The airborne bacteria that causes deadly Legionnaires’ disease was discovered at the Los Angeles County Medical Examiner’s Office, with an employee later testing positive for the disease.

The bacteria, legionella, was detected in a cooling system at the office near downtown LA, according to NBC 4.

The identity of the worker who tested positive the person’s condition remain undisclosed.

Officials have not publicly established whether the employee’s infection was connected to the contaminated system.

“The Los Angeles County Department of Public Health was notified of one Los Angeles County employee who tested positive for Legionnaire’s Disease,” a department spokesperson told NBC.

The discovery dates back to May 2026, when the bacteria was found during maintenance work.

Employees in the affected buildings were notified later in the year, according to officials.

A spokesperson for the Medical Examiner’s office declined to answer questions, referring inquiries to the Department of Public Health.

The county reported no other infections involving people with shared exposure to the employee.

“To date, no additional cases have been identified with shared common exposures to this individual,” officials said.

Legionnaires’ disease is a serious form of pneumonia caused by the Legionella bacteria. People can become infected by breathing in contaminated water droplets or mist, which can originate in cooling equipment and building plumbing systems.

County health officials described the bacteria as “commonly found in building plumbing systems, especially in older buildings.”

The illness can cause fever, chills, headaches, coughing and breathing difficulties. Symptoms generally emerge two to 14 days after exposure, and the US Centers for Disease Control and Prevention says it is usually treatable with antibiotics.

The infection does not typically spread directly between people. Instead, contaminated water systems can release droplets that carry the bacteria into the air.

County officials said healthcare providers must report “symptomatic cases” and that public health authorities monitor high risk settings.