A drug-resistant strain of shigella infections, which cause diarrhea, are increasing in the United States, according to federal health officials.

In an April 9 report from the Centers for Disease Control and Prevention, officials found the infections, which have no Food and Drug Administration–approved oral treatment, have jumped 8.5% from 2011 to 2023.

Officials called the increase "a public health threat," especially since shigella is spread easily from person to person through fecal-oral transmission, sexual contact or through contaminated food and water. Shigella bacteria is responsible for an estimated 450,000 infections each year nationwide.

"Strengthened surveillance, timely reporting and targeted prevention strategies are needed to limit transmission of XDR (extensively drug-resistant) Shigella strains," the report noted.

Historically in the U.S., shigellosis − the illness that comes from shigella infections − primarily affected children, but the data from 2016 to 2023 in the latest report showed cases were predominantly non-Hispanic White men.