Disease Detectives

Use epidemiology skills to investigate disease outbreaks: rates, study design, and prevention.

What this event is about

Students analyze outbreak data, calculate rates, interpret study designs, and recommend public-health actions.

Setup (team of 2, ~50 min, Class II calculator, one double-sided 8.5×11 note sheet)

Put formulas and study-design comparison tables on the note sheet; this event is process/interpretation, not memorizing pathogen→disease pairs.
Background & Surveillance (~⅓): clinical vs public health approach; history of epi; roles/steps in solving health problems; natural history & spectrum of disease (infectious and noninfectious causes in broad terms); CDC glossary terms; 5-step surveillance process, types, and attributes.
Outbreak Investigation (~⅓): experimental vs observational studies; case-control, cohort, ecological, cross-sectional — advantages/disadvantages and when to use each.
Drill outbreak steps, person-place-time case definitions, agent-host-environment triad, and chain of transmission.
Interpret epi curves, line listings, cluster maps, subdivided tables, PFGE gels, SNP mapping, PulseNet concept.
Calculate and interpret attack rate, relative risk, odds ratio; revise hypotheses from data; apply Bradford Hill vs Koch’s/Evan’s postulates and newer causality models (DAGs, sufficient/component cause, GRADE) as listed.
Patterns, Control, Prevention (~⅓): read charts/tables/graphs; compute risk/frequency ratio, proportion, incidence proportion (attack rate), incidence rate, prevalence, death rate, mortality rate; strategies of control and levels of prevention.
State & Nationals only: biases/confounding/errors by study design; herd immunity; vaccine effectiveness vs efficacy methods and calculations. Timed practice tests weekly.

Always write units and show the formula. Bring a clean formula sheet if rules allow note sheets.