During the recent E. coli spinach contamination outbreak, officials at the Wisconsin state public health lab posted E. coli patterns on a PulseNet list serve that helps track this pathogen. Not long after, health department analysts in Oregon were alerted to this information, and linked an E. coli case in their state to a possible bag of spinach.

This is a concrete example of how the online public health network – PulseNet — is helping officials track disease outbreaks, says Sarah Pressman Lovinger. PulseNet is a national network of public health and food regulatory agency laboratories coordinated by the Centers for Disease Control and Prevention. The network consists of: state health departments, local health departments, and federal agencies including the CDC, USDA/FSIS, and FDA.

PulseNet participants perform standardized molecular subtyping of foodborne disease-causing bacteria by pulsed-field gel electrophoresis. PFGE can be used to distinguish strains of organisms such as Escherichia coli O157:H7, Salmonella, Shigella, Listeria, or Campylobacter at the DNA level. DNA "fingerprints," or patterns, are submitted electronically to a dynamic database at the CDC. These databases are available on-demand to participants—this allows for rapid comparison of the patterns.