PMB: Epidemiology L2 Flashcards
What is epidemiology?
The study and Analysis of the distripution, patterns and determinants of disease in defined populations. It includes:
- Nature of the infection
- Distribution
- Causation
- Prevention
- Mode of transfer
- Control
What does epidemiology entail?
- Studying the vector spreading/ carrying the disease
- Monitoring the host (patient in medicine)
- Studying disease reseviors
- Monitoring ofinfectous agents
- Surveillance of notifiable disease
What causes the spread of an epidemic?
- Natural international spread of diseases (e.g. migratory species i.e. sparrow)
- Global travel
- International food distribution
Why is it important to study epidemiology?
- Knowledge of how the disease spreads can either: half the rate of it spreading i.e. buy time OR prevent further spread of the disease
- Knowledge of the problem can determine the innervation e.g. impose controlls in regions of a country OR across national borders.
- I.e in Austrailia they prevent movement between states to prevent disease spreading in crops or they built a physical barrier across the length of the country to prevent dingo attacking sheep
What is an example of a potential control/ barrier to prevent spread of diseases between coutries/ regions/ areas?
- Geographical isolation - Physical barriers such as mountains, desserts and being an island can act as a good control to prevent spread of disease
What does the effectiveness of a barrier depend on?
- The mode of movement of the disease - For example if a disease spreads by air or sea there is potentially a problem for the disease spreading from denmark to sweeded. However it is spreads by land, due to the round about distance it would have to travel there wouldn’t be a problem
- The ability to enforce the barrier - e.g. effectiveness of border control to limit infection route
Discuss the Ebola outbreak in regards too:
- Nature of disease
- Countries infected
- Possible promblems
- Death rate
- Nature:
- Virus
- Animals are reseviors
- Can pass from human to human by transfer of blood or other secretions
- Humans infected by animals (bats)
- infected:
- Outbreak originated in Guinea
- Spread to neighbouring African coutnries e.g. Sierra Leone and Bombali
- Not everyone obeys restrictions e.g. man fled fom Aberdeen in Sierra Leone leading to possible spread and outbreaks else where (second generation)
- Some people live, others die. Aprov 50% fatality rate
What are types of outbreaks?
- Person - to - person
- Slow outbreaks as takes time to occur and outbreaks increase
- This also means it can take a while to subside
- e.g. Dysentery
- Explosvie outbreaks
- Occur in a relatively short time period
- Large number of people effected very quickkly
- e.g. cholera from contaminated water
- Not always as simple s fast/ slow. Some may start out as rapid explosive, then become more of a person-to-person spread, with the rate of spread slowing but the disease persiting in the population for sometime
When and what diseases need to be reported?
- If it is a condition that is considered to be sufficently harmful
- Veterinary diseases also need to be noted - may infect humans
- Plant diseases need to be noted - but notas relevant to humasn
What are questions that need to be addressed in the event of a new outbreak?
WHO was infected – deals with demography of outbreak
WHEN did infection occur – deals with incubation period
HOW did infection occur – deals with source and route
WHY did it occur – e.g. reheating of food, etc.
WHERE did it occur – e.g. hospital, restaurant, etc.
OTHER common factors – e.g. holiday destination, flight, etc.
Who is involved in data analysis and what can be done from this informatino?
Health Protection Agency (HPA)
World Health Organisation (WHO)
Health Protection Scotland (HPS)
Information can be used to predict when outbreaks will ocur and ppredict how outbreaks spread
how can outbreaks be controlled?
- Can the source be identified – and dealt with
- Airborne infections, contaminated food / water, etc
- Do affected individuals need to be isolated
- Is a programme of vaccination needed
- Is a public health campaign required
