BIOL 437 Week Two Part 1 Flashcards
disease
-an interpretation or disorder of body functions, systems or organs
diseases arise from
- infectious agents (pathogens)
- inherent weaknesses
- environmental stresses
environment
- all that is external to the human host
- physical, social, biological, cultural
‘random’ occurrence of disease
-do not occur randomly
>some individuals are more at risk as risk factors are not randomly distributed in the population
epidemiologic triad/triangle
- Agent
- Susceptible host
- Environment (now has a major influence)
* simplest model of disease causation
agent
- infectious micro-organism/pathogen
- toxins, physical forces
chronic diseases with multiple causes
- triad model does not work well
eg. CVD, cancer
infectious microorganisms/pathogen
- virus, parasite, bacterium
- necessary, but not necessarily sufficient alone (ex. dose, pathogenicity)
host
-human or animal who can get the disease
risk factors influences
- exposure
- susceptibility
- response to agent
examples of risk factors
- behaviours
- hygiene
- psychological makeup
- medications
- gender
- age
- genetics
- nutrition
- immune status
- comorbidity
environment
-factors affecting the agent and the opportunity for exposure
examples of environment
- geology
- climate
- socioeconomic factors
- biologic factors (insect vectors)
socioeconomic factors
- crowding
- sanitation
- access to health care
primary focus in epidemiology
- identifying the causes of disease
- identify mechanisms by which disease spread
etiology
-science and study of the causes of disease and their mode of operation
communicability
-ability of a disease to be transmitted from one person to another or to spread through the population
classify acute and chronic disease according to
- infectivity
- communicability
communicable disease
-when an infectious disease is contagious or capable of being communicated or transmitted
examples of communicable diseases
- HIV/AIDS
- cholera
- influenza
- cryptosporidiosis
vertical transmission
-transmission from an individual to its offspring through sperm, placenta, milk or vaginal
horizontal transmission
-transmission of infectious agents from an infected individual to a susceptible peer
pathogens
-organisms or substances such as prions, bacteria, viruses, fungi, or parasites that are capable of producing diseases
invasiveness
-the ability to get into a susceptible host and cause diseases