Pseudomonas Infection Outbreak Associated with a Hotel Swimming Pool - Maine, March 2023

Area of Science:

• Public Health
• Environmental Health
• Infectious Disease Epidemiology

Background:

• Hotel pools are a significant source of treated recreational water-associated outbreaks.
• Outbreaks linked to Pseudomonas aeruginosa in these venues often occur during winter months (January-April).

Purpose of the Study:

• To investigate an outbreak of illness linked to a hotel swimming pool.
• To identify the causative agent and contributing factors.
• To inform public health strategies for preventing future outbreaks.

Main Methods:

• An investigation was initiated by the Maine Center for Disease Control and Prevention (Maine CDC) following illness reports.
• A questionnaire was distributed to hotel guests to assess symptoms and exposure.
• Clinical specimens were cultured for bacterial identification, and genetic analysis (single nucleotide polymorphisms) was performed on isolates.

Main Results:

• A significant percentage (66%) of surveyed guests reported symptoms such as ear pain, rash, or extremity pain/swelling after using the hotel pool.
• Pseudomonas aeruginosa was identified in skin lesions of three patients, with genetic similarity suggesting a common source.
• The investigation revealed multiple health code violations at the hotel pool, including the absence of a disinfectant feeder system, noted in a prior inspection.

Conclusions:

• Inadequate pool maintenance and disinfectant levels contributed to the Pseudomonas aeruginosa outbreak.
• Health departments are vital in ensuring hotel pool and hot tub compliance with public health codes.
• Vigilant management, including maintaining chlorine concentration and user education, is essential for preventing recreational water illnesses.