Federal officials and public health officials in several jurisdictions are investigating a multistate hepatitis A outbreak potentially linked to imported frozen clams.
As of September 17, 2026, 37 illnesses have been identified as being associated with the outbreak from four states - New York (27), Pennsylvania (4), Massachusetts (3) and Minnesota (3).
Illness onset dates range from July 30, 2025, to June 23, 2026. Of 37 people with information available, 30 (81%) have been hospitalized. No deaths have been reported.
“Of the people interviewed, 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),” the CDC said. Further analysis showed that imported frozen clams were the likely source of infection.
During the outbreak, epidemiologic data showed that imported frozen clams may have been contaminated with hepatitis A virus and made people sick in this outbreak. Traceback investigations are ongoing to identify the source or sources of frozen clams that were consumed raw or undercooked by people who are ill.
The true number of sick people in this outbreak is likely higher than the number reported, and this outbreak may not be limited to the states with known illnesses. This is because some people may recover without medical care and are not tested for hepatitis A virus. In addition, recent illnesses may not yet be reported as it usually takes weeks to determine if a sick person is part of an outbreak.
La Serranita-brand concha negra (black shell) shell meat products have been recalled by dealers in New Jersey and New York.