Lecture 23 - Diarrhoea and Acute GI Illness

Question 1

Dysentry?

Answer 1

blood in diarrhoea

Question 2

Severe diarrhoea?

Answer 2

6x + per day

Question 3

Differences in microbial causative agents?

Answer 3

viruses then bacteria then protozoa in timely onset of symptoms, diarrhoea definite in bacterial and protozoa infection, vomiting definite in viral infection, fever in virus, abdominal pain in b and p, antibiotics sometimes useful for protozoa

Question 4

Viral causes?

Answer 4

norovirus, rotovirus - watery diarrhoea, ab cramps, muscle pain, low fever, headache

Question 5

Treating viral?

Answer 5

Let run its course, symptom treatment with rehydration, be aware of outbreaks, norovirus vaccine available

Question 6

Bacterial pathophysiology?

Answer 6

colonisation of intestines and production of toxins, invasion of intestinal tissue; food poisoning is toxins produced in food with no infection

Question 7

Bacterial causes - toxin release?

Answer 7

STEC/VTEC, shigell dysenteriae - dysentery common

Question 8

Bacterial causes - invasion?

Answer 8

campylobacter, salmonella, e. coli - ab cramp common, possible blood in stoll

Question 9

Food poisoning?

Answer 9

S. aureus, bacillus cereus - vomiting within 2-7h, clear in 1-2 days, most likely from leftovers

Question 10

Protozoa?

Answer 10

giardia, cryptosporidium - symptoms lasts for weeks, foul diarrhoea, ab cramps, self-limitng but antibiotics possibly necessary, severe progression if immune compromised, disinfectant resistant

Question 11

Sources of infection?

Answer 11

animal and human faeces, animals, infected people, contaminate food and water

Question 12

Preventative measures - food?

Answer 12

regulated slaughter, sharer farming practice, cooking, storage, hygeine

Question 13

Preventative measures - drink?

Answer 13

smarter farming, stricter water supply, sewerage systems

Question 14

Risk factors?

Answer 14

retail food, certain foods, farm animals, untreated water, faecal contact, symptomatic people, recreational water

Question 15

Bacteria, diagnostic tests?

Answer 15

severe diarrhaoea (STEC if bloody), stool sample, toxin test (microscopy useless as faecal bacteria presence normal)

Question 16

MacConkey agar with lactose?

Answer 16

E. Coli positive, salmonella negative

Question 17

MacConkey with Sorbitol?

Answer 17

E. Coli positive, STEC negative

Question 18

XLD?

Answer 18

Salmonella positive

Question 19

Diagnosing viral cause?

Answer 19

outbreak, antibody or PCR based test

Question 20

Diagnosing protozoa?

Answer 20

4+ weeks of diarrhoea without bacteria, antigen test

Question 21

Compliations?

Answer 21

dehydration, bacteraemia, haemolytic uremic syndrome, Guillain Barre syndrome, reactive arthritis

Question 22

Symptomatic treatment?

Answer 22

mixture of clean water, salt and sugar, anti-motility drugs (maybe)