EIS Case Studies

Student Guide #873-703 [PDF – 16 pages]. Case study based on a 1985 outbreak with unknown etiology and mode of transmission in multiple states. Updated in 2003.

Learning Objectives

After completing this case study, students should be able to

• List the key tasks involved in investigating epidemics of unknown cause
• Describe the roles, responsibilities, and relationships of federal versus state public health agencies in a field investigation
• Assign appropriate priority to key tasks during an investigation
• Describe jurisdictions of health agencies at various levels of government

Student Guide #731-703 [PDF – 12 pages]. Case study based on the classic studies of Doll and Hill in the 1950s. Addresses study design, interpretation of measures of association, and impact of association. Updated in 2003.

Learning Objectives

After completing this case study, students should be able to

• Discuss the elements of study design, and the advantages and disadvantages of case-control versus prospective cohort studies
• Discuss some of the biases which might have affected these studies
• Calculate a rate ratio, rate difference, odds ratio, and attributable risk percent
• Interpret each measure and describe each measure’s use
• Review the criteria for causation

Student Guide #811-705 [PDF – 15 pages]. Case study based on a 1980–1982 multicenter case-control study. Addresses bias and analysis of case-control studies. Updated in 2005.

Learning Objectives

After completing this case study, students should be able to

• Outline the sequence of an epidemiologic analysis
• Discuss the biases of particular concern in case-control studies and ways to minimize their influence
• Describe why and when to use crude and adjusted odds ratios and 95% confidence intervals, and how to interpret them
• Define and recognize effect modification and confounding

Student Guide #401-303 [PDF – 12 pages]. Case study of a classic, straightforward outbreak investigation in a defined population. Based on a 1940 outbreak of Staphylococcus aureus among church picnic attendees. Additional material: Compendium of Acute Foodborne and Waterborne Diseases [PDF – 7 pages]. Updated in 2003.

Learning Objectives

After completing this case study, students should be able to

• Define the terms cluster, outbreak and epidemic
• List the steps in the investigation of an outbreak
• Draw, interpret and describe the value of the epidemic curve
• Calculate and compare food-specific attack rates to identify possible vehicles
• List reasons for investigating an outbreak that has apparently ended

Student Guide #891-903[PDF – 11 pages]. Case study of a surveillance system. Updated in 2003.

Learning Objectives

After completing this case study, students should be able to

• Define incidence, prevalence, and case-fatality rate
• Define surveillance and identify the key features of a surveillance system
• List the types of information that should be collected on a surveillance case report form
• List the factors that can account for a change in the reported incidence of a disease
• Define sensitivity of a surveillance system, and the effect of different case definitions on sensitivity

Student Guide #731-705 [PDF – 12 pages]. Case study of a hypothetical health department anticipating the release of the first HIV antibody test in 1985. Focus is on screening. Updated in 2003.

Learning Objectives

After completing this case study, students should be able to

• Define and perform calculations of sensitivity, specificity, predictive-value positive and predictive-value negative
• Describe the relationship between prevalence and predictive value
• Discuss the trade-offs between sensitivity and specificity
• List the principles of a good screening program

Student Guide #912-303 [PDF – 16 pages]. Case study based on a community outbreak of Legionnaires’ disease in Bogalusa, Louisiana in 1989. Addresses the steps of a field investigation and a case-control study.. Updated in 2003.

Learning Objectives

After completing this case study, students should be able to

• Discuss the relationship between and roles of state-based and Atlanta-based EIS officers in a field investigation
• Develop an epidemiologic case definition
• Calculate power for a case-control study
• Describe different sources of controls for a community-based outbreak

Student Guide #941-903 [PDF – 19 pages]. Case study based on surveillance and investigation activities of the Oregon Health Division between 1986 and 1995. Updated in 2003.

Learning Objectives

After completing this case study, students should be able to

• List the process and criteria for placing a disease or condition on a state or national notifiable disease list
• List the categories of information that should be included in a surveillance instrument
• Summarize and interpret surveillance data
• Recognize difficulties in balancing public health concerns with consumer and industry considerations in emerging issues

Student Guide #711-903 [PDF – 12 pages]. Case study based on an infectious disease outbreak investigation in Texas.

Learning Objectives

After completing this case study, students should be able to

• Discuss the advantages and disadvantages of using a sensitive and/or specific case definition in an epidemic investigation
• Calculate vaccine efficacy and discuss its interpretation
• Discuss the advantages and limitations of selecting a specific age as the recommended target date for administering vaccinations