Most people learn about a foodborne outbreak when a brand gets named, and a recall lands in the news. By that point, the investigation is often months old.
The Food and Drug Administration publishes the earlier stage. Its CORE Network investigation table lists outbreak and adverse event investigations as they are opened, including ones where no product has been identified and no warning has been issued. Anyone can read it.
Knowing how to read it is genuinely useful, because it explains something that otherwise looks like agencies withholding information. Several active outbreaks sit on that table at any given time with no public advisory attached, and there is a documented reason.
What the Table Is and What It Shows
CORE stands for Coordinated Outbreak Response and Evaluation. The table lists investigations the network is managing, with columns for the date posted, a reference number, the pathogen, any product linked to illnesses, the total case count, the investigation status, the outbreak status, and check marks showing whether a recall, traceback, on-site inspection, or sampling has begun.
The FDA notes that investigations sit at very different stages, some with limited information and others near completion.
Two columns are easy to confuse. Investigation status describes whether the FDA's work is active or closed. Outbreak status describes whether people are still getting sick. An entry can read "active" investigation and "ended" outbreak at the same time, meaning illnesses have stopped, but the agency has not finished determining what caused them.
The product column frequently reads "Not Yet Identified." That is the entire reason many of these investigations never generate a headline.
Why Some Outbreaks Get an Advisory, and Others Do Not
The threshold is specific, and the FDA states it plainly on the page. A public health advisory is issued for investigations that have produced specific, actionable steps for consumers to take.
If investigators cannot name a food, there is no action to recommend. Telling the public that an unidentified product somewhere in the food supply is making people sick does not help anyone shop differently, and it may push people away from whole categories of food that are not implicated.
The agency also applies a naming standard. For adverse event investigations, which rely on self-reported data, the FDA says it will indicate only a product category in the table and "will not publicly name a specific product until there is sufficient evidence" implicating it.
That standard exists because premature naming causes real damage. A wrongly implicated grower or brand can lose a season of sales, and a retracted accusation makes the next warning less credible.
What the Current Table Looks Like
The version posted July 22 illustrates the pattern well.
Some entries carry full advisories because investigators identified a product. An E. coli O145:H28 investigation tied to frozen blueberries has an advisory and a recall. An infant botulism investigation linked to powdered infant formula has an advisory, a recall, an inspection, and sampling. A Listeria monocytogenes investigation involving requeson and soft ricotta cheese has the same.
Others do not. A Cyclospora investigation with 72 cases lists no identified product and no advisory, only a traceback. A Salmonella Javiana investigation with 106 cases is in the same position, as is a Listeria investigation with 8 cases. A Salmonella Oranienburg cluster grew from 69 to 81 cases without a named food.
Read together, the table shows something the recall news cycle hides: at any moment, several outbreaks with substantial case counts are unsolved, and the absence of a warning reflects the absence of an answer rather than the absence of a problem.
Why "No Source Identified" Is Not the Same as "No Risk"
This is the practical takeaway, and it cuts both ways.
There is no product-specific step to take for an unsolved outbreak. General food safety practices still apply: refrigerate perishables promptly, use separate cutting boards for raw meat and produce, wash hands and surfaces, cook to safe internal temperatures, and avoid unpasteurized dairy.
What is not warranted is avoiding entire food categories on the basis of an unsolved cluster. Fresh produce carries real nutritional value, and agencies have not advised general avoidance during any of the current unsourced investigations.
The single most useful thing an individual can do is also the least intuitive. If you are diagnosed with a foodborne infection, the interview a health department conducts is the raw material investigators use to identify a source. The FDA's own guidance asks people with symptoms to talk to their provider and to public health officials and give details about what they ate, noting this often helps solve emerging outbreaks.
Some infections also require a specifically requested test. Routine stool panels do not automatically screen for every pathogen, so a clinician may need to order the right one.
How to Use These Pages Without Panicking
Check the CORE table when you hear about a recall and want to know whether it is connected to something larger, or when you have been ill and want to see whether a cluster matches your timing and location. The CDC maintains a parallel list of current foodborne outbreak investigations with its own case counts.
Expect the two to differ. States may count probable and confirmed cases while CDC surveillance reflects laboratory-confirmed cases reported to the agency, and reporting lags mean both understate reality.
Do not treat a rising number on the table as a reason to change your diet in the absence of a named product. Do treat a new advisory as a reason to check your refrigerator.
Anyone with bloody diarrhea, a fever above 102 degrees, diarrhea lasting more than three days, or signs of dehydration should contact a clinician rather than waiting to see whether a recall appears.
The FDA updates the table regularly and adds a "What's New" summary at the top listing newly posted investigations, case count changes, and closures. That summary is the fastest way to see what moved since the last time you looked.
Frequently Asked Questions
What is the CORE Network table? It is a public FDA page listing outbreak and adverse event investigations the agency's Coordinated Outbreak Response and Evaluation teams are managing, including ones without an identified product.
Why does FDA not warn the public about every outbreak on it? The agency issues a public advisory when an investigation produces specific, actionable steps for consumers. Without a named food, there is no action to recommend.
What does "Not Yet Identified" mean? Investigators have linked a group of illnesses through laboratory or epidemiological data but have not determined which food caused them.
Can an investigation be active while the outbreak has ended? Yes. Those are separate columns. Illnesses can stop while the agency continues working to identify the cause.
Why do FDA and CDC case counts differ from state numbers? States may include probable and confirmed cases, while CDC surveillance reflects laboratory-confirmed cases reported to the agency. Reporting lags affect both.
What should I do if I get sick? Contact a clinician, ask whether testing is needed, and cooperate fully with any health department interview. Those interviews are the primary tool investigators use to identify sources.
When should I seek urgent care? Bloody diarrhea, fever above 102 degrees, diarrhea lasting more than three days, or signs of dehydration warrant prompt medical attention.
