It's about to get faster and easier to diagnose food poisoning. But there's a downside: It could make it harder to spot and solve dangerous outbreaks.

Next-generation tests that could reach medical labs as early as next year could shave a few days off the time needed to tell whether E. coli, salmonella or other caused an illness. That could allow doctors to treat diseases more quickly.

The problem is the new tests can't differentiate between bacteria subtypes. That fingerprint is what researchers use to identify the source of the .

Health officials that use the new could still send samples to a lab so that the older, slower test also could be performed. But it's not clear who would pay for that extra step.