A black clams Hepatitis A outbreak has potentially sickened at least 37 people in four states, according to the Centers for Disease Control and Prevention (CDC). Thirty of those patients have been hospitalized. The FDA issued a safety alert about this product in May 2026. And New York reported illnesses from these clams in May 2026.
The case count by state is: Massachusetts (3), Minnesota (3), New York (27), and Pennsylvania (4). The patient age range is from 6 to 40 years old. Illness onset dates range from July 30, 2025 to June 23, 2026. The hospitalization rate is very high, at 81%.
Thirty seven people were interviewed by public health officials. Of those patients, 77% reported eating ceviche (raw fish or shellfish marinated in citrus juice), 76% reported eating raw or undercooked shellfish, and 47% reported eating raw or undercooked conchas negras (black clams) before they got sick. The clams have a black shell and are red in color because they contain hemoglobin, a protein that makes blood red. They are usually eaten raw.
In the FDA safety alert and the outbreak announcement from New York State, the clams are La Serranita Concha Negra Shell Meat that are removed from the shell and sold fresh frozen. The CDC announcement did not confirm this directly, but did link to the FDA safety alert for that brand of black clams. Traceback investigations are ongoing.
If you purchased black clams, check to see if they have been recalled. If they have, do not eat them, serve them, or sell them to others. You can throw the clams away in a secure trash can after first wrapping or double bagging them so others can’t see them, or you can take them back to the store where you bought them or arrange a return with your distributor.
If you ate these clams, especially if they were eaten raw or undercooked, monitor your health for the symptoms of hepatitis A for the next 50 days. That’s how long it can take for symptoms to appear. If you do get sick, see your doctor.
