Para - American Trypanosomes

Question 1

What parasite is responsible for American trypanosomiasis?

Answer 1

Trypanosoma Cruzi

Question 2

Definitive host for Chagas’ disease

Answer 2

Man

Question 3

RH of Chagas’ disease

Answer 3

Dogs
Cats
Rodents
Armadillos

Question 4

IH of Chagas’ disease

Answer 4

Triatoma megista

Question 5

Morphological form and habitat in acute stage

Answer 5

Monomorphic trypomastigote, extracellularly in blood

Question 6

Morphological stage and habitat in chronic stage

Answer 6

Amastigote, intracellular in tissues and muscles

Question 7

Describe habitat and appearance of monomorphic trypomastigote

Answer 7

Found in blood of patients

C or U shaped

20 um

Has flagellum

Question 8

Describe the habitat and appearance of epimastigote

Answer 8

Found in midgut of vector and in culture

10-20 um

Has flagellum

Question 9

Describe habitat and appearance of metacyclic trypomastigote

Answer 9

Found in hind gut and stool of the vector

15 um

No flagellum

Question 10

Describe habitat and appearance of amastigote

Answer 10

Found intracellular

2-6 um

Question 11

Name the type of transmission inside vector

Answer 11

Biological cyclopropagative

Question 12

Diagnostic stages

Answer 12

1. Monomorphic trypomastigote in blood ( acute stage )
2. Epimastigotes in culture
3. Amastigotes in tissues ( chronic stage )

Question 13

Infective stage

Answer 13

Metacyclic trypomastigote

Question 14

How long is acute stage

Answer 14

1-4 months

Question 15

Clinical picture in acute stage

Answer 15

Chagoma

Romana sign

Question 16

What is chagoma

Answer 16

Erythematous indurated area

Question 17

What is romana sign

Answer 17

Purple swelling of lids of one eye

Caused when parasite meters through skin or mucus membrane

Question 18

Incubation period of disease

Answer 18

1- 2 weeks

Question 19

Clinical picture of chronic stage

Answer 19

Chagas cardiomyopathy

Chagas digestive disease

Question 20

Describe Chagas cardiomyopathy

Answer 20

1- Arrythmia
2- Conductive defects
3- Dilated cardiomyopathy
4- Congestive heart failure

Question 21

Describe Chagas digestive disease

Answer 21

Megaoesophagus
Megacolon

Manifested by :
1. Difficulty swallowing
2. Regurgitation
3. Chronic constipation
4. Loss of weight

Question 22

Direct methods of diagnosis

Answer 22

Blood films stained by Giemsa

Culture

Histopathalogical examination

Question 23

What is seen in blood films

Answer 23

Trypomastigote in blood (acute stage only)

Question 24

What is seen in blood culture

Answer 24

Epimastigotes

Question 25

What is seen in Histopathological examination

Answer 25

Amastigotes

Question 26

Imaging methods

Answer 26

- Chest X-ray - Echocardiogram - Electrocardiogram

Question 27

Imaging methods

Answer 27

- Chest X-ray - Echocardiogram - Electrocardiogram

Question 28

Treatment options in the acute stage

Answer 28

Benznidazole & Nifurtimox

Question 29

Prevention and control methods

Answer 29

1. Vector control 2. Bed nets 3. Avoid pets 4. Screening of blood donors 5. Testing of organs, tissue or cell donors 6. Screening of newborns & children of infected mothers for early diagnosis and treatment 7. Health education

Question 30

Why can’t T.cruzi be eradicated in latent America

Answer 30

It has a large number of RH

Question 31

Describe life cycle of triatoma megista

Answer 31

Incomplete metamorphosis - Egg to Nymph to Adult

Question 32

Describe morphology of triatoma megista

Answer 32

- 2-3 cm - Dark brown or black in colour with reddish markings on thorax or abdomen

Question 33

What insecticide is effective against triatoma megista?

Answer 33

Malathion