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Flashcards in GIT Helminths Deck (92)
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1

Anatomy of GIT

Mouth
Oesophagus
Stomach
Small intestines - duodenum, jejenum
Large inestines - ascending, transverse, descending
Rectum, anus
Liver, gall bladder, pancreas

2

Trematodes

Flukes
-Classify depending on location found
--- Blood flukes, liver flukes, lung flukes, intestinal flukes

3

Intestinal cestodes

Tapeworms
-- Species:
Taenia solium
T. saginata
Diphyllobothrium
Hymenolepis
Dipylidium caninum
Echinococcus
Spirometra
Taenia multiceps

4

Nematodes

Ascaris lumbricoides - ascariasis
Trichuris trichuria - whipworm - trichuriasis
Necator americanus + Ancylostoma duodenale - hookworms
Enterobius vermicularis - pinworm - entrobiasis
Strongyloides stercoralis - strongyloidiasis

5

Ascariasis - life cycle

Begins with eggs maturing in soil
human ingests eggs via food/drink/contaminated hands
Larvae burrow out of GI lumen into venous blood -> right heart -> lungs
Mature and live in lungs until coughed up
Then goes back to GIT

6

Why do ascaris prefer the lungs to develop?

Maybe higher O2 conc'n in lungs compared to GIT

7

Definitive host of acaris

humans; they mate there reaching final form

8

Why do they prefer hatching in soil?

Body temp too high

9

Risk factors - Ascariasis

Poor sanitation
Warm weather

10

Early illness ascariasis - symptoms due to

- lung migration

11

Late illness ascariasis - symptoms due to

- worm burden

12

Early infection - Eosinophils levels

When the body recognizes larvae moving in the blood, Eosinophilic levels rise in blood and lung tissue.

13

IgE - mediator of immune response causes what symptoms

--immune response causes transient cough, wheezing, chest pain, hemoptysis

14

Sputum sample

--Eosinophils in areas they shouldn't be in
or
--Charcot-Leyden Crystals (sign of high burden of Eosinophils)

15

Late infection of ascaris is often asymptomatic (T/F)

True

16

Diagnosis of Ascariasis

Colonoscopy findings, feces observation (OAP)

17

Symptoms - Ascariasis

nausea
Abd pain
Diarrhoea

18

Ascariasis fertilized eggs distinguished from unfertilized eggs, how?

 They are round rather than elongated and have a thicker cell wall.

19

Ascaris - fertilile egg

Round/ovoidal with thick shell; mammilated coat

20

Ascaris - infertile egg

Elongated, triangular, kidney shaped; thin shell; mammilated covering missing

21

Complications

Bowel blockage - heavy infection
Worms crawling to biliary tree - blocks biliary flow = biliary sepsis
Worms moving to peritoneum carrying fecal content - peritonitis

22

Treatment- Ascariasis

Albendazole, mebendazole, pyrantel
Surgery for obstruction

23

Trichuriasis - pathogen and egg shape

Trichuris trichiura
Long void, two clear bulbs on each end, football shaped

24

Trichuriasis transmission and complication

Soil; fecal oral
Rectal prolapse - occurs when rectum loses attachment to internal body and protrudes from anus

25

Trichuriasis pathogenesis

1. eggs are ingested and travel to the intestines
2. the larvae emerge and take up residence
3. They become either male or female adults
4. Adult worm resembles a bull whip - one side thick and other thin - thin side burrows into gut - fat end remains out in gut
5. Eggs passed into stool

26

Eggs sit in soil for 3-5 wks for maturation to become fertile (T/F)

True

27

Risk factors and treatment - Trichuriasis

Poor sanitation
Warm weather to nurture eggs
-Mebendazole + Albendazole

28

Clinical presentation - Trichuriasis -Illness severity correlates with worm burden (T/F)

True

29

Light infection symptoms - Trichuriasis

-Asymptomatic

30

Moderate infection symptoms - Trichuriasis

-Nausea
-Abd pain
-Diarrhoea