What is epidemiology?

Epidemiology is the method used to find the causes of health outcomes and diseases in populations. In epidemiology, the patient is the community and individuals are viewed collectively. By definition, epidemiology is the study (scientific, systematic, and data-drive) of the distribution (frequency, pattern) and determinants causes, risk-factors) of health-related states and events (not just diseases) in specified populations (neighborhood, school, city, state, country, global). It is also the application of this study to the control of health problems.

Who are epidemiologists?

When diseases outbreaks or other threats emerge, epidemiologists are on scene to investigate. Often called “Disease Detectives”, epidemiologists search for the cause of disease, identify people who are at risk, determine how to control or stop the spread or prevent it from happening again.

Like investigators at the scene of a crime, disease detectives begin by looking for clues. They systematically gather infor-mation, asking questions such as:

Who is sick?
What are their symptoms?
When did they get sick?
Where could they have been exposed?

Using statistical analysis, epidemiologist study answers to these questions to find out how particular health problems were introduced. Disease detectives use what they learn during the investigation and make recommendations to control the spread or prevent a future occurrence.  

Public health problems or events that epidemiologist may investigate: 

Environmental exposures
  • Lead and heavy metals
  • Air pollutants and other asthma triggers
Infectious Disease 
  • Foodborne illness
  • Influenza and pneumonia
  • Increased homicides in a community
  • National surge in domestic violence 
Non-Infectious Disease 
  • Localized or widespread rise in a particular type of cancer
  • Increase in a major birth defect 
Natural Disasters 
  • Hurricanes Katrina and Rita (2005)
  • Haiti earthquake (2010) 
  • World Trade Center (2001)
  • Anthrax release (2001)  

Source: Centers for Disease Control and Prevention – Teacher roadmap (Updated: June 17, 2017) 

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