What is epidemeology?
The study of the patterns, causes and factors affecting the health and disease in a population.
What is a communicable disease?
An infectious disease that is able to be transferred from one organism to another.
What is a contagious disease?
An infectious, communicable disease that is able to be transferred from one organism to another with ease.
What is a zoonotic disease?
An infectious disease that is able to be transmitted directly between different species of animals, including human to animal and animal to human transmission.
What does the term incidence refer to?
The number of NEW cases in a given population. Can be expressed by incidence proportion.
What does the term morbidity refer to?
The rate of diseased people to non disease people as could be expressed by 2 per 1000.
What does the term mortality rate refer to?
The rate of deaths from a disease within a given population as could be expressed by 7 per 100 000.
What is a sporadic disease?
A disease that only occaisionally within a given population, seeming to pop up.
What is an endemic disease?
A disease that continually infects a given population, for example aids could be said to be endemic in Africa.
What is an epidemic?
Refers to the outbreak of a disease, showing a higher than normal rates in a given population.
What is a pandemic disease?
The outbreak of a disease, showing higher than normal rates on a global or international scale.
What are the components of the chain of infection?
- Source: The pathogen itself
- Reservoir: Where the pathogen is held in large numbers, it could be an organism, a river, a crop etc.
- Portal of exit: How it exits its reservoir or its host organism. Eg. sneezing, or perhaps it is carried from the soil on the bottom of shoes.
- Mode of transmission: Is it direct or indirect? Contact, droplet or airborne?
- Portal of entry: The way it gets into an organism. Inspiration, ingestion, animal bite etc.
- Susceptability of host: How easily a host can become infected. Does it relate to age, sex, vaccination status and so on.
What is a carrier?
A carrier is a person (or organism) that is carrying a pathogen, but is not suffering disease. They can pass the pathogen onto other people.
What is a passive carrier?
A carrier who never actually catches the disease.
What is an incubatory carrier?
A carrier who can transmit the disease while it is still in its incubatory form.
What is an active carrier?
A person who has fully recovered from the disease but is still a carrier.
What is a covalescent carrier?
A person who is still recovering from the disease and can infect other people.
What are 5 important animal reservoirs of disease?
- Dogs and Cats
What are 5 important non-living reservoirs of disease?
What are fomites?
Non living, inanimate objects that have become reservoirs of infection.
What are the 5 principle modes of transmission?
- Airborne - Carried in the air
- Droplet - Suspended in water droplets
- Contact - By direct contact between people
- Vehicular - By fomites
- Vector - By biting from animals, or by injection
What are 7 ways communicable diseases are most commonly transmitted?
- 1. Direct: Skin to skin
- 2. Direct: Mucous membrane to mucous membrane
- 3. Indirect: Airborne or droplets
- 4. Indirect: Contact with contaminated food, water or fecal material
- 5. Indirect: Arthropod vectors eg. mosquitos
- 6.Indirect: Contact with fomites
- 7. Indirect: Blood to blood product or parental injection.
What are healthcare associated infections (HAIs)?
Infections acquired while in hospital or another healthcare facility.
What are community acquired infections (CAIs)?
An infection acquired outside of a healthcare setting.
What is an iatrogenic infection?
One that is acquired through surgery or treatment.
What are the most common ways HAIs are transmitted.
- Contact - Doctor to patient, patient to patient, fomites.
- Droplet - From other patients, Doctors.
- Airborne - From other patients, Doctors.