Infective Diarrhoea

Question 1

What is diarrhoea?

Answer 1

• frequent evacuation of liquid stools
• accompanied by loss of fluid and electrolytes.
• Occurs when food moves through SI rapidly
• decreased absorption of fluids
• increased secretion of fluids into GI tract.

Question 2

Causes of diarrhoea?

Answer 2

1) inflammatory disease
2) medications
3) over-consumption of sugars
4) malnutrition
5) insufficient or damaged mucosal absorptive surface
6) bacterial/fungal/viral infections

Question 3

How diarrhoea is diagnosed?

Answer 3

stool:
- for blood
- osmolarity and electrolyte composition
- bacterial contamination
- fecal fat

Question 4

What bacterial species is the most common cause of infectious diarrhoea?

Answer 4

Campylobacter spp.

Question 5

What type of bacteria is Campylobacter spp?

Answer 5

Gram negative, S-shaped rod

Question 6

What type of bacteria is salmonella?

Answer 6

Gram-negative, rod shaped, flagellated, aerobic

Question 7

How does salmonella cause diarrhoea?

Answer 7

1) once ingested, it’s absorbed into epithelial cells in the terminal part of the SI
2) it penetrates cells and migrates to lamina propria layer of ileocecal reagion (ileum/cecum region)
3) multiplies in lyphoid follicles causing reticuloendothelial hyperplasia and hypertrophy.
4) polymorphonuclear leukocytes confine infection to GI tract
5) inflammatory response mediates release of prostaglandins
6) prostaglandin stimulates cAMP and active fluid secretion
7) diarrhoea

Question 8

What type of bacteria is E.coli?

Answer 8

Gram-negative, facultative aerobic, rod-shaped

Question 9

How does E.coli cause diarrhoea?

Answer 9

Enterotoxins released cause cAMP to increase, causing Cl- secretion to increase, causing H20 and Na+ secretion to increase. So fluid and electrolytes.

Question 10

How to treat food poison?

Answer 10

• symptoms pass within a week
• rest and drink a lot of fluids to prevent dehydration
• eat small light meals.

Question 11

When do you use antibiotics to treat food poisoning?

Answer 11

• when symptoms are severe
• when immune system is compromised
• when symptoms worsen
• when diarrhoea lasts for more than a week

Question 12

What is C.diff

Answer 12

Clostridium difficile:

• gram positive
• spore forming
• anaerobic
• motile
• prevalent in soil

Question 13

What can cause C.diff?

Answer 13

• eating soil
• in contact with someone else who has it
• using antibiotics (a lot)