Federal health officials are still investigating a hepatitis A outbreak linked to imported frozen clams that has sickened 30 people across three states, with illnesses stretching back more than a year.
The Centers for Disease Control and Prevention reported that as of June 18, 2026, cases had been identified in Minnesota, New York and Pennsylvania, with illness onset dates ranging from July 30, 2025 to May 1, 2026. Case patients ranged in age from 12 to 40, and 57 percent were male. Of the 30 people with information available, 25 (83%) were hospitalized. No deaths have been reported.
The hospitalization rate is the figure that stands out. Hepatitis A does not usually kill healthy adults, but it can produce weeks of illness severe enough to require inpatient care, and this outbreak has hospitalized more than four in five identified patients.
The Product Still Sitting in Freezers
What keeps this investigation open is a frozen product with a long shelf life.
The Food and Drug Administration issued a safety alert in April advising restaurants, retailers and consumers not to eat, serve or sell La Serranita brand concha negra fresh frozen shell meat imported from Ecuador, sold in 16-ounce packages. The clams are also known as black clams, blood clams or black conch meat. Dealers in New York and New Jersey recalled the product.
Distribution reached restaurants and retailers in Connecticut, Massachusetts, New Jersey, New York, Ohio and Pennsylvania, and the product may have moved further. Distribution states are not the same as illness states, which is why the alert covers six product states and the case count covers three.
Freezing does not inactivate hepatitis A virus. A package that entered a freezer a year ago carries the same risk today, which is why an alert issued in April still applies. The implicated clam meat was shipped from a New Jersey importer to a New York dealer, according to Food Safety News, and distributed from there.
Interviews pointed consistently at one preparation. Most people interviewed reported eating ceviche and raw or undercooked shellfish, and about half reported eating raw or undercooked black clams, rates higher than would be expected from federal survey data on how often people eat such foods.
An Incubation Period That Defeats Traceback
Hepatitis A is unusually hard to trace, and the reason is arithmetic rather than investigative failure.
The incubation period runs roughly 15 to 50 days. Investigators ask people what they ate in that window, which means asking someone to recall meals from as long as seven weeks earlier. A specific brand of clam in a restaurant ceviche is not something most people would remember or even know.
An infected person is also contagious before feeling ill, typically for about two weeks before symptoms appear. Someone who prepares food during that period can transmit the virus without any indication that anything is wrong, which is how a foodborne outbreak can acquire a secondary person-to-person component.
Detection lags compound both problems. Federal officials note that the true number of sick people is likely higher than reported, since some recover without medical care and are never tested, and recent illnesses may not yet be linked to the outbreak because confirmation takes weeks.
The result is a case count that moves slowly and a source finding that arrives long after exposure. Readers should treat the figure of 30 cases as the most recent official count rather than a current one.
Symptoms and the People at Greatest Risk
Symptoms typically include fatigue, nausea, vomiting, abdominal pain, low appetite, fever, dark urine, pale or clay-colored stools, joint pain, and jaundice, a yellowing of the skin and eyes.
Age changes the picture substantially. Children under six often have no symptoms at all, which means a young child can be infected and infectious while appearing well. Adults are more likely to develop noticeable illness.
Severe outcomes concentrate in identifiable groups. People with chronic liver disease, including hepatitis B or C, are at higher risk of serious illness, as are older adults and people who are immunocompromised. Anyone in those groups who develops jaundice or persistent vomiting should seek medical care rather than waiting it out.
Most people recover fully within weeks to a couple of months without lasting liver damage, and infection produces lifelong immunity. That is genuine reassurance, and it should not be mistaken for a reason to treat the illness casually given the hospitalization rate in this outbreak.
Vaccination, Post-Exposure Options and Reporting
A safe and effective hepatitis A vaccine has been available for decades and is part of the routine childhood immunization series. Adults who were never vaccinated can receive it, and it is recommended for travelers to many countries, people with chronic liver disease and several other groups.
Timing matters after a known exposure. Federal officials advise anyone who ate the implicated frozen clams raw or undercooked within the past 14 days and is not vaccinated to contact a health care provider, because vaccine or immune globulin given within two weeks of exposure can prevent illness or reduce its severity. MedicalDaily reported earlier this year on the initial alert to New York consumers.
For consumers, the practical steps are narrow. Check freezers for the implicated brand and discard it rather than cooking it. Raw or undercooked shellfish carries risk generally, and thorough cooking inactivates the virus. Handwashing with soap and water is effective; alcohol-based sanitizer is not reliable against this virus.
Anyone who suspects a foodborne illness can report it to their local or state health department, which is how case clusters are identified in the first place. Federal officials have not said when the investigation will close or whether additional states will be added.
Key Questions Answered
How many people are sick and where? Thirty illnesses in Minnesota, New York, and Pennsylvania as of June 18, 2026. Twenty-five were hospitalized, and no deaths have been reported.
What food is involved? Imported frozen clams, specifically La Serranita brand concha negra fresh frozen shell meat from Ecuador in 16-ounce packages, most often eaten in ceviche.
Where was the product distributed? To restaurants and retailers in Connecticut, Massachusetts, New Jersey, New York, Ohio and Pennsylvania, and possibly further. Distribution states differ from illness states.
Why is this still a risk months later? Freezing does not inactivate hepatitis A virus, so packages bought long ago remain hazardous.
Why are these outbreaks hard to trace? The incubation period runs 15 to 50 days, so investigators ask people to recall meals from weeks earlier, and infected people are contagious for about two weeks before symptoms appear.
What symptoms should people watch for? Fatigue, nausea, abdominal pain, fever, dark urine, pale stools, and jaundice. Children under six are often asymptomatic.
What can someone do after a possible exposure? Contact a health care provider promptly. Vaccine or immune globulin within two weeks of exposure can prevent or reduce illness.
