Situation summary
As of June 4, 2026, 30 illnesses have been identified as being associated with the outbreak from three states. Illness onset dates range from July 30, 2025, to May 1, 2026. Among identified case-patients, ages range from 12–40 years old and 57% are male. Of 30 people with information available, 25 (83%) have been hospitalized. No deaths have been reported.
State and local public health officials interviewed people about the foods they ate in the 15–50 days before they got sick. Of the people interviewed, 76% reported eating ceviche (raw fish or shellfish marinated in citrus juice), 75% reported eating raw or undercooked shellfish, and 52% reported eating raw or undercooked conchas negras (black clams). These percentages were significantly higher than the percentage of respondents who reported eating ceviche or raw or undercooked seafood or shellfish, including clams, in the FoodNet Population Survey—a survey that helps estimate how often people eat various foods linked to diarrheal illness. This difference suggests that people in this outbreak may have gotten sick from eating raw or undercooked clams.
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.
Outbreak investigation summary
In May 2026, CDC, the US Food and Drug Administration (FDA), and public health and regulatory officials in several states and local jurisdictions began investigating a multistate hepatitis A outbreak potentially linked to frozen clams.
Source of the outbreak
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.
Recalled items
La Serranita-brand concha negra (black shell) shell meat products have been recalled by dealers in New Jersey and New York. Details can be found at:
What you should do
If you learn about an outbreak, follow advice from health officials.
In this outbreak, CDC recommends returning or throwing away frozen conchas negras affected by the recalls detailed in FDA's Safety Alert.
If you think you've been exposed
About hepatitis A
Hepatitis A is a liver infection caused by the hepatitis A virus (HAV). Hepatitis A spreads when someone consumes the virus by eating or drinking something contaminated, or through close personal contact with a person who is infected. Hepatitis A is preventable through vaccination.
Symptoms of hepatitis A
Not everyone with hepatitis A has symptoms, but when symptoms are present, they usually appear 2–7 weeks after exposure and can include:
- Dark urine or clay-colored stools
- Diarrhea
- Feeling tired
- Fever
- Joint pain
- Loss of appetite
- Nausea, stomach pain, throwing up
- Yellow skin or eyes (jaundice)
Adults are more likely than children to have symptoms. People who get hepatitis A might feel sick for a few weeks to several months but usually recover completely.
In rare cases, hepatitis A can lead to hospitalization, liver failure, and even death. Severe disease is more common in older people and in people with other serious health issues, such as chronic liver disease.