In facilities with decorative water features like open water walls, which organism should be routinely monitored?

• A. Campylobacter jejuni
• B. Legionella pneumophila
• C. Clostridioides difficile
• D. Norovirus

Answer: (B)

In decorative water features, the main risk comes from inhaling aerosols that may contain Legionella pneumophila. This organism thrives in warm, stagnant or poorly circulated water and can form biofilms in water systems, including open water walls and fountains. When these features aerosolize tiny droplets, people can inhale them and develop Legionnaires’ disease or a milder Pontiac fever. Because of this specific risk, facilities routinely monitor Legionella to detect colonization early and implement controls such as maintaining appropriate temperatures, ensuring proper disinfectant residuals, and regular cleaning and flushing of the system.

Campylobacter jejuni is primarily a food- or waterborne pathogen associated with contaminated food or unpasteurized liquids, not typically linked to decorative water features. Norovirus spreads through contaminated food or person-to-person contact and is not the typical concern for aerosol exposure from decorative waters. Clostridioides difficile is a healthcare-associated organism spread by spores in patient care environments, not by decorative water features. Thus, Legionella is the best answer for routine monitoring in this context.