CDC probes rare Salmonella outbreak tied to raw oysters as hospitalizations climb

The December holidays are peak season for oysters on the half shell. This year, the Centers for Disease Control and Prevention warned that for dozens of people across the country, that ritual has ended in a hospital bed.

Federal health officials are investigating a multistate outbreak of infections from a rare strain of Salmonella that they say is strongly linked to eating raw oysters, with illnesses stretching back to the first days of summer and no clear source yet identified.

Sixty-four people in 22 states have been sickened with the same strain of Salmonella Telelkebir, the CDC said in a Dec. 23 alert. Twenty of them have been hospitalized. No deaths have been reported.

“People in this outbreak are being hospitalized at a higher rate than expected when compared to other Salmonella outbreaks linked to oysters,” the agency said.

The outbreak, which remains under investigation, highlights the risks that come with eating raw shellfish and the difficulty regulators face tracking a single tainted product through a sprawling seafood supply chain.

Strong link to raw oysters, but no named source

Laboratory testing and interviews with patients point squarely at raw oysters as the likely vehicle.

Of 27 people who told investigators what they ate before getting sick, 20 — about 74% — said they had eaten raw oysters in the week before their symptoms began, the CDC said. By comparison, only about 1.6% of people in a large national food survey report eating raw oysters in a given week.

That gap is a powerful epidemiologic signal. “This suggests that people in this outbreak got sick from eating raw oysters,” the CDC said in its outbreak investigation summary.

At the same time, whole genome sequencing of bacteria from patients’ samples showed the Salmonella strains are “closely related genetically,” an indication the illnesses likely came from a common contaminated source.

Yet as of early January, neither the CDC nor the Food and Drug Administration has named a specific harvest area, distributor or brand. No recalls or harvest closures have been announced in connection with this outbreak.

“CDC and FDA are working to determine if a common source of oysters can be identified,” the agency said.

Cases spread from coast to coast

Illnesses in the outbreak began on dates ranging from June 21 to Nov. 28, 2025. Because it can take several weeks for a person to seek medical care, be tested, and have their infection added to the national database, officials say the true number of people sickened is likely higher than the 64 laboratory-confirmed cases.

Pennsylvania has reported the most illnesses, with 10 cases. New York has seven. New Jersey and Virginia each have six. Georgia has four. Smaller numbers of cases have been reported from states across the map, including Arizona, California, Colorado, Florida, Massachusetts, South Carolina and Texas, among others.

The broad spread suggests the tainted oysters were distributed widely, not confined to a single coastal community or restaurant.

Patients in the outbreak range in age from 10 to 76, with a median age of 52, according to the CDC. Nearly two-thirds are men. Among patients for whom race and ethnicity information were available, most identified as white and non-Hispanic, reflecting who is most likely to eat raw oysters rather than who is biologically most vulnerable to Salmonella.

An unusually high hospitalization rate

Salmonella typically causes diarrhea, fever and stomach cramps. Many people recover without medical treatment in about a week. But the current outbreak appears to be causing more severe disease than usual.

Of 44 patients with available information on outcomes, 20 have been hospitalized — a rate of about 45%. Foodborne disease experts say that is more than double the roughly 20% hospitalization rate commonly seen in Salmonella outbreaks.

The CDC estimates Salmonella causes about 1.35 million infections, 26,500 hospitalizations and 420 deaths each year in the United States from all sources combined. Infections can be especially dangerous for young children, older adults and people with weakened immune systems.

The agency urges anyone with symptoms such as diarrhea lasting more than three days, a fever higher than 102 degrees, bloody diarrhea, vomiting that prevents keeping liquids down, or signs of dehydration — including infrequent urination or dizziness — to seek medical care.

A rare strain, familiar risks

The culprit in this outbreak is Salmonella enterica serotype Telelkebir, a strain public health officials describe as rarely seen in human infections in the United States.

Laboratories participating in the CDC’s PulseNet network used whole genome sequencing to detect and connect cases with this unusual strain. For 59 patients, testing did not predict resistance to any commonly used antibiotics, the CDC said.

Oysters are better known as a vehicle for other pathogens, including Vibrio bacteria and norovirus. In recent years, federal and state officials have issued repeated warnings and recalls tied to those germs in shellfish harvested from the Gulf Coast, the Atlantic, Canada and Mexico.

The new Salmonella cluster adds another pathogen to that list, underscoring that raw oysters can carry a range of microbes that cause illness.

“Raw oysters can be contaminated with germs at any time of year,” the CDC said in its December alert. “Cook them before eating to reduce your risk of food poisoning.”

Why tracing oysters is so difficult

When health officials identify a foodborne outbreak, their next step is to trace what sick people ate back through suppliers and processors to a source. For oysters, that often means a specific growing area in coastal waters, which can then be closed and cleaned up.

That process can move quickly when the trail is clear. In 2023, for example, Florida regulators temporarily closed a wild harvest area near Cedar Key, known as FL‑3012, after Salmonella illnesses were linked to oysters from those waters, and a recall was initiated for product harvested over a two‑month span. Similar targeted warnings followed contamination incidents involving oysters from Prince Edward Island and from a Louisiana harvest area tied to norovirus.

But in many cases, the path from plate to bay is far from straightforward.

Oysters from multiple beds are often commingled at packing plants. They may be shipped to shucking houses, repackaged, and redistributed through multiple wholesalers before they reach a restaurant in a different state. Detailed lot information is not always preserved on menus or invoices that consumers ever see.

Those layers can make it difficult and time‑consuming for investigators to pinpoint a common source, particularly when illnesses are spread over months and across regions.

Until a clear link emerges, officials are reluctant to single out a particular body of water or company.

Holiday warning for a year‑round problem

The timing of the federal alert — Dec. 23, two days before Christmas — put the warning about raw oysters directly into the holiday dining season.

Raw oyster bars and seafood restaurants in coastal and inland cities often see brisk business from late fall through New Year’s, when cold weather and seasonal traditions help drive demand.

The CDC did not advise restaurants to stop serving oysters altogether, but urged them and retailers to follow safe‑handling and cooking guidance and to consider the risk to certain customers.

The agency emphasized that high‑risk groups — children younger than 5, adults 65 and older, pregnant people and those with weakened immune systems — face a greater chance of severe illness from Salmonella and other germs found in raw oysters.

For consumers, the only reliable way to kill bacteria and viruses in oysters is to cook them thoroughly. The CDC advises boiling in‑shell oysters until shells open or steaming them for several minutes, and boiling shucked oysters for at least three minutes or frying them at 375 degrees for at least three minutes. The internal temperature of seafood should reach 145 degrees for at least 15 seconds.

Hot sauce, lemon juice, alcohol and visual inspection are not effective safeguards, officials say.

“You cannot tell if an oyster has germs by looking at it,” the CDC said. “Hot sauce and lemon juice do not kill germs.”

What comes next

The outbreak investigation remains open, and additional illnesses may be added as testing results come in. If regulators identify a specific harvest area or supplier, they could move to close affected waters and initiate targeted recalls, steps taken in previous shellfish‑related outbreaks.

In the meantime, health officials are asking consumers and food businesses to treat every raw oyster as a potential risk.

The plate of oysters that looks and smells fresh on a bed of ice may have traveled hundreds of miles and passed through several hands before reaching the table. Until investigators can say which oysters are safe and which are not, public health officials say the only way to be sure an oyster will not carry Salmonella — or another pathogen — is to eat it cooked.