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

Abstract

Treated recreational water venues (e.g., pools and hot tubs) located at hotels represent one third of sources of reported treated recreational water-associated outbreaks; when these outbreaks are caused by Pseudomonas aeruginosa, they predominantly occur during January-April. On March 8, 2023, the Maine Center for Disease Control and Prevention (Maine CDC) initiated an investigation in response to reports of illness among persons who had used a swimming pool at hotel A during March 4-5. A questionnaire was distributed to guests who were at hotel A during March 1-7. Among 35 guests who responded, 23 (66%) developed ear pain, rash, or pain or swelling in feet or hands within days of using the pool during March 4-5. P. aeruginosa, a chlorine-susceptible bacterium, was identified in cultures obtained from skin lesions of three patients; a difference of two single nucleotide polymorphisms was found between isolates from two patients' specimens, suggesting a common exposure. Hotel A management voluntarily closed the pool, and Maine CDC's Health Inspection Program identified multiple violations, including having no disinfectant feeder system, all of which had been identified during a previous inspection. Because chlorine had been added to the pool water after the pool was voluntary closed, environmental samples were not collected. The pool remained closed until violations were addressed. Health departments can play an important role in reducing the risk for outbreaks associated with hotel pools and hot tubs. This reduction in risk can be achieved by collaborating with operators to ensure compliance with public health codes, including maintaining chlorine concentration and otherwise vigilantly managing the pool, and by disseminating prevention messages to pool and hot tub users.

FIGURE 1

Identification of guests who used the pool at hotel A — Maine, March 4–5, 2023^,† Abbreviation: Maine CDC = Maine Center for Disease Control and Prevention. “Additional registrations” are registration records for guests not previously identified; records did not include the total number of guests per registration. ^† The survey questionnaire was not distributed to two of the 29 hotel A registrants; these two guests booked through a third-party website and did not input a telephone number or email address.

FIGURE 2

Identified cases of Pseudomonas infection, by dates of illness onset and hotel swimming pool use (n = 20)— Maine, March 2023 Abbreviation: Maine CDC = Maine Center for Disease Control and Prevention. * Illness onset date not available for three pool users with reported illness.