Salmonella Outbreak in 20 States Linked to Popular Herbal Supplement Kratom

A popular herbal supplement that some people use in lieu of powerful opioid drugs has been linked to an outbreak of salmonella, the Centers for Disease Control and Prevention reported Tuesday.

So far 28 people in 20 states are believed to have been sickened by contaminated kratom, a plant native to Southeast Asia that’s variously ingested as pills or powder or brewed into tea. Eleven people have been hospitalized.

Laura Gieraltowski, the CDC’s foodborne outbreak team lead, said it’s not yet known how the kratom would have come to be contaminated with salmonella, noting it could have happened in processing, or the plants could have been contaminated in the field. But Gieraltowski said the CDC has seen outbreaks caused by supplements before, including powders used in smoothies.

She suggested there are probably more cases that haven’t come to the attention of the medical community. Salmonella causes diarrhea, fever and stomach cramps that can last for up to a week, but most people recover without treatment.

Kratom can be purchased easily and legally — at least at present. But it is under intense scrutiny by the Food and Drug Administration. Earlier this month the agency reported that its studies had found the plant was an opioid.

“Kratom should not be used to treat medical conditions, nor should it be used as an alternative to prescription opioids,” FDA Commissioner Scott Gottlieb said in a statement. “There is no evidence to indicate that kratom is safe or effective for any medical use.”

In 2016 the Drug Enforcement Administration touched off a firestorm when it announced that on an emergency basis it was going to unilaterally classify ingredients in the supplement as a Schedule I drug. Schedule I drugs are defined as having no accepted medical use and a high risk for abuse.

Other drugs in that classification include heroin, ecstasy and LSD.

The American Kratom Association and patients who use the supplement for pain control immediately pushed back on that decision. 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.

There have been several signs since then that the legal status of the supplement may be headed for a change.

In an earlier statement issued last fall, Gottlieb warned that the agency knew of 36 deaths linked to kratom use.

Kratom goes by a variety of names including Thang, Kakuam, Thom, Ketom, and Biak.

The CDC said so far the outbreak investigation has not pointed to a common brand or supplier of the supplement.

This story was originally published by STAT, an online publication of Boston Globe Media that covers health, medicine, and scientific discovery.