1622. Clinical and Environmental Surveillance of Legionella pneumophila in a Tertiary Healthcare Center in India

BACKGROUND: Legionellosis is a form of pneumonia caused by Gram-negative bacilli belonging to the Legionella genus. In India, sporadic cases of legionellosis have been reported, but the incidence of this infection is still believed to be underestimated. We conducted a proactive clinical–environmental surveillance in a tertiary healthcare center to determine the frequency of legionellosis, and to identify the pathogen in the hospital water systems. METHODS: During February 2015–February 2019, we enrolled 533 cases (310 males, 223 females) with a diagnosis of pneumonia; a respiratory secretion was collected from each patient and tested for L.pneumophila by using a real-time PCR targeting mip gene. To identify Legionella spp. present in hospital water systems, we collected 201 hospital water samples and were analyzed by cultivation in BCYE agar. Legionella speciation and identification of Lp1 was done by real-time PCR assay. RESULTS: Among 533 cases, 11(2.1%) [6 male, 5 female] tested positive for L.pneumophila by real-time PCR. Of these, all were community-acquired sporadic cases not associated with a cluster or outbreak. Risk factors including smoking, alcohol use, malignancy, underlying respiratory disease, hypertension were identified in 8 (72.7%) cases. The duration of hospitalization for Legionella patients was 8–24 days; 5/11 (45.5%) patients were admitted to intensive care units. Of 11 patients 8 (72.7%) survived, and 3(27.3%) died. Among the 201 water samples tested, 38 (18.9%) tested positive for L.pneumophila by culture. The presence of Lp1 was detected in 25 (12.4%) water samples. Legionella spp. was recurrently isolated from patient areas, cooling towers, residential areas, and other areas inside the hospital campus. CONCLUSION: The study indicates a low prevalence of legionellosis in this region. Even though Legionella colonization was detected in the hospital water system, no cases of hospital-acquired legionellosis were discovered during the study period. However, considering the risk of nosocomial legionellosis to patients we formulated Legionella control strategies in this hospital. Point-of-use filters were installed to the potable water units from where Legionella was isolated and repeat sampling from these sites were found to be negative for the contagion. DISCLOSURES: All authors: No reported disclosures.