Cryptosporidiosis in Georgia

These Epidemiologic Case Studies are based on historical events and include epidemiologic methods that were practiced at the time. Given the historical nature of this content, the methods that are referenced on this site may be outdated practices in some settings. As some of the practices are still used, they continue to offer educational value.

Target Audience

This case study was developed for students and public health professionals interested in learning and practicing specific skills in outbreak investigation, especially outbreaks associated with drinking water. The target audience includes epidemiologists, environmental health specialists, sanitarians, public health nurses, disease investigators, health officers, and physicians.

Learning Objectives

After completing this case study, the student should be able to

  • Discuss epidemiologic clues indicative of a waterborne disease outbreak as opposed to a foodborne disease outbreak
  • Describe a boil-water advisory and discuss problems that might be encountered in issuing such an advisory
  • Help plan a community survey to determine the prevalence and distribution of a health problem
  • Interpret a dose-response analysis for an exposure and development of a disease
  • List activities that should be included in the evaluation of a public water system associated with an outbreak
  • Define turbidity and total coliform count and discuss how each are used to indicate drinking water quality
  • Discuss the typical steps used in the treatment of surface water at a community water treatment plant
  • Describe the clinical features, epidemiology, and control of cryptosporidiosis


Successful completion of basic training in infectious disease epidemiology, descriptive epidemiology, study design, measures of association, and outbreak investigation. The student will also benefit from having familiarity with drinking water treatment processes and evaluation of a water treatment system but will likely rely on others with greater expertise in these areas in a real-life outbreak situation.






3.5 to 4 hours

Continuing Education

Continuing education credits are not available for completing this case study.

Developed By

Jeanette K. Stehr-Green, MD, developed this case study in collaboration with individuals from the Centers for Disease Control and Prevention:

  • National Center for Zoonotic, Vector-borne, and Enteric Diseases
  • National Center for Environmental Health

Original Investigation Team

The following individuals investigated the original outbreak of cryptosporidiosis in Georgia: Edward B. Hayes, MD; Thomas D. Matte, MD, MPH; Thomas R. O’Brien, MD, MPH; Thomas W. McKinley, MPH; Gary S. Logsdon, DSc, PE; Joan B. Rose, PhD; Beth L.P. Ungar, MD; David M. Word, PE; Paul F. Pinsky, MPH; Michael L. Cummings, MD; Margaret A. Wilson, MD, MPH; Earl G. Long, PhD; Eugene S. Hurwitz, MD; and Dennis D. Juranek, DVM, MSc.