GI infections & diseases Flashcards
Case based PH management
(what to do when a case of a disease is reported)
- find out symptoms (make sure fits diagnosis)
- when did symptoms start
- place (of residence, travel, contact with someone with disease, been to a location where lots of people congregate (depends on how much exposure needed), shared cooking/food/utensils, sexual partners, school (if relevant),
- travel on plane (depends on condition - laminar flow in planes)
- vaccination history
- Risk assessment (how social are they etc.)
- Contacts: depends on incubation period (1 week for meningitis). Give high risk contacts chemoprophylaxis (for meningitis - coverage up to 28 days from contact)
What is the objective of a public health history
where did pt get disease from and who might they have given it to
Identify risk settings & high risk groups
What PH action to take following risk assessment
Initiate action for confirmed and probable cases (usually not for possible cases)
there is a difference between individual level case management and population level case management (therefore if high numbers of cases or if it is endemic response might be different - may have to cut corners)
How are GI infections defined
transmission route (faecal-oral) not presentation/symptoms (any infection whos source is in the GI tract)
Most common (globally) GI infections
Ecoli
Salmonella
Cholera
Shigella
Typhoid
Travellers Diarrhoea
Most common (UK) GI infections
Viral: norovirus (effects elderly), rotavirus (effects young) (rotavirus decreasing due to vaccine)
Bacterial: Campylobacter, salmonella
Shiga toxin
Dangerous
Produced by STEC (Shiga toxin producing E Coli (most common = E.coli0157) & shigella
Travels throughout body
Can cause haemolysis and kidney failure (HUS: Haemolytic Uraemic Syndrome)
Parasites that can cause GI infection
Cryptosporidium
Giardia - can cause long term malnutrition
Issues with diarrhoea surveillance
Cases reported = tip of the iceberg
Not all go to GP, not all that go to GP get tested
Often norovirus clears within 2 days whereas campylobacter lasts longer (2 weeks) - so numbers appear higher
What is the epidemiological triangle
Host (age, sex, race, genetics, previous disease, immune status, religion, customs, occupation, marital status, family background)
Environment (temperature, humidity, altitude, crowding, housing, neighborhood, water, milk, food, radiation, pollution, noise)
Agent (biologic (bacteria, viruses), chemical (poison, alcohol, smoke), physical (trauma, radiation, fire), nutritional (lack, excess)
Key aspects of agent in epidemiology triangle
An organisms transmissibility determines likelihood of spread
An organisms pathogenicity determines its likelihood of causing severe illness
Key aspects of host in epidemiology triangle
Susceptibility - likelihood of acquiring an organism & how severe the disease is likely to be
GI Risk groups
Group A: people who can’t practice good hygiene (mental illness, elderly, no WASH)
Group B: children before their 6th birthday party & attend childrens groups
Group C: food handlers
Group D: health and social care workers
(groups C&D generally won’t get very ill but risk transmitting to lots of people)
(Group B: concerning as can get it easily, pass it on easily and can get complications)
Standard diarrhoea exclusion advice
stay away from work/school for 48 hours after the diarrhoea stops (as when diarrhoea stops not all bacteria gone)
Diarrhoea exclusion in Risk Groups
need to test negative before go back to work – people who deal with food, work with immunocompromised etc. generally all healthcare workers and social workers
