Diarrhoea and Acute Gastrointestinal Illness Flashcards
What are the signs and symptoms for acute gastrointestinal illness?
- Vomiting
- intoxifications
- nausea
- Diarrhoea
- acute
- watery
- bloody (dysentery)
- Severe ( 6x+ a day)
- Abdominal pain (especially if invasive, think pain relief)
- Fever
Draw out the table ofmain causative agents for diarrhoea including the
Onset
diarrhoea
vomiting
fever/pain
rehydration?
Antibiotics?
What are we talking about when it’s a viral agent? what’s the main symptom?
- Norovirus ; rotavirus
- Main symptom: nausea and vomiting
- watery diarrhoea, abdo cramps, muscle ach, low grade fever, headache also
How do viruses cause poops?
- Colonisation of the small intestine
- norovirus, +ve strand ss RNA
- Rotavirus, dsRNA, produces enterotoxin stimulating Cl- secretion
- Generally self limiting, over in 48hrs
- effective rotavirus vaccines available
- supportive treatment with effective rehydration is sufficient
- Be aware of outbreaks and potential for outbreaks
How do Bacterial agents cause poops?
- Colonisation of intestines and the production of of toxins
- clostridium difficile (nosocomial diarrhoea)
- Shida (or vero) toxin-prodiucing escherichia coli
- Shigella dysenteriae
- Enterotoxigneic Escherichia coli
- Colonisation of intestines invasion of intestinal tissue
- Campylobacter jejuni
- non-tympoid salmonella
- Yersinia enterocolitica
- Enteroinvasive escherichia coli
- Toxin produced in food and ingested, no infection. Food poisoning.
- Staphylococcous aureus
- clostridium perfrinfens
- Vomiting likely within 2-7 hr of consumption
- Symptoms cleared within 1-2 days
- Identification most likely from remaining food
How do protozoan cause poops?
- Food/ water*** contaminated by human/animal faeces
- @risk trampers, farmers, pet owners, kids
- incubation perior 1+ weeks
- Symptoms can last 4-6weeks
- colonisation of SI
- DIarrhoea, flatulence foulsmelling stools, abdo cramps
- mainly self limiting but antimicrobials may be neccessary
- Severe in immunocompromised individuals
- Cysts are resistant to disinfectants (eg; chlorine, so boil your water)
Diarrhoeal disease in developing countries?
- The 2nd leading cause of death in kids under five in developing countries
- kills 1.5 million kids every year (120,000 due to cholera)
- 2billion cases worldwide a year (~5million cholera)
- Affects kids and eldery
AGI is linked with outbreaks of disease. What is an outbreak?
Outbreak: 2 or more cases linked to a common source
- can be community-wide or person-to-person
- generally norovirus the #1 outbreak agent
The source and ROutes of Transmission of disease are?
Sources:
- Animal GI tract/faeces
- Huan GI tract/faeces
- animal
- infected people and carriers
- contaminated food
- contaminated water
ROT
- Faecal/oral route
- direct (food or water)
- indirect (cutlery)
What are the ways we block these routes of transmission?
- Slaughtering
- farming practise
- storage; fridge, tins
- cooking
- hygiene etc
The risk factos for AGI are?
- Consume food from retail premises
- consume at-risk produce (eg; soft cheese for Listeria)
- Contact with farm animal
- consume untreated water
- contact with faecal matter
- contact with symptomatic people
- contact with recreational water
- oversease travel within incubation period
- contact with sick animals
If someone has severe diarrhoea, you should do a ______?
Stool culture
- this will confirm the agent
- Also important to confirm resolution for people, especially food workers
- many require 3x negative test before can go back to work
- If poo is bloody, test for STEC; and look for it’s toxins over the agent
Why is microscopy limited?
Because there’s already a huge number of bacteria colonies in faeces
WHat are the stool culture methods?
SHeep blood agar: grows most pathogens
MacConkey Agar with lactose: mainly for E.coli
MacCOnkey agar with SOrbitol: Most E.coli femrent but STEC can’t
XLD: salmonella and Shigella
Campy plate: a large slection of AB’s that campylobacter are resistanct to but kill other bacterias as campylobacteria is particularly hard to diagnose!
How do we test for viruses/Protozoa?
- If an outbreak: test norovirus and rotavirus
- If 4+wks of diarrhoea, it’s not bacterial: test Giardia and cryptosporidium
- Stool testing: involves anitbody or PCR based test. Do an EIA for rotavirus
- Antigen test: do possible microscopy of ova etc
