Gastroenteritis

Question 1

What are some GI infection risk factors?

Answer 1

• malnutrion
• closed communities
• exposure to contaminated food/water
• <5 years , not breastfeeding
• older age

Question 2

What is the bacterial effect of gastroenteritis?

Answer 2

• cellular invasion
• production of exotoxins
• changes in epithelial cell physiology
• loss of brush borders

Question 3

What defines diarrhoea?

Answer 3

• > 3 unformed stools/day

- stools hold shape of container

Question 4

What scoring system is used for diahorrea?

Answer 4

• bristol stool chart

Question 5

Explain dysentery

Answer 5

• inflammation of the intestine
• causing diarrhoea
• with blood and mucus

Question 6

What is important when taking a history with someone with diarrhoea?

Answer 6

• other symtoms
• description of stools
• travel
• food history

Question 7

What is the cause of traveler’s diarrhoea?

Answer 7

• eneterotoxgenic E.coli

Question 8

What bacteria is the cause of gastroenteritis after a course of antibiotics?

Answer 8

• c.difficile

Question 9

What may be the bacteria/virus that causes gastroenteritis in children or someone working in day care?

Answer 9

• rotavirus

Question 10

What is the most common bacteria involved in gastroenteritis?

Answer 10

• campylobacter jejuni

Question 11

What is the shiga toxin?

Answer 11

• inhibits protein synthesis
• causes cell death
• e.coli can produce the toxin

Question 12

Which toxin of shiga is most potent?

Answer 12

• toxin 2

Question 13

Should antibiotics be given to a patient with E.coli 0157?

Answer 13

• no

Question 14

What antigens are present on salmonella?

Answer 14

• O antigens

Question 15

What are the 2 most common viruses that cause gastroenteritis?

Answer 15

• norovirus

- rotavirus

Question 16

Explain rotavirus in terms of gastroenteritis?

Answer 16

• commonest cause in children
• person-faceal oral spread
• NOT BLOODY STOOLS

Question 17

Describe the rotavirus vaccine

Answer 17

• oral

- live attenuated

Question 18

Explain the norovirus in terms of gastroenteritis?

Answer 18

• winter vomiting bug
• person-person spread
• highly infectious

Question 19

When examinating a returned traveller what should you be looking for?

Answer 19

• fever
• rash
• hepatospenomegaly
• lymphadenopath
• insect bites

Question 20

Purfuse watery diarrhoea may be a sign of what?

Answer 20

• cholera

Question 21

What is enteric fever also called?

Answer 21

• typhoid fever

Question 22

What causes enteric fever?

Answer 22

• returning from India or SE Asia

- salmonella typhi

Question 23

What investigations should be done for amoebiasis?

Answer 23

• stool microscopy
• AXR (toxic megacolon)
• endoscopy

Question 24

Explain campylobacter

Answer 24

• gram negative
• s shaped
• motile

Question 25

Explain salmonella

Answer 25

- gram negative - enterobacteiaceae - bacilli

Question 26

Explain e.coli 0157

Answer 26

- E.coli --> gram neg rod shaped | - shiga toxin production

Question 27

low infectious doses makes spread_____

Answer 27

- easier

Question 28

Explain gastroenteritis?

Answer 28

- illness caused by eating contaminated food, with micororganiss toxins and posinos

Question 29

Large volume of diarrhoea more likely to be from the ____ bowel

Answer 29

- small

Question 30

Bacillus cereus found?

Answer 30

- starchy food | - reheated rice

Question 31

What is staphylococcus aures found in?

Answer 31

- milk/meat and fish

Question 32

What does the shigella toxin bind to and what affect does it have?

Answer 32

- the shigella toxin binds to receptors on renal cells and RBC, inhibiting protein synthesis and causing cell death

Question 33

What does E.coli bind to?

Answer 33

- binds to the absorptive enterocytes, causing cell death can also enter the blood stream

Question 34

Explain ETEC

Answer 34

- Enterotoxigenic E.coli | - heat stable toxin

Question 35

Explain EPEC

Answer 35

- Enteropathogenic E.coli - no toxin, not invasive - non-breastfed children

Question 36

Explain EIEC

Answer 36

- Enteroinvasive E.coli | - watery diarrhoea

Question 37

Explain EAIC

Answer 37

- Enteroaggreative E.coli | - traveller's diarrhoea

Question 38

Explain listeria monocytogenes

Answer 38

- 9-48hrs - unpasturised milk products, deli counter - gram +ve rod