W4 L4 Epidemiology Flashcards
Define epidemiology
The study of the occurrence, spread and control of disease
Define communicable disease
Any infectious disease that can be transmitted from one person to another
Define contagious disease
An infectious disease that is easily transmitted from one person to another
Define zoonotic disease
An infectious disease that humans catch from animals
Give examples of animals that can carry zoonotic disease
- Birds
- rodents
- cats and dogs
- mosquitos
- cattle
Define incidence
Number of new cases within a population at a certain time
Define morbidity rate
The number of new cases of disease over a defined period of time specifically defined number of individuals (sickness)
Define mortality
The ratio of the number of people who have died from a particular disease over a specific time period in a specific region.
Define endemic
a disease that is always present
Define epidemic
A disease that is occuring in great than usual numbers within a specific geographical region.
Define pandemic
A disease that is occurring in epidemic proportions in many countries
What are the components in the chain of infection?
- Infectious agent
- Reservoir
- Portal of exit
- Mode of transmission
- Portal of entry
- Susceptible Host
Define reservoir
Places in the enviroment where the pathogen lives
Define infectious agent
Pathogen that causes disease
Define Portal of exit
They way which infectious agent leaves the reservoir
Define Portal of entry
The way the infectious agent can enter a new host
Define susceptible host
Can be any person
Describe variants of potential carriers
Humans, animals, soil, water, fomites, food
Are human most likely to spread disease to another human?
Yes
Define carrier
A person who is infected with a particular pathogen (not causing problem)
Define Passive Carrier
A person who carries a disease causing pathogen (without having had the disease)
Define convalescent carrier
A person who can transmit a particular pathogen while recovering from an infectious disease.
Define Active Carrier
A person who has completely recovered from a particular disease but continues to harbor the disease-causing pathogen indefinitely
List 5 principle modes of infectious disease transmission
- Contact
- Airborne
- Vector
- Droplets
- Vehicular
List common ways the communicable diseases are transmitted between humans
- Direct skin-skin contact
- Direct via mucous-to-mucous membrane
- Indirect - airborne coughing sneezing
- Indirect through contaminated water
- Indirect via fomites
- Indirect via contact with contaminated blood
Give examples of what can be used to break the chain of infection
- Diagnosis and treatment
- Cleaning
- Hand hygiene
- Isolation
- PPE
- Immunisations
Define healthcare associated-infections
Infections that are acquired within the healthcare facility
Define community associated infections
Infections that are acquired outside a healthcare facility
