Diarrhoea Flashcards
What are the bacteria that are sought by routine culture of stools from patients with diarrhoea in the UK?
1) Campylobacter
2) Salmonella enterica
3) E. coli O157
4) Shigella
What are some of the non-routine bacteria that can cause diarrhoea?
1) Staph aureus
2) Bacillus cereus
3) Clostridium perfringens
What are the commonly detected parasites in stool specimens in the UK?
1) Giardia Lamblia
2) Cryptospiridium Parvum
3) Entamoeba Histolytica
What are the commonly detected viruses that cause diarrhoea?
1) Norovirus
What is the definition of gasto-enteritis?
3 or more loose stools/day
What is the definition of diarrhoea?
Fluidity and frequency of bowel movements
What is the definition of dysentery?
Inflammation of the large bowel, including bloody stools
What is the most common food borne pathogen?
Campylobacter
What pathogen causes the most hospital admissions?
Salmonella
What measures are used to prevent the spread of enteric infection?
1 - Hygiene
2- Stomach acidity
3- Normal gut flora
4 - Immunity
What are the mechanisms of attachment via which infecting organisms can produce diarrhoea?
1 - Receptors on the gut mucosa
2- Gut mucosa directly
What is an example of a bacteria which uses the attachment process to cause diarrhoea?
E. Coli
What are the mechanisms of mucosal invasion which can produce diarrhoea?
1- Organism penetrates intestinal mucosa
2- Entry of infecting organism results in production of ‘invasins’
3- More bacteria to enter and produce symptoms of dysentry
What is an example of an infectious bacteria which acts via mucosal invasion to produce diarrhoea?
1 - Shigella
2 - Campylobacter
3 - E.Coli
What are the mechanisms of toxin production which can produce diarrhoea?
Enterotoxins: - Toxins produced by bacteria that adher to intestinal epithelium, which produce excessive fluid secretion into the bowel lumen - This leads to watery diarrhoea without physically damaging the mucosa
Cholera: - Increases cAMP levels and Cl secretion
What are the important components of history taking when dealing with patients with gastro-enteritis?
1 - How long have they had symptoms for, i.e. > 2 weeks means it’s not likely to be gastro-enteritis
2 - Have they been exposed to increased risk of food poisoning? e.g. foreign travel, dietary risk or contact risk
3 - What is the appearance of their stool?.
How is hydration assessed in a patient with gastro-enteritis?
1 - Skin Turgor
2 - BP
3 - Pulse
How is fluid replacement managed in a dehydrated patient?
- Use rehydration salts which contain a mixture of salts and sugars
- Rehydration can be performed orally or IV
What lab tests are performed for patients with gastro-enteritis?
1 - Stool and Blood culture (perform 3 to ensure infection cleared)
2 - Assess renal function
3 - FBC
4 - Abdominal X-ray
When should anti-bacterials be used in managing gastro-enteritis?
Antibiotics Indications:
- Immuno-compromised patients
- Valvular heart disease
- Diabetics
- Septic patients with invasive infection
- Chronic illness
What are the complications of gastro-enteritis?
1 - Haemolytic Uraemic Syndrome (E.Coli O157)
2 - Irritable bowel syndrome (salmonella)
3 - Guillian-Barre syndrome (campylobacter)
4 - Reactive arthritis
What is Haemolytic Uraemic Syndrome?
1 - Caused by E.Coli O157 shiga toxin getting into blood stream
2 - Renal failure, thrombocytopeania and haemolytic anaemia.
3 - Most common in exteremes of age (very young or very old) and immuno compromissed patients.
