Gastroenteritis

Question 1

E. coli

Answer 1

Commonest among travellers
Watery stools
Abdominal cramps and vomiting

Question 2

Giardiasis

Answer 2

Prolonged, non-bloody diarrhoea

Travel to developing countries; ?contaminated water

Question 3

Cholera

Answer 3

Profuse, watery diarrhoea
Severe dehydration –> weight loss
Not common in travellers
Contaminated water in Africa

Question 4

Shigella

Answer 4

Bloody diarrhoea

Vomiting + Abdominal Pain

Question 5

Staph Aureus

Answer 5

Severe vomiting

Found in cream - exotoxin –> Short incubation period

Question 6

Campylobacter

Answer 6

'flu-like prodrome followed by: 
- Crampy abdominal pain
- Fever
- Diarrhoea +/- blood
Complication: Guillain Barre

Question 7

Bacillus Cereus

Answer 7

Two types:

• Vomiting in less than 6 hours from rice
• Diarrhoea after 6 hours

Question 8

Amoebiasis

Answer 8

Gradual onset
Bloody Diarrhoea
Abdominal pain + tenderness
May last a few weeks 
Liver abscess; Rx metronidazole

Question 9

Which organisms have an incubation period of 1-6 hours?

Answer 9

Staph aureus + Bacillus cereus

Due to Preformed Toxin

Question 10

Which organisms have an incubation period of 12-48 hours?

Answer 10

Salmonella + E. coli

Question 11

Which organisms have an incubation period of 48-72 hours?

Answer 11

Shigella + Campylobacter

Question 12

Which organisms have an incubation period of > 7 days?

Answer 12

Giardiasis

Amoebiasis

Question 13

Which organisms have an incubation period of 1-9 days?

Answer 13

Cholera

Question 14

What is the general guideline behind treating gastroenteritis`

Answer 14

Supportive: (iv/oral) fluid rehydration

If bloody and systemic upset may warrant treatment

Question 15

How do you treat Campylobacter if systemic features?

Answer 15

Erythromycin or Ciprofloxacin

Question 16

How do you treat Salmonella (if systemic features)?

Answer 16

Ciprofloxacin

Question 17

How do you treat Giardiasis?

Answer 17

PO Metronidazole

Question 18

How do you treat Enterebius vermicularis?

Answer 18

PO mebendazole

Question 19

Clostridium perfringes

Answer 19

Normal gut flora but spores

Preformed toxin

Question 20

Salmonella typhi/paratyphi

Answer 20

Poor sanitation, water, food
Fever, ‘Rose spots’ + diarrhoea
14-21 days incubation

Question 21

How do you treat salmonella typhi/paratyphi?

Answer 21

Ceftriaxone OR Azithromycin OR Ciprofloxacin

Question 22

Helminth infections are often associate with?

Answer 22

Eosinophlia

Question 23

How are helminth infections diagnosed?

Answer 23

Adult worm or eggs passed in stool

Question 24

What are the most common intestinal nematodes?

Answer 24

Ascariasis

Question 25

What is the mechanism of intestinal nematode?

Answer 25

Invade tracheoalveolar tree, swallowed and then invade gut and produce eggs

Question 26

What are examples of trematodes (flukes)?

Answer 26

Schistosomiasis (fresh water exposure - acute/chronic infection) 
Liver flukes (Clonorchis/Fasciola) - SE Asia

Question 27

What are examples of cestodes (tapeworms)?

Answer 27

Taenia Solium (pork) or saginatum (beef) - acquired from undercooked meat containing infectious larval cysts
Taenia salium (autoinoculated or from human faeces) can cause cysticerlosis - tissue cysts in muscle and brain)

Question 28

What is Chagas Disease?

Answer 28

Transmitted by the kissing bug (triatomic)
Causes parasympathetic denervation affecting the colon or oesophagus
Megaoesophagus