Food Poisoning Outbreak_lthaikruea

Food Poisoning Outbreak

Lakkana Thaikruea, M.D., M.S., PhD.

Community Medicine Dept Faculty of Medicine, Chiang Mai University, Thailand

Reference

Handicapped Sport Day Province X, 25-36 August 1990

Methods • Study design: Retrospective cohort • Population: Participants in sport event • Descriptive study – Time, place, person – Environmental survey

• Analytic study – Relative risk, 95% confidence intervals – Unconditional logistic regression

The participants, Cafeteria of campus

Food Items of Dinner Éclair

Beef curry

Salted egg

Kitchen Number 1

Kitchen Number 1 (cont.)

Kitchen Number 1 (cont.)

Kitchen Number 2

Kitchen Number 2 (cont.)

Ear swab

Cook A

Throat swab

Cook B: Ear swab

Cook C: Throat swab

Descriptive Study • Person – Characteristics – Incidence rates (or Attack rates) – Signs and symptoms

• Time – Exposure time, Onset of symptom (s) – Incubation period

• Place – Environment – Sanitation – Process

Analytic Study • Univariate analysis – Compare attack rates by food items – relative risk, 95 % confidence interval

• Stratified analysis – Control for confounding factors (few variables) – Check interaction

• Multivariate analysis – Control for confounding factors (many variables) – Multiple logistic regression-unconditional

Crude Relative Risk

The more people ate, the more people got sick Versus Contaminated pieces

Multivariate Analysis • Unconditional logistic regression • Adjusted RR 12 (95%CI = 9, 22) • Eating éclairs was associated with food poisoning illness

Laboratory Results: Food Specimens

Laboratory Results: Cooks

Laboratory results: Confirm

Six month old boy who ate 1 item of suspected meal and ill