(P) Lesson 2: Epidemiology Flashcards
The study of disease, injury, and death
Epidemiology
“The study of the distribution and determinants of health-related states and events in specified populations” whose definition does this belong to?
CDC
“The study of the distribution and determinants of health-related states or events and the application of this study to control health problems” whose definition does this belong to?
WHO
Refers to descriptive epidemiology (when, where, and who)
Distribution
Refers to incidence, prevalence, and mortality rates
Frequency
Refers to time, place, and person
Pattern
Refers to analytic epidemiology; deals with causes, risk factors, and modes of transmission (why and how)
Determinants
Refers to the agents
Causes
Refers to exposure to the agents
Risk Factor
Veni, Vidi, Vici
”I came, I saw, I conquered”
Discovered the theory of the four body humors produced within the body
Hippocrates
Discovered the “seeds of disease” and named “syphilis” in a poem
Girolamo Fracastoro
Stated that disease is called as an external thing referred to as an “ens” which could attack any organ of the body
Paracelsus and JB van Helmont
Person first to demonstrate procedures on microorganisms
Antoni Van Leeuwenhoek
Theory coined by Louis Pasteur; said that germs can causes diseases and developed a vaccine and treatment for anthrax and rabies
Germ Theory
Refers to how one germ can cause one type of disease
Biological Specificity
His postulates included:
- perfected growing pure bacterial colonies
- developed autoclaves
- introduced photography for what he had seen in his microscope
- identified agents that caused diseases such as tuberculosis and cholera in 1884
Robert Koch
He developed the “antiseptic” surgery which developed into “aseptic” surgery which he used carbolic acid dressings to disinfect surgical wounds
Joseph Lister
He studied cholera and concluded that it was not transmitted through miasma but through contaminated water
John Snow
He discovered the nature of viruses and their relationship to cells in the body
Martinus Beijerinck
- Delved into the fields of microscopy, tissue staining, embryology, chemotherapy, and immunology
- Developed the theory of the chemical nature of antigens and antibodies (lock and key)
Paul Ehrlich
He developed a polio vaccine using a weaker strain of the virus
Albert Sabin
He coined the term “prion” and explained how these misfolded proteins could cause disease
Stanley Prusiner
He worked on the retrovirus for HIV
Francoise Barre-Sinoussi
A concept in epidemiology referring to differences in disease and injury occurrence for different populations
Population and Comparison
A concept of disease occurrence which refers to the epidemiological triad or triangle
Causation
The epidemiological triangle consists of what 3 factors?
Agent, Environment, and Host
Widely used method which describes the basic epidemiology of a disease; data is collated by time, place, and person
Descriptive
Time trend that describes the occurrence of a disease over a prolonged period of time (can take up to years)
Secular
Time trend that indicates change in the antigenic characteristics of the disease agent (if it can occur once, it can occur again in the future)
Periodic
Diseases that occur more frequently depending on what time of year it is
Seasonal
Refers to sudden increase in occurrence due to prevalent factors
Epidemic occurrence of disease
Refers to level of a disease that signals the start and end of the season
Seasonal Threshold
The week in which positivity rate was above the weekly average for the year and which has continued for 3 consecutive weeks
Start or Onset of Outbreak
The first week where the positive rate was below the weekly average which continued for 3 consecutive weeks
End of Outbreak
Refers to level above which the disease activity was higher than most years
Alert Threshold
A method that analyzes disease determinants for possible causal relationships
Analytical
Method which starts with the disease and retrospectively investigates the cause
Case Control/Case Comparison Method
Refers to the gathering of individuals with the disease in a case control method
Case group
Refers to the gathering of individuals similar to the case group but do not carry the disease
Comparison (control) group
This method prospectively studies two populations
Cohort Method
This population had contact with suspected causal factor under study
Population 1
This is a similar group that had no contact with the causal factor under a cohort study
Population 2
This method determines the relationship between a disease and present variables
Cross-Sectional Method
Method in which one or more selected factors are manipulated and the effects of manipulation will either confirm or disprove the hypothesis of the drug effectivity
Experimental 1
Refers to a proportion of people who died among all the individuals diagnosed with the same disease over a period of time
Case Fatality Rate/Fatality Risk or Ratio
This measure of mortality involves the total no. of deaths during a given time interval/mid-interval population (1,000 or 100,000)
Crude Death Rate
This measure of mortality involves the no. of deaths assigned to a specific cause during a given time interval/mid-interval population (100,000)
Cause-specific Death Rate
This measure of mortality involves the no. of deaths assigned to a specific cause during a given time interval/total no. of deaths from all causes during the same time (100 or 1,000)
Proportionate Mortality
This measure of mortality involves the no. of deaths assigned to a specific cause during a given time interval/no. of new cases of the same disease reported on the same time (100)
Death-to-Case Ratio
This measure of mortality involves the no. of deaths among children less than 28 days in age during a given time interval/no. of live births during the same time (1,000)
Neonatal Mortality Rate
This measure of mortality involves the no. of deaths among children less than 1 year old during a given time interval/no. of live births during the same time (1,000)
Infant Mortality Rate
Refers to living organisms or non-living sites (soil or water) for pathogen to grow
Reservoirs
Refers to individuals capable of transmitting pathogens without displaying symptoms
Carrier
Type of carrier that harbors and transmits the pathogen but is not infected
Passive
Type of carrier that is infected and can transmit the pathogen (symptomatic or asymptomatic)
Active
Type of transmission that is person-to-person (touching, intercourse, or droplets)
Direct
Type of transmission that involves inanimate objects called “fomites”
Indirect
Type of transmission where pathogens travel through water, food, air, etc.
Vehicle Transmission
Type of vector transmission which harbors the pathogen but is not infected (e.g. fly)
Mechanical
Type of vector transmission that is infected and can transmit the pathogen (e.g. flea)
Biological
Refers to occurrence of new cases of disease or injury in a population over a specified period of time
Incidence
Defined as a departure from a state of well-being as it encompasses disease, injury, and disability
Morbidity Frequency Measures
Measure of morbidity that involves the no. of new cases of disease during a specified time/population at the start of time interval
Incidence Proportion (Attack Rate/Risk)
Measure of morbidity that involves the no. of new cases among contacts/total no. of contacts
Secondary Attack Rate
Measure of morbidity that involves the no. of new cases of disease during a specified time/summed person to years of observation or average population during specified time
Incidence Rate (Person-Time Rate)
Measure of morbidity that involves the no. of current cases (new and existing) at a specified point/population at the same specified time
Point Prevalence
Measure of morbidity that involves the no. of current cases (new and existing) over a period of time/average or mid-interval population
Period Prevalence
Refers to relative magnitude of 2 quantities or a comparison of any 2 values
Ratio
Refers to comparison of a part to a whole; type of ratio where the numerator is included in the denominator
Proportion
A measure of frequency with which an event occurs in a defined population over a specified period of time
Rates
