Ongoing Multistate Salmonellosis Outbreak Linked to Controversial Kratom Supplement

By Alexandra Fraser, NACCHO Environmental Health Intern

A multistate outbreak of Salmonellosis has been linked to the consumption of a product called “kratom”. From March 14 to April 5, 2018 the number of Salmonella cases confirmed by the Centers for Disease Control and Prevention (CDC) increased by more than 50%, up to 132 people in 38 states [1] [2]. Multiple strains of Salmonella are associated with this outbreak. Of the 96 cases with data available, 40% include people hospitalized from Salmonella, with no reported deaths at this time [1]. According to the CDC, this hospitalization rate is concerning, as the majority of patients with Salmonella typically recover without formal treatment [6]. No common brands or suppliers of kratom products have been identified at this time, and the investigation is ongoing.

Separate from the infectious disease outbreak, the Food and Drug Administration (FDA) is currently evaluating kratom’s toxicity, as there is no CDC- or  FDA-approved safe use of kratom. While no conclusions have been reached, the FDA publicly expressed its concerns regarding the safety of kratom due to multiple reports of serious adverse effects, including death, among its users [2]. Prior to the current Salmonella outbreak, 36 deaths had been attributed to kratom, according to a report from the American Journal of Health-System Pharmacy [5].

What is kratom?

Kratom, or Mitragyna speciosa, is a native Southeast Asian plant with psychoactive properties that has found its’ way into the mainstream herbal supplement market, as well as smoke and head shops. Kratom is commonly found in powdered form, pills, capsules, leaves, and tea [2], and people use it as an opioid substitute for pain management, for addiction withdrawals, and for recreational purposes [4]. Common names identified by the U.S. Drug Enforcement Administration (DEA) include the following: mitragynine extract, biak-biak, cratom, gratom, ithang, kakuam, katawn, kedemba, ketum, krathom, krton, mambog, madat, Maeng da leaf, nauclea, Nauclea speciose, and thang [2].

How do we know the Salmonella outbreak comes from kratom?

Of the cases matching outbreak strains by pulsed-field gel electrophoresis (PFGE), 73% reported a recent history of kratom use [2]. In addition, microbiologic analyses have directly linked multiple outbreak strains of Salmonella to specific kratom products from a variety of retailers and from leftover samples made available by cases. “Testing by the FDA and states has revealed Salmonella in several brands of kratom, meaning that multiple kratom and kratom-containing brands and retailers are supplying contaminated product to the public” [2]. During an investigation at Oregon-based retailer Torched Illusions, epidemiologists from the Oregon Health Authority (OHA), along with representatives of the Washington County Public Health and the FDA, purchased kratom capsules and powders for testing. Fifteen samples tested positive for multiple strains of Salmonella [7]. While the strains did not match the national outbreak strain, the results indicate an unprecedented level of contamination and suggest that cases with other sub-types may be part of the national kratom outbreak [7].

What is being done about the outbreak?

While the exact source of the outbreak is not yet  confirmed, the FDA is advising consumers to avoid any form of “kratom or its psychoactive compounds, mitragynine and 7-hydroxymitragynine” and to discard all kratom products immediately [3]. The FDA also warns consumers that some products may not be explicitly labeled as containing kratom. Therefore, the FDA encourages people to report all symptoms to their medical providers even if they do not believe they have consumed kratom [1]. By testing infected individuals who unknowingly consumed products with kratom, officials can link them to the outbreak through PFGE matches.

Several retailers have voluntarily recalled their products secondary to samples testing positive for the Salmonella pathogen [2]. However, Triangle Pharmanaturals, LLC, the supplier identified in the Oregon investigation of Torched Illusions, “failed to cooperate with the FDA’s request to conduct a voluntary recall.” The FDA issued a mandatory recall order for “all food products containing powdered kratom manufactured, processed, packed, or held by Triangle Pharmanaturals LLC” [3]. This was the first time the FDA issued a  mandatory recall order in response to a company’s refusal to recall its products after an FDA notification of an opportunity for a voluntary recall [3].

Local health departments are also working to protect their jurisdictions from Salmonellosis by increasing awareness about the dangers of kratom use. Since kratom is legal to sell in most states, local health departments may have to use creative methods to limit the sale and consumption of kratom, such as conducting independent lab tests to help confirm a link to the outbreak or releasing public service announcements. In Oregon, the Multnomah County and Washington County Health Departments informed local retailers of the national outbreak and advised retailers to stop selling kratom products. Other recommendations for retailers include keeping detailed records of kratom purchases and informing customers of the risks and warning signs of Salmonella [8].

Ultimately, preventing new cases and identifying the source of this outbreak requires a collaborative effort between local, state, and federal regulatory agencies, and a continued effort by communicable disease staff to ask about kratom use among Salmonella cases. Both the sale and consumption of kratom are not recommended at this time.

To stay up to date, check out the latest CDC Salmonella case counts here and FDA updates here


  5. White, C Michael (2018). “Pharmacologic and clinical assessment of kratom”. American journal of health-system pharmacy(1079-2082), 75 (5), 261.

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