Transplanted lungs likely spread dangerous Legionella infection to two recipients, study says

For the first time, an organ transplant is believed to have spread dangerous Legionella bacteria, according to a report published Thursday by the US Centers for Disease Control and Prevention.

The two people who developed Legionnaires’ disease received donated lungs from a man who died last year after falling into a river in Pennsylvania. The man, who was in his 30s, had been declared brain-dead after attempts to resuscitate him were unsuccessful.

Doctors were able to transplant his right lung into a woman in her 70s. His left lung went to a man in his 60s. Both eventually developed Legionnaires’, a severe form of pneumonia caused by the Legionella bacteria.

People who receive transplanted organ are particularly vulnerable to infections because they have to take a medicine that suppresses their immune system for the rest of their lives to keep it from attacking the donor organ.

In this case, the female patient became ill and tested positive for the Legionella species of bacteria in June 2022, about a month after she received the lung transplant. Doctors treated her with an antibiotic, and she fully recovered.

The male patient had several complications after the transplant and tested positive for the bacteria in June. He initially appeared to recover but died about six months after the transplant surgery due to respiratory failure.

Doctors tested three other people who received organs from the same donor, but they remained free of the bacteria.

After learning about the infections, the Pennsylvania Department of Health went on the hunt for the source of the bacteria.

The department tested the water at the hospital where the transplant operations were done but did not find any evidence of Legionella. Eventually, officials began to suspect that the bacteria came from the drowned organ donor, since Legionella bacteria can be found naturally in fresh water. It’s possible that when the man inhaled the water, he picked up the bacteria.

The CDC warns that instances of Legionnaires’ disease have increased “substantially” over the past decade. The bacteria thrives in warm water, and as the climate crisis has increased temperatures, there have been many more opportunities for it to grow.

Scientists hope the new report will serve as a warning to health care providers to be on the lookout for potential Legionella infections in organ recipients.

“This cluster highlights the need for increased clinical awareness of possible infection with Legionella in recipients of lungs from donors who drowned in fresh water before organ recovery,” says the study, from researchers in Pennsylvania and at the CDC. “Prompt diagnosis and treatment of Legionnaires disease increases the likelihood of a full recovery.”