The U.S. Food and Drug Administration (FDA) and the U.S. Department of Agriculture (USDA) have launched a joint investigation into a new outbreak of Listeria monocytogenes infections. The source of the pathogen has not yet been determined.

It is fairly rare for the two agencies to collaborate on an outbreak investigation. The collaboration suggests that the suspected source of the Listeria monocytogenes infections involves a product(s) under the jurisdiction of both.

As of the posting of the outbreak notice on April 30, ten people have been confirmed as patients. FDA has not reported the ages or locations of the patients. FDA has initiated an onsite inspection and sample testing but has not revealed the location being inspected or what is being tested.

The USDA website says that the agency’s Food Safety and Inspection Service (FSIS) and FDA are currently investigating the outbreak.