CDC says there's a new E. coli outbreak, but the source is a mystery

Days after the FDA highlighted a new romaine lettuce recall involving potential E. coli contamination, the Centers for Disease Control and Prevention has announced that it is investigating a multi-state E. coli outbreak linked to the leafy green — though, it notes, it doesn't yet know whether the lettuce is to blame. Illnesses linked to this outbreak have been reported in a total of six states and have resulted in multiple hospitalizations.READ: FDA says more romaine lettuce recalled over risk of E. coli

The CDC published an Investigation Notice on November 10, stating that it is working with regulatory and public health officials, as well as the FDA, to investigate this current E. coli outbreak. A total of 12 infections have been reported involving the strain E. coliO157:H7.

Of those cases, five people have been hospitalized but no deaths had been reported as of November 10. The CDC says that lab testing found the strain behind this outbreak in a sample of romaine lettuce from Tanimura & Antle, the company that issued the recall on November 6.

The recall involved single head romaine lettuce that was packaged in mid-October, but the CDC notes that there isn't enough data at this time to tell whether that lettuce was the cause of these infections. The investigation is looking into whether there may be other products contaminated with this particular strain of E. coli.

At this time, the public is being told to avoid the recalled romaine lettuce and to get in touch with a doctor if E. coli symptoms appear. The full investigation note includes the current details and will be the source of future updates from the CDC.