Federal and state health officials are investigating a multi-state outbreak of Hepatitis A infections that has been linked to imported frozen clams.
As of September 17, 2026, 37 illnesses have been identified in 4 states: Massachusetts, Minnesota, New York, and Pennsylvania. The illness onset dates range from July 2025 to June 2026.
No deaths havee been reported, but the outbreak has a high rate of hospitalization. Of the 37 people who got sick, 30 people (81%) had to be hospitalized.
In interviews with sick people about what they ate in the 15 to 50 days before symptoms, 77% reported eating ceviche, 76% reported eating raw or undercooked shellfish, and 47% reported eating raw or undercooked conchas negras (black clams).
Investigators say this evidence suggests that raw or undercooked clams are the likely source of the outbreak.
The outbreak has been traced to La Serranita-brand concha negra (black shell) shell meat, which is a fresh-frozen shellfish that is imported from Ecuador.
According to the FDA’s safety alert, this product was distributed to restaurants and retailers in Connecticut, Massachusetts, New Jersey, New York, Ohio, and Pennsylvania, and may have reached other states.
Hepatitis A is a liver infection that spreads through contaminated food or water, or close contact with an infected person. Symptoms can include dark urine, clay-colored stools, fatigue, fever, joint pain, nausea, vomiting, and jaundice (yellowing of the skin or eyes).
Anyone who ate frozen La Serranita-brand concha negra (black clams) or other frozen clams that were served raw or undercooked within the last 14 days and is not vaccinated against hepatitis A is encouraged to contact a health care provider to discuss post-exposure prophylaxis.
Source: Multistate Hepatitis A Outbreak Potentially Linked to Frozen Clams