Eight of the eleven people interviewed as part of the investigation said they'd consumed kratom "in pills, powder or tea", the CDC notes, adding, "No common brands or suppliers of kratom have been identified".
Kratom, or Mitragyna speciosa, is a plant in the coffee family that's native to Southeast Asia.
While it investigates, the agency is recommending people abstain from using the product. A few months later, in the autumn of 2016, the DEA said it would delay rendering a decision on kratom until the FDA was able to complete a scientific evaluation of the supplement. Known for its stimulant effects, the plant has been considered by governmental agencies as an opioid substitute, a concern that hits home as the United States continues to struggle with an ongoing opioid crisis. The outbreak, which began in October, has resulted in at least 11 people being admitted to hospitals for treatment, but no deaths have been reported.
The federal agency had received confirmation of 28 people across 20 states with infections from Salmonella I 4, , 12:b:- as of February 16, according to the outbreak notice posted today.
The FDA has always been skeptical of the benefits of kratom, having placed import alerts on the substance in 2012 and 2014.
The CDC is urging Kratom users to stop taking the plant in any form because the source of the contamination has not been identified. It can cause psychosis, seizure and death, according to the CDC. Earlier this month, Food and Drug Administrator Scott Gottlieb warned consumers about kratom, saying an FDA analysis shows compounds in the plant act like prescription-strength opioids. There are now no FDA-approved therapeutic uses of kratom and importantly, the FDA has evidence to show that there are significant safety issues associated with its use.
The American Kratom Association and patients who use the supplement for pain control immediately pushed back on that decision.