Childhood diarrhoea in resource limited settings

Question 1

What are the risk factors for diarrhoea in children?

Answer 1

Malnutrition, children <5, immunosuppression, measles, lack of breast feeding, no immunisations, lack of access to safe water/sanitation/hygiene

Question 2

What is the classification of diarrhoea?

Answer 2

<7 days acute
7-14 days prolonged
>14 days persistent
>30 days chronic

Osmotic (osmotic pressure) vs secretory (toxin attaches to intestinal cells, allows secretion)

Inflammatory (bacterial) vs non inflammatory

Question 3

What are the most common causes of diarrhoea?

Answer 3

Virus: rotavirus (most common), noravirus, adenovirus, sarpovirus
Bacteria: shigella, salmonella, campylobacter, Ecoli
Parasites: guardia, cryptosporidium, micros-iridium, cyclospora, isospora, E.hystolitica, strongyloides

Prolonged diarrhoea - think parasites (micro parasites)

Question 4

Most common pathogens (top 6) causing diarrhoea

Answer 4

1. Shigella (not in first yr of life)
2. Rotavirus
3. Adenovirus
4. Enterotoxigenic E Coli (most common bacteria)
5. Cryptosporidum
6. Campylobacter

Question 5

How does Ecoli cause diarrhoea?

Answer 5

Virulence genes developed by Ecoli

Question 6

What is classic presentation of EPEC diarrhoea?

Answer 6

Prolonged diarrhoea - protein attaches to enterocyte

Question 7

Which type of EColi produces a HUS?

Answer 7

EHEC - causes HUS (Enterohemorrhagic Escherichia coli)

Question 8

Which type of Ecoli produces the same toxin as cholera?

Answer 8

Enterotoxigenic Ecoli - most common (like cholera - watery diarrhoea)

Question 9

Which of the Ecoli is associated with HIV?

Answer 9

EAEC - Enteroaggregative Ecoli

Question 10

Which of the Ecoli invades the cell?

Answer 10

EIEC - Enteroinvasive Escherichia coli

Question 11

Which pathogens cause prolonged and persistent diarrhoea?

Answer 11

EAEC, EPEC, parasites (coccidia)

Question 12

What are the differentials for watery diarrhoea?

Answer 12

Any!
Shigella, salmonella, campy
ETEC, EPEC
Rotavirus, noravirus
Cryptosporidium

Question 13

What are the causes of bloody diarrhoea?

Answer 13

shigella (most common), salmonella, campy, STEC

Question 14

Which of the causes of diarrhoea are most dehydrating?

Answer 14

Rotavirus, ETEC, cholera

Question 15

When do you need a microbiological diagnosis? What tests are available for diarrhoea investigation?

Answer 15

Prolonged diarrhoea or immunosuppressed

Special stains for coccidia (small parasites)
Microscopy
Stool cultures
Immunological. ELISA - lots available
PCR - needs to be quantitative!!! Otherwise would only identify colonisation
Tissue cultures

Question 16

What are the 3 critical signs of dehydration?

Answer 16

Thirst
Sensorium: irritable or comatose
Skin turgor: slow, very slow

Also: sunken eyes, dry membranes, absent tears

Question 17

What is the classification of diarrhoea?

Answer 17

Mild
Mod
Severe
(Based on % weight loss <5, 5-10, >10%)

Dehydration from diarrhoea class A/B/C

Question 18

How do you rehydrate a child with diarrhoea?

Answer 18

Mild: 100-200mls orally with each episode of diarrhoea - low osmolality solutions

Mod: 100ml/kg oral rehydration in 4 -6 hrs

Severe: Ringers lactate
Total 100ml/kg. If shocked give 20ml/kg immediately

<12 months - 30ml/kg in 1 hr, 70ml/kg over 5 hrs

> 12 months - over 30 mins, and 70ml/kg over 2.5 hrs

Question 19

How can you decrease the duration of diarrhoea?

Answer 19

Low osmolality solutions
Zinc

Question 20

When do you use antibiotics in diarrhoea?

Answer 20

Consider antibiotics for dysentery (bloody diarrhea with
fever)

Consider antibiotics for watery diarrhea with fever and
fecal leucocytes (> 50)

Antibiotics should cover Shigella