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During the COVID-19 outbreak, epidemiologists worked hard to identify the novel disease, determine how it spread and research ways to mitigate the harsh impacts of a pandemic. Infectious diseases aren’t the only health conditions that these professionals study. Others include chronic, environmental and mental health conditions.
To learn more, check out the infographic below, created by Augusta University Online’s Master of Public Health program.
What Is Epidemiology?
Epidemiology is the science of investigating the causes and transmission of diseases. Epidemiologists study what causes diseases and how diseases spread in order to use this information to protect people from illnesses and improve their overall health.
Epidemiologists collect, analyze and interpret public health data to understand the spread of diseases, including infectious diseases and chronic diseases. This is known as public health surveillance.
John Snow, known as the father of modern epidemiology, investigated London’s 1854 cholera outbreak. By mapping cases and tracking its spread, Snow concluded that cholera was a waterborne disease. Snow’s groundbreaking and lifesaving research changed public health knowledge before the germ theory of disease had been established.
5 Types of Epidemiology
As public health experts, epidemiologists specialize in infectious diseases and chronic diseases. But these are only two of several specializations in epidemiology.
Infectious Disease Epidemiology
Infectious disease epidemiology is the study of illnesses caused by germs, including bacteria and viruses. Americans make about 23 million doctor’s visits annually because of infections, according to the National Institutes of Health.
The goals of infectious disease epidemiology are to prevent and control infections. This type of epidemiology also aims to prevent diseases through public education. Common methods used in infectious disease epidemiology are public health surveillance, infectious disease reporting, immunizations and vaccines.
Chronic Disease Epidemiology
Chronic disease epidemiology is the study of chronic illnesses, which are those that continue or occur repeatedly. Heart disease, cancer, diabetes and hypertension are chronic diseases. In 2018, it was estimated that around 129 million Americans have at least one major chronic disease, according to the Centers for Disease Control and Prevention.
The aims of chronic disease epidemiology include identifying the social determinants of chronic diseases, reducing health disparities and improving health outcomes. Chronic disease epidemiology methods include public health surveillance, observational data analysis and public health education.
Environmental Epidemiology
Environmental epidemiology is the study of how the environment impacts people’s health and the spread of diseases. Roughly 24 percent of global deaths are estimated to be linked to the environment, according to the World Health Organization.
This type of epidemiology aims to identify environmental risk factors and limit the harm caused by environmental contaminants. Environmental epidemiologists use methods such as public health surveillance, environmental exposure data analysis and cluster outbreak investigations.
Psychiatric Epidemiology
Psychiatric epidemiology is the study of the distribution and determinants of mental disorders. Half of the people around the world will experience a mental health disorder in their lifetime, according to a study by the Harvard Medical School and the University of Queensland.
The goals of psychiatric epidemiology include preventing mental health conditions and improving people’s health and well-being. Psychiatric epidemiology methods include clinical psychological research and mental health data analysis.
Neuroepidemiology
Neuroepidemiology is the study of diseases that impact the central nervous system. Over 3 billion people globally had a neurological condition in 2021, according to the World Health Organization.
The goals of neuroepidemiology include identifying the causes of nervous system disorders and preventing and finding treatments for neurological diseases. The methods used in neuroepidemiology include observational studies of neurologic disorders, experimental research on medications and interventions, and diagnostic prediction research.
Types of Epidemiology Studies
Epidemiology studies fall into two broad categories: descriptive studies and analytic studies.
Descriptive Epidemiology Studies
Descriptive epidemiology studies examine the patterns of diseases, investigate which locations and populations are impacted by them and generate hypotheses. These studies are often used to allocate public health resources. In the 1980s, descriptive studies of HIV identified high risk groups, creating a hypothesis about the cause of AIDS.
Types of descriptive studies include case reports, case series and incident studies.
Analytic Epidemiology Studies
Analytic epidemiology studies identify the causes and effects of diseases. They also analyze the distribution of diseases and determine the links between exposures and outcomes. After a descriptive study identified an outbreak of a foodborne illness, for example, an analytic study compared an exposed and a nonexposed group to identify the source.
Analytic studies can be experimental studies or observational studies.
In experimental studies, researchers conduct trials to gain clinical insights. These experiments can determine the most effective public health responses. For example, public health researchers might study the impact of a public health education campaign on a community’s health and wellness. Clinical and community trials are examples of experimental studies.
In observational studies, researchers analyze patterns of exposure to understand diseases. For example, researchers might compare influenza rates in populations with different immunization levels. Long-term observational studies can take decades to complete. Types of observational studies include cohort, case control, cross-sectional and ecological studies.
The Benefits of Epidemiology
Epidemiologists specialize in many areas, such as chronic diseases, environmental risk factors and mental health. By using descriptive and analytic approaches, these epidemiologists help improve people’s health and wellness.
Sources
Alabama College of Osteopathic Medicine Library, Public Health: Epidemiology
American Academy of Neurology, Career Paths In Neuroepidemiology
The British Medical Journal, “What Is Epidemiology?”
The Cambridge Handbook of Research Methods in Clinical Psychology, “Psychiatric Epidemiology Methods”
Centers for Disease Control and Prevention, “Analytic Epidemiology”
Centers for Disease Control and Prevention, “Chronic Disease Prevalence in the US: Sociodemographic and Geographic Variations by Zip Code Tabulation Area”
Centers for Disease Control and Prevention, State Chronic Disease Epidemiology Assignee Program
Cureus, “John Snow: The Pioneer of Modern Epidemiology and Anesthesia”
Delaware Health and Social Services, Office of Infectious Disease Epidemiology
ENeurologicalSci, “Neuroepidemiology: Basic Concepts and Population Surveys”
Gideon, “What Is Epidemiology?”
Harvard Medical School, “Half of World’s Population Will Experience a Mental Health Disorder”
Michigan Department of Health and Human Services, Chronic Disease Epidemiology
Minnesota Department of Health, About the Infectious Disease Epidemiology, Prevention and Control (IDEPC) Division
National Institutes of Health, Infectious Diseases
Northwest Center for Public Health Practice, “Study Types in Epidemiology”
Tasman’s Psychiatry, “Psychiatric Epidemiology”
Viruses, “Epidemiology and Transmission Dynamics of Infectious Diseases and Control Measures”
Washington State Department of Health, Environmental Epidemiology Section
World Health Organization, Environmental Health
World Health Organization, “Over 1 in 3 People Affected by Neurological Conditions, the Leading Cause of Illness and Disability Worldwide”
World Health Organization, Public Health and Environment
U.S. Bureau of Labor Statistics, Epidemiologists
