Legionellosis in a Patient with Water Contamination in Healthcare and Residential Settings: A Case Report

Legionella pneumophila is a waterborne pathogen causing severe pneumonia through inhalation of contaminated aerosols. Data on legionellosis in Indonesia remain limited, particularly regarding environmental sources. To describe a confirmed case of legionellosis and assess potential environmental exposure from hospital and household water systems. Clinical confirmation was performed using PCR detection of L. pneumophila from respiratory specimens. Environmental swab samples were collected from aerosol- and water-associated sources in the hospital and the patient’s home and tested using PCR for Legionella sp. and L. pneumophila. Seven of twelve clinical specimens were positive for L. pneumophila. Environmental sampling detected Legionella sp. in multiple hospital and household sites, although L. pneumophila was not detected. The coexistence of confirmed L. pneumophila infection and environmental Legionella contamination indicates potential dual exposure and highlights the need for strengthened water system surveillance.