How are outbreaks of foodborne disease detected?
The initial clue that an outbreak is occurring can come in various ways. It may be when a person realizes that several other people who were all together at an event have become ill and he or she calls the local health department. It may be when a physician realizes she has seen more than the usual number of patients with the same illness. It may be when a county health department gets an unusually large number of reports of illness. The hardest outbreaks to detect are those that are spread over a large geographic area, with only a few cases in each state. These outbreaks can be detected by combining surveillance reports at the regional or national level and looking for increases in infections of a specific type. This is why state public health laboratories determine the serotype of Salmonella bacteria isolated from people. New “DNA fingerprinting” technologies can make detecting outbreaks easier too. For example, the new molecular subtyping network, PulseNet, allows state laboratories
