Epidemiology Fundamentals

Study Notes

Epidemiology

Study of disease, focusing on factors that determine frequency, distribution, and determinants of diseases in human populations
Epidemiologists develop ways to prevent, control, or eradicate diseases in populations

Types of Diseases

Communicable disease: infectious disease that can be transmitted from one person to another
Contagious disease: communicable disease that is easily transmitted from person-to-person
Zoonotic disease: disease that humans acquire from animal sources

Disease Measures

Incidence: number of new cases of a disease in a defined population during a specific time period
Morbidity rate: number of new cases of a disease per a specifically defined population (usually per 1,000, 10,000, or 100,000) during a specified time period
Prevalence: number of cases of a disease existing in a given population during a specific time period
- Period prevalence: number of cases during a specific time period (e.g., during the year 2006)
- Point prevalence: number of cases at a particular moment in time
Mortality rate: ratio of number of people who died of a particular disease during a specified time period per a specified population

Disease Occurrence

Sporadic disease: disease that occurs only occasionally within a particular geographic area (e.g., tetanus)
Endemic disease: disease that is always present within the population of a particular geographic area (e.g., gonorrhea)
Epidemic disease: greater than usual number of cases of a disease in a particular region, usually within a short period of time (e.g., Legionnaires disease epidemic of 1976)
Pandemic: disease that is occurring in epidemic proportions in many countries simultaneously (e.g., Influenza, HIV/AIDS, Tuberculosis, Malaria)

Biological Warfare and Bioterrorism

Biological warfare (BW) agents: use of microorganisms in times of war
Bioterrorism agents: use of microorganisms to create fear, chaos, illness, and death
Four most likely potential agents: Bacillus anthracis, Clostridium botulinum, Smallpox virus (Variola major), and Yersinia pestis

Water and Sewage Treatment

Rural and suburban areas: septic tanks
Urban areas: wastewater treatment plants
Primary sewage treatment: physical process
Secondary sewage treatment: biological process
Tertiary sewage treatment: additional treatment steps
Chlorination: bleaching and disinfection
Filtration: using fine sand and charcoal
Distillation: purification process
Major steps in water treatment:
- Sedimentation (settling)
- Coagulation (flocculation)
- Filtration
- Chlorination

Description

Learn the basics of epidemiology, including the study of disease frequency, distribution, and determinants in human populations. Discover how epidemiologists develop ways to prevent, control, or eradicate diseases.