Within a one-year period, dozens of people in at least 10 states fell ill from multidrug-resistant salmonella bacteria after spending too much time handling their friendly "pocket pets" -- like hamsters, mice and rats. Health officials were able to link the cases using a database called PulseNet.

Coordinated by the Centers for Disease Control and Prevention (CDC), PulseNet is a national network of public health and food regulatory agency laboratories. It consists of state and local health departments, as well as federal agencies such as the CDC, the U.S. Department of Agriculture and Food Safety and Inspection Service, and the Food and Drug Administration.

PulseNet's role is to detect food-borne disease case clusters, facilitate early identification of common source outbreaks, assist epidemiologists in investigating outbreaks, separating outbreak-associated cases from other sporadic cases, assisting in rapidly identifying the source of outbreaks, and acting as a rapid and effective means of communication between public health laboratories, according to the PulseNet Web site.

In the case of the pocket pet salmonella illness outbreak -- many victims of which were children who were hospitalized for vomiting, fever and severe diarrhea, and who spread the illness to others -- PulseNet detected 28 other cases from December 2003 to October 2004. Cases were confirmed in Georgia, Illinois, Missouri, Pennsylvania, Kentucky, South Carolina, Michigan, Minnesota, North Carolina and New Jersey.