Cruise ship operators are being urged to adopt stricter water testing protocols following recent outbreaks of norovirus and Legionnaires’ disease. The US Centers for Disease Control and Prevention (CDC) has updated its Vessel Sanitation Programme standards, requiring all cruise ships docking at US ports to monitor for Legionella. This marks a significant shift in public health regulations for the cruise industry.

The revised standards, introduced in November 2025, demand comprehensive risk assessments for potable and recreational water systems on ships carrying 13 or more passengers. Operators must define monitoring frequencies, implement remediation protocols, and maintain verifiable records of corrective actions. These changes aim to enhance environmental pathogen control and ensure data-driven performance verification.

Uwe Krüger, joint Managing Director of CM Technologies (CMT), highlighted the importance of these measures, stating, “The revision represents a strengthening of environmental surveillance obligations.” He emphasized the need for strict temperature control, disinfectant management, and circulation stability within water systems to prevent Legionella outbreaks.

David Fuhlbrügger, also a joint Managing Director at CMT, noted that areas such as pools and whirlpools are breeding grounds for bacteria. He stressed the importance of maintaining disinfectant residuals within defined limits and verifying the effectiveness of filtration systems through structured cleaning and documentation.

To aid compliance, CMT offers portable water testing kits for chlorine residuals and bacteria indicators, alongside dedicated Legionella testing kits. These tools enable onboard verification, reducing reliance on periodic laboratory analysis. The CDC will enforce these requirements through port inspections, documentation reviews, and outbreak investigations.