Protozoa VII: Emerging Protozoa Flashcards
What are the cutaneous Leishmaniasis species?
Leishmania tropica (old world) Leishmania mexicana (new world) Leishmania braziliensis
What are the visceral Leishmaniasis species?
Leishmania donovai complex
Leishmania infantum
What is the sandfly spp. used as a vector for Leishmania in the new world?
Lutzomyia spp.
What is the sandfly spp. used as a vector of Leishmania in the old world?
Phlebotomus spp.
What is the Leishmania life cycle?
Sand fly ingests amastigotes during blood meal— amastigotes transform to promastigotes and divide— metacyclic promastigotes migrate to sand fly probscis to enter vertebrate host during next blood meal
Vertebrate host is bitten by sand fly— promastigotes are injected during blood meal— phagocytized by macrophages— transform to amastigotes— divide by binary fission inside macrophages— lyse macrophage— invade new cells
What are the vertebrate hosts for Leishmania infantum outside the US?
Dogs, cats, jackals, foxes, horses, porcupines, other mammals
What is the vertebrate host for Leishmania in the US?
Dogs
What are the insect vectors for Leishmania infantum outside the US?
Sandflies
What is the reservoir host for Leishmania infantum?
Dogs
What is the PPP for canine leishmaniasis?
Variable
What is used to diagnosis canine leishmaniasis?
Clinical signs and antibodies: serology
Staining: bone marrow, lymph aspirates, blood, touch preps
Culture or PCR
What is used to detect canine leishmaniasis in other hosts?
Sand fly vectors: promastigotes
Other vertebrate hosts
What are control methods for canine leishmaniasis with dog to dog transmission?
Ab test all dogs in hunt clubs with yearly testing
If dog Ab+: culture
What are control methods for canine leishmaniasis with sand fly-vertebrate transmission?
Eliminate the sand fly through insecticides
Eliminate asymptomatic reservoir/vertebrate hosts
Create barriers between the insect vector and host
What is the cause of human visceral leishmaniasis?
Leishmania donovani complex
What is the most common form of human cutaneous leishmaniasis?
New world: L. mexicana
Old world: L. major, L. tropica
What is the cause of human mucocutaneous leishmaniasis?
Leishmania braziliensis
What is the vector of Trypanosoma cruzi?
Triatomine insect
What are hosts of Trypanosoma cruzi in the US?
Domestic dogs
More than 20 wildlife species
Captive animals
Describe Trypanosoma cruzi life cycle stages
Single, large mitochondria (kinetoplast) Undulating membrane Single nucleus Either elongate with a single flagellum or rounded with a short, nonprotruding flagellum 1. Trypomastigote 2. Epimastigote 3. Amastigote
What is the Trypanosoma cruzi life cycle?
Trypomastigotes ingested by triatomine vector during blood meal of infected vertebrate host— develop into epimastigotes in triatomine gut— multiply— differentiate into metacyclic trypomastigotes— exit feces of triatomine insect vector— entry into vertebrate host— trypomastigotes enter vertebrate host cell and transform into amastigotes— replicate— diferentiate into trypomastigotes— circulate and invade new cells OR lie dormant as amastigotes
What is the route of infection with Trypanosoma cruzi for triatomine insect?
Ingest trypomastigotes from blood meal from infected vertebrate host
What is the route of infection with Trypanosoma cruzi for vertebrate host?
Via triatomine insect vector
-Trypomastigotes in triatomine feces enter wound/mucosal membrane
-Host ingest infected triatomine insect or food contaminated with infected triatomine feces
Transplacental
Blood: transfusion, needles; organ transplant
What is the reservoir host of Trypanosoma cruzi?
Dog
How do dogs become the reservoir host of Trypanosoma cruzi?
Infected directly by insect
Ingestion of infected bug or infected animal
What is the incubation period of chagas in dogs?
Varies: about 3 days post-infection to 2-3 wweks
Describe acute chagas in dogs
Lasts 10-30 days; fever, anorexia, diarrhea, lethargy, lymphadenopathy, hepatomegaly, splenomegaly, cardiac dysfunction, death
Describe chronic chagas in dogs
Eventual congestive heart failure
Describe latent chagas in dogs
Asymptomatic, low level infection, lasts for years
What is the method of diagnosing Trypanosoma cruzi in animal hosts?
Blood smears: Giemsa stain (trypomastigotes)
Biopsy/histology: amastigotes in tissue
Culture
Serology
What are methods of treatment for Trypanosoma cruzi?
Benznidazole, but it has severe side effects
What does Trypanosoma brucei cause?
Nagana, African Sleeping sickness
What is the species of Trypanosoma in horses?
T. equiperdum (venereal)
T. evansi
