protozoa - flagellates - hemoflagellates

Question 1

where do hemoflagellate live

Answer 1

in the bloodstream and tissues

Question 2

trypanosomes morphology

Answer 2

elongated, spindle-shaped
flagellum
undulating membrane
single nucleus
kinetoplast

Question 3

hemoflagellate life stages

Answer 3

-amastigote
-trypomastigote
-promastigote
(not all life stage types are present in all trypanosomes)

Question 4

what life stages occur in vertebrate hosts

Answer 4

amastigote and trypomastigote

Question 5

what life stages occur in invertebrate hosts

Answer 5

promastigote

Question 6

amastigote

Answer 6

non-motile
no visible flagellum
replicates in tissues

Question 7

trypomastigote

Answer 7

infective form in some species
flagellum

Question 8

promastigote

Answer 8

infective form in some species
flagellum

Question 9

trypansomes transmission

Answer 9

-arthropod vector: arthropod bites mammal host and ingests trypomastigote in blood

1. salivarian transmission - when insect bites host
2. stercorarian transmission - arthropod feces

Question 10

trypanosoma cruzi host

Answer 10

dogs; all mammals

Question 11

trypanosoma cruzi morphology

Answer 11

in bloodstream:
-trypomastigotes = spindle-shaped, single flagellum, undulating membrane, nucleus and kinetoplast

in macrophages and cardiac myocytes:
-amastigotes = intracellular, oval-shaped, no flagellum

Question 12

trypanosoma cruzi reservoir

Answer 12

wild mammals (raccoons, opossums, armadillos)

Question 13

trypanosoma cruzi source

Answer 13

arthropod vector (triatoma bugs)

Question 14

trypanosoma cruzi transmission method

Answer 14

stercorarian transmission to dog/mammals or oral ingestion of infected triatoma bugs

trypomastigote invades cardiac myocyte and turns into amastigote and divides then turn back into trypomastigote

infected myocyte ruptures and trypomastigote released into host blood stream

Question 15

trypanosoma cruzi clincial signs

Answer 15

acute phase:
-within a couple weeks after infection
-cardiac failure (arrhythmias, myocarditis, dilated cardiomyopathy)
- can be fatal

latent phase:
-if host survives acute phase; asymptomatic

chronic phase:
-months after infection
-cardiac failure

Question 16

trypanosoma cruzi patho

Answer 16

-trypomastigotes invade cardiac myocytes - INTRACELLULAR
-amastigote replication in cells damage the cell
-host immune response –> INFLAMMATION
-progressive cardiac damage

Question 17

trypanosoma cruzi diagnosis

Answer 17

-clinical signs: heart failure (ECG changes, thoracic imaging)
-cytology: trypomastogtes in stained blood films (acute stage)
-serologic tests: antibody detection (ELISA, IFA)

Question 18

trypanosoma cruzi treatment/prevention

Answer 18

-drugs are not easily available
-supportive therapy for cardiac disease

-reduce exposure to vectors

Question 19

trypanosoma cruzi zoonotic?

Answer 19

-not directly to people from mammals
-triatoma bug vector required
-dogs are a possible reservoir for human inf.

Question 20

Leishmania host

Answer 20

dogs, people
less common - cats, horses, other animals

Question 21

Leishmania morphology

Answer 21

in mammal host
-in macrophages: amastigotes - oval shaped, no flagellum
-in sand fly vector: promastigoTes - flagellum

Question 22

Leishmania arthropod vector

Answer 22

sand flies

Question 23

Leishmania transmission

Answer 23

-salivarian transmission (promastigotes) to dog via sandy fly bite
-promastigote invades macrophages
-promastigote turn into amastigote
-divides, infected macrophage ruptures, amastigotes infect other cells/macrophages
-

Question 24

Leishmania source

Answer 24

bite of sand fly carrying Leishmania

Question 25

Leishmania clinical signs

Answer 25

-cutaneous lesions: dermatitis, skin ulceration
-visceral/systemic signs: lymphadenomegaly, weight loss/muscle wasting, lethargy, splenomegaly, GI signs
-immune response leads to –> kidney failure, epistaxis, ocular disease

-may not be seen for months to years following infection

Question 26

Leishmania patho

Answer 26

-phagocytized by macrophages (as promastigotes)
-multiply in macrophages (as amastigotes)
-disseminate to … hemolymphatic organs and skin
-chronic disease

Question 27

Leishmania diagnosis

Answer 27

-antibody testing (serology)
-PCR
-visualization of amastigotes: cytology, biopsy

Question 28

Leishmania treatment

Answer 28

-drugs available (must report infected dog to CDC)
-difficult: months of treatment; rarely eliminated
-relapses common

Question 29

Leishmania control and prevention

Answer 29

-keep dogs indoor during sandfly season
-prevent sandfly bites (topical insecticides for dogs)
-vaccine (one available)

Question 30

Leishmania zoonotic?

Answer 30

-nothing documented from dogs to people
-sand fly vector required
-humans can be infected via bite of infected sandfly