CDC Warns of Rising Drug-Resistant Shigella Cases in the U.S.

The Centers for Disease Control and Prevention (CDC) has issued a public health advisory noting a significant rise in extensively drug-resistant (XDR) Shigella cases in the United States. According to the CDC, approximately 5% of Shigella cases in 2022 were caused by XDR strains, a notable increase from 0% in 2015 ^[1][2].

Researchers at the University of California, Los Angeles (UCLA) identified a novel XDR strain of Shigella sonnei in three patients in Los Angeles between 2023 and 2024. All patients were men who have sex with men ^[2]. This strain has shown resistance to multiple antibiotics, including azithromycin, ciprofloxacin, ceftriaxone, trimethoprim-sulfamethoxazole, and ampicillin ^[2].

Shigella infections typically result in a self-limiting illness lasting about a week. However, they can occasionally lead to severe or fatal complications, particularly in individuals with weakened immune systems, such as very young children ^[2].

What Is Known

The CDC’s advisory highlights the growing concern over drug-resistant Shigella strains, which have increased significantly since 2015. The identification of a novel XDR strain in Los Angeles underscores the potential for these bacteria to spread and resist standard treatments ^[1][2].

What Remains Unclear

While the presence of XDR Shigella strains in Los Angeles has been confirmed, it remains uncertain whether these strains are actively spreading beyond this region. The assertion that the strain is likely spreading elsewhere in the U.S. is not yet corroborated by multiple sources ^[2].