3.5 Gastroenteritis

Question 1

8 differential diagnoses for diarrhoea / loose stools?

Answer 1

• infection (gastroenteritis)
• IBD
• lactose intolerance
• coeliac disease
• CF (+steatorrhoea)
• Toddler’s diarrhoea
• IBS
• meds eg Abx

Question 2

Viral causes of diarrhoea?

Answer 2

Viral:

• rotavirus
• norovirus
• (adenovirus, more subacute diarrhoea)

Question 3

Bacterial causes of diarrhoea?

Answer 3

Bacterial:

• E. coli
• Campylobacter jejuni
• Shigella
• Salmonella
• Bacillus cereus
• Yersinia enterocolitica
• Staph aureus toxin
• Giardiasis (parasite)

Question 4

How can you spread E. coli?

Answer 4

• infected faeces, unwashed salad, contaminated water

(normal intestinal commensual)

Question 5

What strain of E. coli is worst and why?

Answer 5

• 0157 strain produces Shiga toxin

Question 6

What does the shiga toxin from O157 E. coli do?

Answer 6

• Shiga toxin destroy RBCs and leads to haemolytic uraemia syndrome (HUS)

Question 7

Along with shiga toxin what else increases the risk of HUS in E. coli gastroenteritis?

Answer 7

• Abx increase HUS risk

AVOID Abx in E. coli

Question 8

What is the most common bacterial cause of gastroenteritis worldwide?

Answer 8

Campylobacter jejuni

Question 9

What causes travellers diarrhoea?

Answer 9

Campylobacter jejuni

Question 10

How can you get Campylobacter jejuni gastroenteritis?

Answer 10

• raw / undercooked poultry, untreated water, unpasteurised milk

Question 11

What is a typical presentation / symptoms of Campylobacter jejuni gastroenteritis?

Answer 11

• cramps
• diarrhoea maybe with blood,
• vomit
• fever

incubate 2-5, Sx resolve after 3-6days

Question 12

If you isolate Campylobacter jejuni what should you consider giving?

Answer 12

severe symptoms or HIV or heart failure, then treat:

Abx: azithromycin or ciprofloxacin

Question 13

How is shigella spread?

Answer 13

• faeces in drinking water or swimming pool or food

Question 14

Typical symptoms and course of shigella?

Answer 14

• bloody diarrhoea, cramps and fever
• 1-2 days incubation, Sx resolve in a week

Question 15

What can the toxin from shigella cause?

Answer 15

shiga toxin (like O157 e. coli)

causes HUS

Question 16

How would you treat severe cases of shigella?

Answer 16

Abx: azithromycin or ciprofloxacin

Question 17

How is salmonella spread / aquired?

Answer 17

• raw eggs or poultry, or reptile infected food

Question 18

Typical salmonella symptoms and course?

Answer 18

• watery diarrhoea maybe mucous or blood
• incubation 12hr to 3days and Sx resolves in 1week
• abx only in severe and guided by stool C+S

Question 19

How is Bacillus cereus spread / acquired?

Answer 19

• inadequately cooked food / not refrigerated eg rice
• gram +ve rod

Question 20

What causes you to cramp and vomit with 5hrs of Bacillus cereus infection?

Answer 20

• cereulide toxin; cramp and vomit within 5hours

Question 21

What is the typical course / symptoms of Bacillus cereus?

Answer 21

• cereulide toxin; cramp and vomit within 5hours
• watery diarrhoea within 8hrs
• resolves within 24hrs

classic course so exam worthy

Question 22

If Bacillus cereus is a gram +ve rod, what is a gram -ve bacillus?

Answer 22

Yersinia enterocolitica

Question 23

How do you spread / acquire Yersinia enterocolitica?

Answer 23

• pigs, so undercooked pork
• urine or faeces of rats / rabbits

Question 24

Typical course / symptoms of Yersinia enterocolitica?

Answer 24

• 4 to 7 days incubation
• watery or bloody , fever, pain
• lymphadenopathy

Question 25

How can Yersinia enterocolitica present in older children / adults?

Answer 25

fever and right sided abdo pain = mesenteric lymphadenitis (gives appearance of appendicitis)

Question 26

What else can, like Bacillus cereus, see recovery within 24hrs?

Answer 26

STAPH AUREUS TOXIN: - enterotoxins on eggs, diary or meat - start within hours and settle within 12 to 24 - D+V, cramps, fever

Question 27

How do you diagnose and treat giardia?

Answer 27

- stool microscopy - metronidazole

Question 28

Key facts about each of the bacterial causes of gastroenteritis? - E. coli - Campylobacter jejuni - Shigella - Salmonella - Bacillus cereus - Yersinia enterocolitica - Staph aureus toxin - Giardiasis (parasite)

Answer 28

E. COLI: - infected faeces, unwashed salad, contaminated water - 0157 strain produces Shiga toxin - Shiga toxin destroy RBCs and leads to haemolytic uraemia syndrome (HUS) - Abx increase HUS risk - avoid Abx in E. coli CAMPYLOBACTER JEJUNI: - most common bacterial cause worldwide - travellers diarrhoea - raw / undercooked poultry, untreated water, unpasteurised milk - incubate 2-5, Sx resolve after 3-6days - cramps, diarrhoea maybe with blood, vomit, fever - Abx if bacteria identified or risks eg HIV or heart failure - Abx: azithromycin or ciprofloxacin SHIGELLA: - faeces in drinking water or swimming pool or food - 1-2 days incubation, Sx resolve in a week - bloody diarrhoea, cramps and fever - Shiga toxin and HUS - severe then use Abx azithromycin or ciprofloxacin SALMONELLA: - raw eggs or poultry, or reptile infected food - incubation 12hr to 3days and Sx resolves in 1week - watery diarrhoea maybe mucous or blood - abx only in severe and guided by stool C+S BACILLUS CEREUS: - gram +ve rod - inadequately cooked food / not refrigerated eg rice - cereulide toxin; cramp and vomit within 5hours - watery diarrhoea within 8hrs - resolves within 24hrs - classic course so exam worthy YERSINIA ENTEROCOLITICA: - gram -ve bacillus - pigs, so undercooked pork - urine or faeces of rats / rabbits - 4 to 7 days incubation - watery or bloody , fever, pain - lymphadenopathy - mesenteric lymphadenitis in older children (appears like appendicitis) STAPH AUREUS TOXIN: - enterotoxins on eggs, diary or meat - start within hours and settle within 12 to 24 - D+V, cramps, fever GIARDIASIS: - G. lamblia parasite in mammals - cysts from faecal oral transmission - chronic - stool microscopy - metronidazole

Question 29

Principles of gastroenteritis management?

Answer 29

- isolate and barrier nursing - oral fluid challenge every 10 mins and keep it down and not dehydrated then can go home - dioralyte ie ORS - dehydrated / cant keep fluid challenge down the IV fluids - avoid loperamide (antidiarrhoeal) and anti-emetics - abx only if at risk and ID on organism

Question 30

4 post gastroenteritis complications?

Answer 30

- lactose intolerance - IBS - reactive arthritis - Guillain-Barre syndrome