Legionella bacteria detected at Los Angeles County Medical Examiner’s Office

Legionella bacteria, which causes Legionnaires’ disease, was discovered in a cooling system at the Los Angeles County Department of Medical Examiner’s office near downtown Los Angeles. The bacteria was originally detected during maintenance work in May 2026, and employees in the affected buildings were notified later that year.

One county employee has since tested positive for Legionnaires’ disease. While the identity and condition of the worker have not been disclosed, the Los Angeles County Department of Public Health stated that no other cases involving shared exposure to the individual have been identified to date.

Legionnaires’ disease is a serious form of pneumonia. The bacteria typically spreads through the inhalation of contaminated water droplets or mist from building water systems, such as cooling towers, hot water tanks, or plumbing. It is generally not transmitted from person to person.