21. Cholera

Question 1

WHO definition of diarrhoea

Answer 1

the passage of 3 or more liquid stools per day

Question 2

Three clinical types of diarrhoea:

Answer 2

Acute watery diarrhoea – lasting several hours or days, such as cholera

Acute bloody diarrhoea – also called dysentery

Persistent diarrhoea – lasting 14 days or longer

Question 3

Describe the main modes of transmission of infective diarrhoea

Answer 3

Water contaminated with human/animal faeces

Poor personal hygiene

Food prepared or stored in unhygienic conditions

Fish and seafood from polluted water may also contribute infective diarrhoea

Question 4

Campylobacter

Answer 4

Milk, Poultry, animal contact

Question 5

Clostridium difficile

Answer 5

Hospital

Question 6

Clostridium perforingens

Answer 6

Meat, poultry, fish

Question 7

Escherichia coli

Answer 7

Food, water, undercooked beef, cheese, person-person

Question 8

Mycobacterium tuberculosis

Answer 8

Contaminated milk, respiratory infection

Question 9

Salmonella

Answer 9

Milk, beef, eggs, poultry

Question 10

Shigella

Answer 10

Person to person

Question 11

Vibrio cholera

Answer 11

Water, shellfish, person-person

Question 12

Yersinia enterocolitica

Answer 12

Milk, pork

Question 13

Pathogenesis of diarrhoea

Answer 13

V. cholera survives stomach acid

V. cholera colonises S.I using a pilus

V. cholera produces an enterotoxin

enterotoxin binds to receptors on immature enterocytes of the crypts

Increased levels cAMP

Increased chloride secretion

Decreased Sodium absorption

Massive fluid and electrolyte shift into the lumen

Question 14

Sodium

Answer 14

High due to dehydration

Question 15

Potassium

Answer 15

Low, lost in diarrhoea

Question 16

Urea

Answer 16

High, markers of dehydration and acute kidney injury

Question 17

Creatinine

Answer 17

High

Question 18

Management of dehydration in adults

Answer 18

Give an IV fluid bolus of a crystalloid and reassess

If improved give further fluid up to 2L quickly

Catheterize patient to accurately monitor urine output

Encourage oral rehydration with rehydration salts

If no improvement after 2L fluid, consider intensive care with a central venous line, and more aggressive fluids therapy.