Drug-Resistant Shigella Infections Surge Across the United States, CDC Warns of Growing Public Health Threat

The Centers for Disease Control and Prevention has issued an urgent advisory warning that cases of drug-resistant Shigella infections are rising sharply across the United States, with an increasing proportion of cases now resistant to the frontline antibiotics typically used to treat the illness. The agency has classified the trend as a serious public health threat, raising alarm among infectious disease experts who fear the country may be losing its ability to effectively treat a highly contagious bacterial infection that causes severe diarrhea, fever, and stomach cramps.

Shigellosis, the illness caused by Shigella bacteria, has long been a concern for public health authorities due to the organism’s extraordinary contagiousness. Unlike many foodborne pathogens that require ingestion of large numbers of bacteria to cause illness, Shigella can infect a person with an extremely low infectious dose — sometimes fewer than 100 bacterial cells. The infection spreads through the fecal-oral route, meaning it can be transmitted through contaminated food, water, or surfaces, as well as through direct person-to-person contact. Symptoms typically appear one to two days after exposure and can include watery or bloody diarrhea, abdominal cramps, fever, and nausea, with illness lasting five to seven days. While most healthy adults recover without treatment, severe cases — particularly in young children, the elderly, and immunocompromised individuals — can require hospitalization and antibiotic therapy. It is precisely this need for effective antibiotic treatment that makes the rise of drug-resistant strains so concerning.

The CDC’s surveillance data reveals a troubling acceleration in resistance patterns. Extensively drug-resistant (XDR) Shigella strains — defined as those resistant to all commonly recommended empiric antibiotics — accounted for less than 1% of Shigella infections in 2015 but have risen substantially since then. Between 2015 and 2023, the agency tracked a marked increase in XDR cases, with some strains now resistant to azithromycin, ciprofloxacin, trimethoprim-sulfamethoxazole, ampicillin, and ceftriaxone simultaneously. This leaves clinicians with extremely limited treatment options, sometimes forcing reliance on carbapenems or other last-resort antibiotics that must be administered intravenously in hospital settings — a significant escalation for an infection that was historically manageable with simple oral medications. Infectious disease specialists have noted that this pattern mirrors broader global trends in antimicrobial resistance, which the World Health Organization has identified as one of the top 10 global public health threats facing humanity.

Several factors are driving the rise in drug-resistant Shigella. Overuse and misuse of antibiotics — both in human medicine and agriculture — have created selective pressure that favors the survival of resistant organisms. Shigella bacteria are particularly adept at acquiring resistance genes through horizontal gene transfer, a process by which bacteria share genetic material with one another, including resistance-conferring plasmids. This means that resistance traits can spread not only within Shigella populations but can potentially be transferred to and from other enteric bacteria. International travel also plays a role, as travelers may acquire resistant strains abroad and introduce them into domestic populations. Additionally, outbreaks among specific communities — including daycare centers, homeless shelters, and among men who have sex with men — have been documented, highlighting the importance of targeted public health interventions.

Public health officials are urging healthcare providers to obtain stool cultures and antimicrobial susceptibility testing before prescribing antibiotics for suspected Shigella infections, rather than relying on empiric treatment that may no longer be effective. The CDC is also emphasizing basic hygiene measures as the first line of defense: thorough handwashing with soap and water, especially after using the bathroom and before preparing food; avoiding swallowing water from lakes, ponds, or untreated swimming pools; and staying home from work, school, or daycare while symptomatic. For clinicians, the agency recommends consulting with infectious disease specialists when encountering suspected XDR cases. Looking ahead, public health experts are closely monitoring whether resistance patterns continue to worsen and whether ongoing vaccine development efforts can eventually provide a preventive tool. The trajectory of drug-resistant Shigella will likely serve as a bellwether for the broader antimicrobial resistance crisis that continues to challenge health systems worldwide.