Fecal Transplant Treatments Might Transmit Monkeypox: FDA

Lucy Hicks

August 25, 2022

The monkeypox virus may potentially spread through fecal microbiota transplantation (FMT) products, according to a safety alert issued this week by the US Food and Drug Administration (FDA). While the risk of such transmission is unknown, the agency said that additional safety protections are needed.

Monkeypox virus DNA has been detected in rectal swabs as well as in stool samples, according to recent studies. In one study published earlier this month in the journal Nature, researchers confirmed monkeypox exposure in three asymptomatic men from rectal swabs, and isolated viable viral DNA from two of those swabs.

"This information suggests that monkeypox virus may be transmitted through FMT products, although the risk of such transmission is unknown," the agency stated. It is also not known if the monkeypox virus can spread through feces or from individuals with asymptomatic infections.

The FDA advised additional precautions for any investigational use of FMT involving stool donated since March 15, including:

  • Donor screening targeted at identifying donors who are at high risk for monkeypox or who are currently or may have been recently infected with the virus

  • Development of exclusion criteria based on screening questions

  • Informed consent about the potential for the transmission of monkeypox virus via FMT from donors who may have asymptomatic monkeypox infection

FMT has been demonstrated to safely and effectively treat severe, refractory, or recurrent Clostridioides difficile (C difficile) infection, and has been used in experimental treatments for ulcerative colitis and irritable bowel syndrome, among other conditions.

The FDA said they were notifying Investigational New Drug Application (IND) holders about the potential for transmission of monkeypox virus through FMT, and that these holders need to implement additional safety measures.

The agency encourages healthcare professionals and patients to report any suspected adverse events or side effects related to FMT products through MedWatch: The FDA Safety Information and Adverse Event Reporting program.

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