Skip to content
Life & Health Sciences
Microbiology
Disease and Epidemiology

Disease and Epidemiology

A close-up of a red biohazard waste bin with a rectangular orange-red warning label showing the black biohazard trefoil symbol above the word BIOHAZARD, and a red plastic liner bag visible curling over the bin's rim.
Signs like this may seem self-explanatory today, but a few short centuries ago, people lacked a basic understanding of how diseases spread. Microbiology has greatly contributed to the field of epidemiology, which focuses on containing the spread of disease. (credit: modification of work by Tony Webster)

In the United States and other developed nations, public health is a key function of government. A healthy citizenry is more productive, content, and prosperous; high rates of death and disease, on the other hand, can severely hamper economic productivity and foster social and political instability. The burden of disease makes it difficult for citizens to work consistently, maintain employment, and accumulate wealth to better their lives and support a growing economy.

In this chapter, we will explore the intersections between microbiology and epidemiology, the science that underlies public health. Epidemiology studies how disease originates and spreads throughout a population, with the goal of preventing outbreaks and containing them when they do occur. Over the past two centuries, discoveries in epidemiology have led to public health policies that have transformed life in developed nations, leading to the eradication (or near eradication) of many diseases that were once causes of great human suffering and premature death. However, the work of epidemiologists is far from finished. Numerous diseases continue to plague humanity, and new diseases are always emerging. Moreover, in the developing world, lack of infrastructure continues to pose many challenges to efforts to contain disease.

Sections

  • The Language of Epidemiologists — prevalence versus incidence, sporadic, endemic, epidemic, and pandemic disease, Koch’s postulates and their modifications for determining the etiology of disease, and the relationship between epidemiology and public health.
  • Tracking Infectious Diseases — the research approaches of the pioneers of epidemiology, John Snow, Florence Nightingale, and Joseph Lister, and how descriptive, analytical, and experimental epidemiological studies determine the cause of morbidity and mortality.
  • Modes of Disease Transmission — the different types of disease reservoirs, contact, vector, and vehicle modes of transmission, important disease vectors, and the prevalence of healthcare-associated (nosocomial) infections.
  • Global Public Health — the entities involved in international public health and their activities, and the difference between emerging and reemerging infectious diseases.

This chapter is adapted from Microbiology, Chapter 16: Disease and Epidemiology by Nina Parker, Mark Schneegurt, Anh-Hue Thi Tu, Philip Lister, Brian M. Forster, and OpenStax, © OpenStax, licensed under CC BY-NC-SA 4.0. Access the original for free at openstax.org. Each section page records its own changes from the source. Changes: the chapter-opening figure is the source’s photo, re-encoded for the web, with its alt text rewritten to describe it; the module marks “public health” and “epidemiology” as terms (class no-emphasis, so the source itself gives them no visual styling), which are rendered here as plain prose; the module has no footnote.

Virulence Factors of Eukaryotic PathogensThe Language of Epidemiologists