The hospitalization rate is the number that should stop you. Of 30 people identified in a multistate outbreak, 25 were hospitalized. That is 83 percent, far above what hepatitis A usually produces, and it reflects both the severity of these infections and the fact that milder cases never got counted.
Federal and state investigators traced the common exposure through food interviews. Of the people questioned, 76 percent reported eating ceviche, 75 percent reported eating raw or undercooked shellfish, and 52 percent reported eating raw or undercooked conchas negras, also called black clams or blood clams. Those rates were substantially higher than what a national food consumption survey would predict.
The CDC concluded that people in the outbreak "may have gotten sick from eating raw or undercooked clams."
Here is the part worth acting on. Hepatitis A is the only common foodborne infection with a vaccine that works both before exposure and, in many cases, after it.
What Investigators Found
Illnesses have been identified in Minnesota, New York and Pennsylvania, with onset dates running from July 30, 2025, to May 1, 2026, based on data reported as of June 18. Those affected ranged in age from 12 to 40, and 57 percent were male. No deaths have been reported.
The implicated product is La Serranita brand concha negra, sold as fresh frozen shell meat in 16-ounce packages and imported from Ecuador. New Jersey health officials have described the clams as illegally imported. The product moved from a New Jersey importer to a New York dealer and was distributed within New York state, with the FDA identifying distribution in Connecticut, Massachusetts, New Jersey, New York, Ohio and Pennsylvania, and noting it may have gone further.
Two things make this outbreak unusual, and both matter for readers.
The timeline is long. Nine months between the first and last identified illness is not typical for a foodborne outbreak, and it happened because the product is frozen. A package bought in October can be eaten in March. The most recent known illness does not close the window.
And the count is almost certainly incomplete. CDC has said the true number of sick people is likely higher and that the outbreak may not be limited to states with known illnesses, because some people recover without medical care and are never tested.
Why Hepatitis A Hits Harder Than Most Food Poisoning
Hepatitis A is a liver infection, not a stomach bug, and that difference explains the hospitalization rate.
Symptoms usually appear 15 to 50 days after exposure, which is a long enough gap that most people never connect the illness to a specific meal. They typically include fatigue, nausea, vomiting, abdominal pain, especially on the right side under the ribs, loss of appetite, low-grade fever, dark urine, pale stools, joint pain, and jaundice, the yellowing of the skin and eyes.
Illness often lasts weeks and sometimes months. Most people recover fully and do not develop chronic infection, but severe disease and liver failure are possible, particularly in adults over 50 and in anyone with existing liver disease.
Cooking destroys the virus. Freezing does not. Raw preparations like ceviche do not cook shellfish, and citrus marinade does not inactivate hepatitis A virus regardless of how long the fish sits in lime juice. That is a common and dangerous misunderstanding.
The Vaccine Is the Point
Hepatitis A vaccine is safe, effective, and widely available, and it is recommended for all children starting at 12 months, for travelers to many countries, for people with chronic liver disease, for men who have sex with men, for people who use drugs, and for anyone experiencing homelessness. Two doses provide long-lasting protection.
Post-exposure prophylaxis is the piece most people do not know about. Someone who is unvaccinated and has a known exposure to hepatitis A can often prevent illness by receiving the vaccine within two weeks of that exposure. For people over 40, people who are immunocompromised, or those with chronic liver disease, a clinician may also consider immune globulin.
The two-week window is why this belongs in a news article rather than a health tips column. If you ate raw black clams or clam ceviche recently and you have never been vaccinated, that is a same-week phone call to a clinician or pharmacy, not a wait-and-see.
Connecticut's health commissioner, Manisha Juthani, made the point directly in a statement urging residents to check their vaccination status, saying of the hepatitis A vaccine that "The vaccine is safe, effective, and widely available."
Who Should Be Most Careful and What to Do Now
Raw shellfish is not an equal-risk food. People who are pregnant, adults over 65, people with liver disease including hepatitis B or C or cirrhosis, and anyone immunocompromised from cancer treatment, transplant medication, or advanced HIV face a meaningfully higher chance of severe outcomes and should consider avoiding raw shellfish entirely.
Anyone with the implicated product should not eat it. Discard it or return it, and wash and sanitize surfaces, containers and utensils that touched it, since hepatitis A can persist on surfaces.
Restaurant diners can reasonably ask where shellfish is sourced. Connecticut's health department made exactly that suggestion, noting that shellfish served in restaurants may come from multiple suppliers operating under different standards.
Anyone who develops jaundice, dark urine, persistent vomiting, severe abdominal pain or confusion should seek medical care promptly, and should mention any raw shellfish consumption so the right test is ordered. Hepatitis A is not routinely tested for unless a clinician suspects it.
What Happens Next
The investigation remains open at CDC and FDA, and case counts are updated as states report. Because the product is frozen with a long shelf life, both agencies have treated the risk as continuing rather than closed, and additional illnesses or additional states would not be surprising.
Traceback work by New York and New Jersey authorities alongside the FDA is ongoing, and the illegal-import finding raises a supply chain question about how the product entered U.S. commerce at all.
The confirmed finding is that 30 people across three states became ill and 25 were hospitalized after exposures pointing to raw black clams. The people most at risk are those who eat raw shellfish and have never been vaccinated. The most useful action is checking hepatitis A vaccination status and seeking the vaccine within two weeks if there was a recent exposure. The central uncertainty is how much of this product is still in freezers.
Frequently Asked Questions
What is the outbreak? A multistate hepatitis A outbreak with 30 identified illnesses in Minnesota, New York and Pennsylvania, potentially linked to imported frozen clams. Twenty-five people were hospitalized, and no deaths were reported.
What food is implicated? La Serranita brand concha negra fresh frozen shell meat from Ecuador, sold in 16-ounce packages and often used to make clam ceviche.
Does lime juice make ceviche safe? No. Citrus marinade does not inactivate hepatitis A virus. Only cooking does.
Can I still prevent illness after eating it? Possibly. Unvaccinated people can often prevent hepatitis A by receiving the vaccine within two weeks of exposure. Contact a clinician promptly.
What symptoms should I watch for? Fatigue, nausea, abdominal pain, dark urine, pale stools, joint pain, and jaundice, typically 15 to 50 days after exposure.
Who should avoid raw shellfish? People who are pregnant, adults over 65, anyone with liver disease, and anyone immunocompromised.
Is the outbreak over? Not formally. The product is frozen with a long shelf life, so agencies have treated the risk as ongoing even though the most recent identified illness was in May.
