A drug-resistant strain of Shigella bacteria causing diarrheal illness is increasing across the United States, according to a new report from the U.S. Centers for Disease Control and Prevention (CDC).
The report, released on Wednesday, April 15, 2026, highlights a steady rise in extensively drug-resistant (XDR) Shigella infections, which are difficult to treat with standard antibiotics. The CDC found that such cases accounted for about 8.5% of infections in 2023.
According to the study, overall drug-resistant Shigella infections have increased significantly since 2011, with data showing a rise from virtually zero cases in 2011–2015 to 8.5% in 2023. Researchers examined more than 16,700 samples collected between January 2011 and October 2023, identifying a clear upward trend in resistance.
Health officials estimate that around 450,000 Shigella infections occur annually in the U.S., meaning tens of thousands of cases may involve the highly resistant XDR strain each year.
The CDC notes that Shigella spreads mainly through the fecal-oral route, including person-to-person contact, contaminated food or water, and certain types of sexual contact. The strain was first identified as drug-resistant in 2016 and has since become more widespread.
Common symptoms include diarrhea that may be bloody or prolonged, fever, and abdominal pain. Symptoms typically appear within one to two days of exposure and last around five to seven days, though some cases may persist longer.
Health experts are urging early medical consultation if symptoms develop. The CDC also recommends preventive measures such as regular handwashing, avoiding swallowing water while swimming, and maintaining proper hygiene during travel.