Protozoa VII: Emerging Protozoa

Question 1

What are the cutaneous Leishmaniasis species?

Answer 1

Leishmania tropica (old world)
Leishmania mexicana (new world)
Leishmania braziliensis

Question 2

What are the visceral Leishmaniasis species?

Answer 2

Leishmania donovai complex

Leishmania infantum

Question 3

What is the sandfly spp. used as a vector for Leishmania in the new world?

Answer 3

Lutzomyia spp.

Question 4

What is the sandfly spp. used as a vector of Leishmania in the old world?

Answer 4

Phlebotomus spp.

Question 5

What is the Leishmania life cycle?

Answer 5

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

Question 6

What are the vertebrate hosts for Leishmania infantum outside the US?

Answer 6

Dogs, cats, jackals, foxes, horses, porcupines, other mammals

Question 7

What is the vertebrate host for Leishmania in the US?

Answer 7

Dogs

Question 8

What are the insect vectors for Leishmania infantum outside the US?

Answer 8

Sandflies

Question 9

What is the reservoir host for Leishmania infantum?

Answer 9

Dogs

Question 10

What is the PPP for canine leishmaniasis?

Answer 10

Variable

Question 11

What is used to diagnosis canine leishmaniasis?

Answer 11

Clinical signs and antibodies: serology
Staining: bone marrow, lymph aspirates, blood, touch preps
Culture or PCR

Question 12

What is used to detect canine leishmaniasis in other hosts?

Answer 12

Sand fly vectors: promastigotes

Other vertebrate hosts

Question 13

What are control methods for canine leishmaniasis with dog to dog transmission?

Answer 13

Ab test all dogs in hunt clubs with yearly testing

If dog Ab+: culture

Question 14

What are control methods for canine leishmaniasis with sand fly-vertebrate transmission?

Answer 14

Eliminate the sand fly through insecticides
Eliminate asymptomatic reservoir/vertebrate hosts
Create barriers between the insect vector and host

Question 15

What is the cause of human visceral leishmaniasis?

Answer 15

Leishmania donovani complex

Question 16

What is the most common form of human cutaneous leishmaniasis?

Answer 16

New world: L. mexicana

Old world: L. major, L. tropica

Question 17

What is the cause of human mucocutaneous leishmaniasis?

Answer 17

Leishmania braziliensis

Question 18

What is the vector of Trypanosoma cruzi?

Answer 18

Triatomine insect

Question 19

What are hosts of Trypanosoma cruzi in the US?

Answer 19

Domestic dogs
More than 20 wildlife species
Captive animals

Question 20

Describe Trypanosoma cruzi life cycle stages

Answer 20

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

Question 21

What is the Trypanosoma cruzi life cycle?

Answer 21

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

Question 22

What is the route of infection with Trypanosoma cruzi for triatomine insect?

Answer 22

Ingest trypomastigotes from blood meal from infected vertebrate host

Question 23

What is the route of infection with Trypanosoma cruzi for vertebrate host?

Answer 23

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

Question 24

What is the reservoir host of Trypanosoma cruzi?

Answer 24

Dog

Question 25

How do dogs become the reservoir host of Trypanosoma cruzi?

Answer 25

Infected directly by insect

Ingestion of infected bug or infected animal

Question 26

What is the incubation period of chagas in dogs?

Answer 26

Varies: about 3 days post-infection to 2-3 wweks

Question 27

Describe acute chagas in dogs

Answer 27

Lasts 10-30 days; fever, anorexia, diarrhea, lethargy, lymphadenopathy, hepatomegaly, splenomegaly, cardiac dysfunction, death

Question 28

Describe chronic chagas in dogs

Answer 28

Eventual congestive heart failure

Question 29

Describe latent chagas in dogs

Answer 29

Asymptomatic, low level infection, lasts for years

Question 30

What is the method of diagnosing Trypanosoma cruzi in animal hosts?

Answer 30

Blood smears: Giemsa stain (trypomastigotes)
Biopsy/histology: amastigotes in tissue
Culture
Serology

Question 31

What are methods of treatment for Trypanosoma cruzi?

Answer 31

Benznidazole, but it has severe side effects

Question 32

What does Trypanosoma brucei cause?

Answer 32

Nagana, African Sleeping sickness

Question 33

What is the species of Trypanosoma in horses?

Answer 33

T. equiperdum (venereal)

T. evansi