The E. coli O157:H7 outbreak linked to ready-to-eat chicken wraps has grown to 50 confirmed patients, up from 35 that the Food and Drug Administration reported just one week ago.

Two federal agencies are working the case. The FDA and USDA are investigating "ready-to-eat multi-ingredient chicken wraps" as the cause, and neither agency has named the brand involved or disclosed where the wraps were sold. The split jurisdiction is procedural: the USDA holds authority over poultry, while the FDA covers every other ingredient in the wrap.

The most operationally significant detail for operators is timing. The FDA says the wraps "were proactively removed from the market before the link to the outbreak was confirmed" and are now past shelf life. That means the immediate product risk has passed, but the investigation has not. Both agencies are now examining "possible ingredient level contamination," and the USDA is working to determine whether the implicated chicken made its way into other products — the question that determines whether a recall could widen.

FDA investigators have launched traceback, onsite inspection and sample testing. The agency has not revealed what food is being traced, which locations are under inspection or what is being tested. It first reported the outbreak on Sept. 23.

What does the official count actually mean?

Almost certainly an undercount. The CDC estimates that for every confirmed patient in an E. coli outbreak, 26 infections go undetected, because some people never seek medical care and others are not specifically tested for E. coli. Applied to this outbreak, that ratio implies the true number of infections could exceed 1,300.

The FDA, following standard practice, is not reporting patient ages or locations.

Raw milk cheese outbreak hits young children hardest

A second active outbreak has sharper menu implications for cheese programs. An E. coli O26:H11 outbreak traced to Sierra Nevada Graziers grass-fed raw milk cheeses has sickened 13 people, with eight hospitalized and no deaths confirmed, according to the CDC. Three patients have developed hemolytic uremic syndrome, a condition that causes kidney failure and can lead to brain damage or death.

More than half of the sick people are children 5 years old or younger. The patients are spread across nine states.

State and local public health officials are interviewing ill people or their caregivers about foods eaten in the week before illness. All nine people interviewed so far in this outbreak reported consuming Sierra Nevada Graziers grass-fed raw milk cheese. The FDA has initiated sample collection, though it is not reporting what is being sampled. The agency first reported the outbreak on Sept. 25.

For operators carrying raw-milk cheeses, the case is a reminder that unpasteurized dairy remains one of the most consistently implicated categories in E. coli O26 outbreaks.

Two Listeria outbreaks also active

Two Listeria monocytogenes outbreaks remain under FDA investigation. The first has sickened 11 people; the agency has initiated sample collection but has not determined the pathogen's source. It first posted that outbreak on Sept. 30.

The second Listeria outbreak has increased to 46 patients, up from 44 a week ago. FDA inspectors have begun traceback, but the agency has not revealed what food is being traced. That outbreak was first posted Sept. 23.

In neither case is the FDA reporting patient ages or locations.

With four active investigations spanning wraps, raw-milk cheese and two undetermined Listeria sources, and with the chicken-wrap probe now moving to the ingredient level, operators should expect the possibility of additional product identifications as federal traceback work continues.