Campylobacter jejuni Outbreak Linked to Raw Oysters in Rhode Island, 2021

•This is the first Campylobacter outbreak linked to oysters in Rhode Island.•Wild birds were identified as the likely source of contamination of the oysters.•Floating gear for oyster cages could create a risk of Campylobacter contamination.•Fecal coliform in water was not a good indicator of Campylobacter contamination.•Fecal coliform in shellfish meats covaried with Campylobacter in shellfish meats. Oysters and other shellfish are not a food that is commonly highlighted as high risk for Campylobacter contamination. The Rhode Island Department of Health (RIDOH) conducted a multiagency investigation of a Campylobacter jejuni outbreak that was linked to the consumption of raw oysters; the first such outbreak detected in Rhode Island. The environmental investigation identified birds as the likely source of contamination of the aquacultured oysters. As a result of this outbreak response, several investigative processes and best practice recommendations are offered. 1) RIDOH will be including exposure to raw shellfish as a question on their case report forms to better identify future oyster-related Campylobacter clusters. 2) It is important that shellfish aquaculture farms be aware of the risks of using floating gear to hold oyster cages, and of the importance of using bird abatement to keep birds off floating aquaculture gear to prevent contamination of oysters from bird feces. 3) It should be recognized that fecal coliform water samples collected near an oyster aquaculture farm may not act as an adequate indicator for the presence of Campylobacter. 4) For the first time, Rhode Island has developed guidelines for closure and re-opening of oyster harvest areas due to contamination with Campylobacter. It is hoped that increased awareness and mitigation of the described risk factors will help prevent future similar outbreaks of illness.