Atlanta—Antibiotics typically used to treat more problematic cases of shigellosis are often not working well anymore, leading the CDC to issue a health alert about an increase in extensively drug–resistant (XDR) Shigella infection.

The alert points out that in 2022, about 5% of Shigella infections reported to the CDC were caused by XDR strains, compared with 0% in 2015. The result is that clinicians treating patients infected with XDR strains have limited antimicrobial treatment options.

“Shigella bacteria are easily transmissible. XDR Shigella strains can spread antimicrobial resistance genes to other enteric bacteria,” the CDC advises, saying that is why it is asking healthcare professionals to be vigilant about suspecting and reporting cases of XDR Shigella infection to their local or state health department and educating patients and communities at increased risk about prevention and transmission.

An important cause of domestically acquired and travel-associated bacterial diarrhea in the United States, shigellosis is an acute enteric infection that usually causes inflammatory, often bloody diarrhea, and might also involve fever, abdominal cramping, and tenesmus.

While infections are usually self-limiting, antimicrobial treatment is used in some cases to prevent complications or shorten the duration of illness. XDR Shigella is defined by the CDC as strains that are resistant to all commonly recommended empiric and alternative antibiotics—azithromycin, ciprofloxacin, ceftriaxone, trimethoprim-sulfamethoxazole (TMP-SMX), and ampicillin. At this point, CDC is making no recommendations for optimal antimicrobial treatment of XDR Shigella infections.

Complicating matters is that shigellosis traditionally has been an infection that affected young children (aged 1-4 years) in the United States. The CDC says it is now seeing more cases in adult patients, especially in gay, bisexual, and other men who have sex with men (MSM); the homeless; international travelers; and HIV patients.

Antibiotics have been used to shorten the duration of illness (by about 2 days) or to reduce the likelihood of transmission, such as:

• During outbreaks
• In institutional settings
• From food handlers
• To immunocompromised persons or those being treated with immunosuppressive drugs
• To people living with HIV.

The CDC states that in the United States, recommended empiric antimicrobial agents include azithromycin, ciprofloxacin, or ceftriaxone. Alternative treatments for susceptible strains have been ampicillin or TMP-SMX.

Public health officials recommend that pharmacists and other healthcare professionals advise patients with shigellosis to stay home from school or healthcare, food service, or childcare jobs while sick or until the health department says it is safe to return.

In addition, during diarrhea and for 2 weeks after it ends, patients should:

• Abstain from all types of sex
• Wash hands often
• Refrain from preparing food for others
• Stay out of recreational water, including swimming pools, hot tubs, water playgrounds, oceans, lakes, and rivers.

The content contained in this article is for informational purposes only. The content is not intended to be a substitute for professional advice. Reliance on any information provided in this article is solely at your own risk.

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