GI parasitic roundworms Flashcards Preview

Year 1 Microbiology > GI parasitic roundworms > Flashcards

Flashcards in GI parasitic roundworms Deck (28):
1

What are the properties of nematodes?

1. Non-segmented bodies 2. Separate sexes 3. Complete digestive system

2

What are the properties of cestodes?

1. Segmented bodies 2. Hermaphroditic 3. Absorb nutrients

3

What are the properties of trematodes?

1. Non-segmented (leaf-shaped) 2. Hermaphroditic 3. Primitive gut

4

What is required to shed eggs in a nematode infection?

A male and a female nematode

5

Do adult nematodes replicate in the host?

No

6

What are the two groups of geohelminths?

1. Ascaris and trichuris - ingestion of infectious eggs 2. Strongyloides and hookworms - penetration of skin by infectious larvae in soil

7

What is the genus and species of pinworm?

Enterobius vermicularis

8

What is the treatment for pinworms?

Mebendazole, pyrantel pamoate - single dose, repeated two weeks later

9

What is the genus and species of whipworm?

Trichuris trichiura

10

What are the symptoms of whipworm infection?

1. Heavy worm burden 2. Bloody, mucous containing diarrhea 3. Frequent stools 4. Rectal prolapse in children

11

What is the organism associated with ascariasis?

Ascaris lumbricoides

12

What are the characteristics of pulmonary disease associated with ascariasis?

1. Combination of physical presence of larvae and immune response to them 2. Mild cough, pneumonitis 3. Parasite antigens highly allergenic 4. Eosinophilia

13

What is the diagnosis for ascariasis?

1. Eggs in stool 2. Larvae or eosinophilia in sputum

14

What are the genus and species names of hookworm?

1. Necator americanus 2. Ancylostoma duodenale

15

What is the life cycle of hookworms?

1. Infective larvae penetrate skin from soil 2. Circulation - lungs - trachea - pharynx - swallowed 3. Adults attach to small intestine 4. Diagnostic stage - eggs in feces

16

What are the clinical manifestations of hookworm infection?

1. Iron-deficiency anemia due to blood loss from hookworm feeding 2. Moderate dermatitis at site of penetration 3. Pnuemonia and eosinophilia

17

What is the cause of strongyloidiasis?

Strongyloides stercoralis

18

What are the features of strongyloidiasis?

1. Facultative parasite - can be a free living nematode in soil 2. Larvae passed in stool 3. Worms produce eggs in soil, not intestines 4. Infectious larval form can develop in intestine, enter circulation, and re-initiate infection

19

What is the main cause of strongyloides hyperinfection and disseminated disease?

Immunosuppression

20

What is the diagnosis for strongyloidiasis?

Larvae in stool

21

Which nematode egg is flat on one side?

Enterobius vermicularis - pinworm

22

Which nematode egg is lemon / barrel shaped?

Trichuris trichiura - whipworm

23

Which nematode egg is lumpy / bumpy?

Ascaris lumbricoides

24

Which nematode egg is "boring / plain"?

Hookworm (necator americanus, ancylostoma duodenale)

25

Enterobius vermicularis (pinworm) has what kind of egg morphology?

Flat on one side

26

Trichuris trichiura (whipworm) has what kind of egg morphology?

Lemon / barrel shaped

27

Ascaris lumbricoides has what kind of egg morphology?

Lumpy / bumpy

28

Hookworm eggs have what type of morphology?

"Boring / plain"