (in contrast to T. cruzi) Endemic in 36 countries and affects from 20,000 to 50,000 annually.
Untreated is universally fatal.
Trypanosoma gambiense G.D. : West and central Africa Disease: mid and west African sleeping sickness Habitat: extracellular parasite in blood and other body fluid of vertebrates.
Vector: tsetse fly ( Glossina palpalis )
Trypanosoma gambiense The Mouthpart of the Vector injected to the skin of the victim during a blood meal
Trypanosoma rhodesiense Disease: Rhodesian or east African sleeping sickness Habitat: extracellular parasite in blood and other body fluid of vertebrates.
Vector: tsetse fly ( Glossina morsitans )
Transmission Transmitted by Tsetse fly A pregnant women pass it to her fetus (rare) Through a blood transfusion (rare)
Trypanosoma gambiense African trypanosomiasis Taking up & injecting the infectious form:
Where patients live
Tissue phase: chancre
Winterbottom , s sign Enlarged cervical lymph nodes Hemolymphatic phase
Appear at the base of skull; sign of certain death according to slave traders.
Fluid aspirated from a chancre Concentrated of the blood buffy coat Diagnosis – Stage related
Double centrifugation technique .
American Trypanosomiasis Dr. Carlos Chagas Central and South America. Chagas Disease Trypanosoma cruzi typical C or S-shaped form.
Disease: American Trypanisomiasis or Chagas disease Habitat: Blood, tissue cell especially heart muscle, nerves, skeletal and smooth muscle of GIT by way of the blood and lymphatic system American Trypanosomiasis Triatoma infestans
Vector: triatomine bug (reduviid bug)
Kissing bugs ( Triatoma infestans ) transmit
not by inoculation but by faecal contamination .
Romaña sign: bipalpebral edema (unilateral)
Laboratory diagnosis Giemsa stained buffy coat blood smear Biopsy specimen – find Trypomastigotes and Amastigotes
Serology –, IHA, IFAT, ELISA,