CDC Reports Rise in Extensively Drug-Resistant Shigella Infections in US

Shigella, a bacterium causing diarrhea and fever, was previously treatable with antibiotics such as azithromycin and ciprofloxacin. 5% of Shigella samples tested nationwide were XDR, meaning they no longer responded to these standard treatments.

Shigella infections typically resolve within a week, even without antibiotics, but cause intense diarrhea, fever, and stomach pain. The infection is not usually deadly for most people but can be life-threatening for immunocompromised individuals and children under 5.

Infection Trends and Transmission An estimated 450,000 Shigella cases occur annually in the US.

As a nationally notifiable disease, cases must be reported to health departments. 5% in 2023. Most cases in 2023 involved patients with no recent travel history, though contaminated food and water during travel can transmit the bacterium.

Sexual contact, including anal sex, also spreads it, with recent XDR outbreaks linked to adult men who have sex with men. About one-third of cases required hospitalization, though no deaths were reported.

Treatment and Prevention Challenges Antibiotics shorten symptoms by a few days but do not alter the need to manage the infection through hydration.

The CDC advises drinking fluids to prevent dehydration and avoiding anti-diarrheal medications like Imodium or Lomotil if blood is present in the stool. No FDA-approved alternative antibiotics exist for XDR Shigella. A Shigella vaccine is not available, though candidates are in clinical trials.

The CDC classifies XDR Shigella as a public health threat requiring increased susceptibility testing and prompt case reporting. Globally, over 1 million people die annually from drug-resistant bacteria, with the World Health Organization projecting a tenfold increase by 2050. Scientists note that resistance genes in Shigella could transfer to other gut bacteria, broadening antibiotic resistance.

Prevention focuses on hygiene and surveillance, as developing effective new antibiotics remains a priority.