Surveillance of Legionella spp. in water supply of Hotel in Phuket fiscal year 2022

Abstract

This study aims to monitor the contamination of Legionella spp. in water supply system in hotels in Phuket province during the fiscal year 2023. The sampling involved water and swab samples collected from 15 hotels during the period from June to August 2023. The collected samples were analyzed using the culture method referenced from the Centers for Disease Control and Prevention (CDC) in 2005. The results revealed Legionella spp. in 2 out of the 15 hotels, with a contamination rate of 13.33%. This indicates a potential risk of Legionella spp. contamination in the hotel water supply systems. Further analysis showed that 2 hotels had contamination levels below 10⁵ CFU/L, suggesting a low level of contamination. However, these still require monitoring and management. The specific strains identified through Latex agglutination were Legionella pneumophila serogroup 1 and Legionella pneumophila serogroups 2-14. The test results were communicated to the hotels, and recommendations were provided for improving their water systems, including measures for disinfected the detected Legionella spp. contamination. Subsequent to the implementation of water system improvements in the two hotels with initial contamination, a second round of sampling was conducted. The results of the second analysis revealed no presence of Legionella spp. in either of the two hotels. The information obtained from this study is beneficial for hotel operators to enhance and maintain their water systems in accordance with the health department's guidelines, ensuring the safety of tourists and guests staying in hotels.