Multistate Outbreak Investigation of Salmonella Infections Linked to Kratom: A Focus on Traceback, Laboratory, and Regulatory Activities.

ABSTRACT: During spring 2018, the U.S. Food and Drug Administration (FDA), Centers for Disease Control and Prevention, and state and local public health agencies responded to a multistate outbreak of gastrointestinal illnesses caused by multiple Salmonella serovars and associated with consumption of kratom, a product harvested from a tropical tree native to Southeast Asia. The outbreak included 199 case-patients reported by 41 U.S. states, with illness onset dates ranging 11 from January 2017 to 8 May 2018, leading to 54 hospitalizations and no deaths. Case-patients reported purchasing kratom products from physical and online retail points of service (POSs). Products distributed to 16 POSs where 24 case-patients from 17 states purchased kratom were selected for traceback investigation. Traceback revealed that the kratom was imported from several countries, the most common being Indonesia. Local and state officials collected product samples from case-patients and retail POSs. The FDA collected 76 product samples from POSs and distributors, of which 42 (55%) tested positive for Salmonella. The positive samples exhibited a range of pulsed-field gel electrophoresis patterns and whole genome sequence genetic heterogeneity, and 25 (60%) of 42 samples yielded at least one isolate indistinguishable from one or more outbreak-related clinical isolates. Although it does not exclude a possibility of a single contamination source, the extent of genetic diversity exhibited by the Salmonella isolates recovered from product samples and a lack of traceback convergence suggested that kratom was widely contaminated across multiple sites from which it was grown, harvested, and packaged. As a result of the contamination, kratom products were recalled by numerous firms (both voluntarily and mandatory). Epidemiologic, traceback, and laboratory evidence supported the conclusion that kratom products were associated with illnesses.

An Outbreak Investigation of Scombrotoxin Fish Poisoning Illnesses in the United States Linked to Yellowfin Tuna Imported from Vietnam-2019.

ABSTRACT: Scombrotoxin fish poisoning (SFP) is caused by the ingestion of certain fish species with elevated concentrations of histamine due to decomposition. In fall 2019, the U.S. Food and Drug Administration (FDA) was notified of 51 SFP cases including two hospitalizations from 11 states through the FDA consumer complaint system or directly from state partners. A case patient was defined as an individual who experienced a histamine-type reaction after consumption of tuna imported from Vietnam and an illness onset between 14 August and 24 November 2019. A traceback investigation was initiated at 19 points of service to identify a common tuna source. The FDA and state partners collected 34 product samples throughout the distribution chain, including from a case patient's home, points of service, distributors, and the port of entry. Samples were analyzed for histamine by sensory evaluation and/or chemical testing. Case patients reported exposure to tuna imported from Vietnam. The traceback investigation identified two Vietnamese manufacturers as the sources of the tuna. Twenty-nine samples were confirmed as decomposed by sensory evaluation and/or were positive for elevated histamine concentrations by chemical testing. Both Vietnamese companies were placed on an import alert. Seven U.S. companies and one Vietnamese company initiated voluntary recalls. The FDA released public communication naming the U.S. importers to help suppliers and distributors identify the product and effectuate the foreign company's recall. This SFP outbreak investigation highlights the complexities of the federal outbreak response, specifically related to imported food. Cultural considerations regarding imported foods should be addressed during outbreak responses when timing is critical. Collaboration with countries where confidentiality agreements are not in place can limit information sharing and the speed of public health responses.