Use of population health data to refine diagnostic decision-making for pertussis.

Objective: To improve identification of pertussis cases by developing a decision model that incorporates recent, local, population-level disease incidence.

Design: Retrospective cohort analysis of 443 infants tested for pertussis (2003-7).

Measurements: Three models (based on clinical data only, local disease incidence only, and a combination of clinical data and local disease incidence) to predict pertussis positivity were created with demographic, historical, physical exam, and state-wide pertussis data.

Multistate outbreak of Listeria monocytogenes infection linked to delicatessen turkey meat.

Background: Despite a decreasing incidence of listeriosis in the United States, molecular subtyping has increased the number of recognized outbreaks. In September 2000, the New York City Department of Health identified a cluster of infections caused by Listeria monocytogenes isolates with identical molecular subtypes by pulsed-field gel electrophoresis (PFGE) and ribotyping.

Methods: To determine the magnitude of the outbreak and identify risk factors for infection, we notified state health departments and conducted a case-control study.