LEGIONELLA WATER SURVEILLANCE IN SOUTHEASTERN TURKIYE:A FIVE-YEAR EPIDEMIOLOGICAL EVALUATION

Abstract

Legionella is a waterborne Gram-negative bacterium transmitted mainly through inhalation of contaminated aerosol from artificial water systems, such as those found in healthcare facilities and hotels.  In this study we aimed to determine the prevalence and temporal trends of Legionella in hospitals and hotels in southeastern Türkiye in order to inform prevention strategies at these study sites.  Water samples were collected from hot- and cold-water systems from study sites and sent for culture and filtration with acid treatment in order to detect Legionella spp from January 2019 to December 2023.  Water samples were collected from faucets, shower heads, storage reservoirs, hot and cold-water tanks and were processed within 24 hours of collection.  A total of 67 hospitals and 7 hotels were purposively selected for the study.   A total of 7,112 water samples were collected and included in the study; 6,934 (97.4%) from hospitals and 178 (2.6%) from hotels.  Of these, 624 samples (8.8%) were positive for Legionella spp; 596 (95.5%), from hospitals and 28 samples (4.5%) from hotels (p-value<0.001).  The most common sites with positive specimens were from faucets (n = 327, 52.4%) and shower heads (n = 182, 29.2%).  430 samples (68.9%) were positive for serogroups 2-14 and 182 samples (29.2%) were positive for serogroup 1  (p-value<0.001).  The mean bacterial concentration among positive study samples was relatively low (52 CFU/ml).  The numbers of positive samples during the Spring, Summer, Winter and Autumn were 130 (20.8%), 205 (32.9%), 111 (17.8%) and 178 (28.5%) samples, respectively (p-value<0.001).  In summary, Legionella contamination was widespread in healthcare water systems in Southeast Türkiye with the most common serogroups being L. pneumophila serogroups 2–14.  Conclusion, there is a need for improved water management and continuous surveillance at the study sites to reduce the risk of contracting Legionella infection at the study institutions.  After implementing these prevention measures further studies are needed to determine their efficacy.