New tests that detect common foodborne pathogens more rapidly are less likely to trace contamination to the source, since they provide less specific information than older, slower tests, say public health officials. As a consequence, sources of foodborne illnesses outbreaks will not be identified as quickly, state epidemiologists told the Scientific American in a report published Monday. New diagnostic tests for foodborne illnesses caused by Salmonella, Campylobacter and E. coli have allowed public health officials to drop traditional laboratory testing of blood and stool samples. The old, slower lab tests, however, were based on a cultured specimen that revealed a pathogen’s DNA “fingerprint,” which could be shared on the national PulseNet system and matched with other cases, often resulting in the source of the contamination being identified. Timothy F. Jones, Tennessee’s state epidemiologist, told Scientific American that while rapid tests can detect whole classes of Shiga-toxin producing bacteria, and additional bacteria that in the past would have been missed, it won’t produce the DNA fingerprinting needed by PulseNet in order to identify it as a match with a contaminated food. Jones says that part is setting public health back to the day before it had the ability to do DNA fingerprinting. It means outbreaks will be underway longer before they are connected to a specific source, meaning more people will experience foodborne illness. Infectious disease experts say the adoption of the new fast tests by doctors and hospitals mean public heath officials will have to find new ways to monitor and track outbreaks.