Deadly Drug-Resistant Bacteria Spreading on Cruise Ships

CDC warns of rising cases of XDR Shigella causing bloody diarrhea outbreaks

Apr. 17, 2026 at 12:25pm

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An extreme close-up X-ray photograph revealing the intricate internal structures of a cruise ship's ventilation system, conceptually representing the hidden spread of drug-resistant bacteria.An X-ray view exposes the unseen spread of antibiotic-resistant bacteria through a cruise ship's ventilation system, posing a growing public health threat.Today in Jacksonville

Federal health officials are sounding the alarm about a dangerous strain of drug-resistant bacteria causing bloody diarrhea outbreaks on cruise ships. The Centers for Disease Control and Prevention (CDC) has reported a growing proportion of cases since 2015 linked to extensively drug-resistant (XDR) Shigella bacteria, which are resistant to multiple antibiotics.

Why it matters

Shigella infections can be life-threatening, especially for vulnerable populations like the elderly and immunocompromised. The rise of XDR Shigella strains makes these outbreaks much harder to treat, posing a serious public health threat for the cruise industry and passengers.

The details

The CDC's Vessel Sanitation Program inspects cruise ships in U.S. ports, requiring a minimum score of 86 to pass. However, the agency has seen a concerning increase in XDR Shigella cases, defined as being resistant to ampicillin, azithromycin, ceftriaxone, ciprofloxacin, and trimethoprim-sulfamethoxazole.

  • The CDC has reported a growing proportion of XDR Shigella cases since 2015.

The players

Centers for Disease Control and Prevention (CDC)

The U.S. federal health agency responsible for protecting public health and safety through the control and prevention of disease, injury, and disability.

Vessel Sanitation Program

A CDC program that inspects cruise ships in U.S. ports, requiring a minimum score of 86 to pass.

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The takeaway

This outbreak highlights the growing threat of antibiotic-resistant bacteria and the need for improved sanitation and infection control measures on cruise ships to protect passenger health and safety.