outbreak-investigation

name	outbreak-investigation
description	Systematic approach to outbreak investigation using CDC guidelines. Assists with case definition, epidemic curve analysis, and source identification.

Outbreak Investigation Assistant

Overview

The Outbreak Investigation Assistant provides structured guidance through the CDC's systematic approach to disease outbreak investigation. It assists public health professionals, infection preventionists, and epidemiologists in conducting rigorous, step-by-step outbreak investigations from initial detection through final reporting.

Clinical Context

Disease outbreaks require rapid, systematic investigation to identify the source, mode of transmission, and at-risk populations, enabling effective control measures. The CDC's 10-step framework provides a standardized approach used worldwide for investigating outbreaks of foodborne illness, healthcare-associated infections, respiratory pathogens, and emerging infectious diseases.

Timely outbreak investigation is critical: each day of delay in identifying a common source allows additional exposures and cases. This tool helps investigation teams stay organized and methodical under the time pressure of an active outbreak.

Features

• CDC 10-Step Investigation Guide: Complete framework with detailed actions, tools, and checklists for each investigation phase
• Epidemic Curve Analysis: Automated analysis of onset dates to classify outbreak patterns (point source, propagated, continuous, mixed) and estimate exposure timing
• Attack Rate Calculation: Calculate attack rates for exposed and unexposed groups
• Odds Ratio (Case-Control): 2x2 table analysis with 95% confidence intervals for case-control studies
• Relative Risk (Cohort): 2x2 table analysis with 95% confidence intervals for cohort studies

Investigation Steps Covered

1. Verify diagnosis and confirm outbreak
2. Define cases and conduct active case finding
3. Descriptive epidemiology (person, place, time)
4. Develop hypotheses about source and transmission
5. Evaluate hypotheses with analytic epidemiology
6. Refine hypotheses and conduct additional studies
7. Implement control and prevention measures
8. Communicate findings to stakeholders
9. Maintain surveillance for new cases
10. Prepare final investigation report

References

• CDC. "Principles of Epidemiology in Public Health Practice." 3rd Ed. Self-Study Course SS1978.
• Goodman RA, et al. Field Epidemiology. 3rd Ed. Oxford University Press, 2013.
• Reingold AL. "Outbreak Investigations -- A Perspective." Emerg Infect Dis. 1998;4(1):21-27.
• WHO. "Foodborne Disease Outbreaks: Guidelines for Investigation and Control." 2008.