Although rare, such infections may cause serious illness or death. The infection is particularly insidious because it is difficult to detect. Patients may not develop symptoms or signs for months after initial exposure.
In just the past year, at least 28 cases have been identified, with hospitals in Iowa, Michigan and Pennsylvania reporting infections. Numerous infections also have been reported in patients in Europe; some were diagnosed almost four years after surgery.
The device in question is a piece of medical equipment known as a heater-cooler unit, an essential part of life-saving surgeries because it helps keep a patient’s organs and circulating blood at a specific temperature during the operation. It is used in an estimated 250,000 heart-bypass procedures in the United States every year. About 60 percent of these procedures use the German-made model that has been linked to the infections.
The bacteria, known as nontuberculous mycobacterium, or NTM, are commonly found in nature and aren’t typically harmful. But NTM can cause infections in patients who have had invasive procedures, especially when they have weakened immune systems.
Symptoms of infection are often general, such as night sweats, muscle aches, weight loss, fatigue or unexplained fever. As a result, diagnosis can be missed or delayed, making the infection more difficult to treat. Treatment involves a specific antibiotic combination because routine antibiotics won’t be effective against the slow-growing germ.
Federal officials want to raise awareness of the issue among doctors and patients.
To date, eight hospitals in four states have notified about 15,000 of their patients who underwent an open-chest procedure, in some cases going back to 2011.
WellSpan York Hospital in York, PA was the first hospital in the country to identify a cluster of NTM infections in July 2015. Hospital staff, working with the CDC and the Pennsylvania health department, reviewed all the facility’s open-heart surgery cases and sent letters to about 1,300 patients who many have been exposed going back four years.
The Stöckert 3T heater-cooler devices have been available in the United States since 2006, according to the FDA. The manufacturer is LivaNova PLC, formerly Sorin Group Deutschland GmbH. The FDA estimates there are close to 2,000 devices in the United States.
The company has received complaints about patient deaths related to NTM infections and the devices since January 2014, according to the FDA.
These are the six hospitals that have reported infections in Pennsylvania, Iowa and Michigan, the number of at-risk patients who were notified, the number of patients identified with NTM infections, and the dates of surgery:
- WellSpan York Hospital – 1,300 notified; 12 cases; 10/1/11 to 7/24/15
- Penn State Hershey Hospital – 2,300 notified; 5 cases; 11/5/11 to 11/5/15
- Penn Presbyterian Medical Center – 1,100 notified; 4 cases; 10/1/13 to 12/17/15
- University of Iowa – 1,500 notified; 3 cases; 1/1/12 to 1/22/16
- Mercy Medical Center in Iowa – 2,600 notified; 2 cases; 7/1/12 to 7/1/16
- Spectrum Health Medical Center in Michigan – 4,500 notified; 2 cases; 1/1/12 to 11/10/15