More than half a million patients who had open-heart surgery in the United States since 2012 could be at risk for a deadly bacterial infection linked to a device used during their operations, federal health officials said on Thursday.
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 they help keep a patient’s circulating blood and organs 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 typically aren’t 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.
During the past year, the Centers for Disease Control and Prevention and the Food and Drug Administration have notified hospitals and doctors about the potential linkage between the machines and infection. But recently completed genetic fingerprinting has provided the strongest evidence so far that the machines were contaminated at a single source — during their production in Germany. That means many more machines could be contaminated with the bacteria than have been identified so far, placing thousands more patients at risk.
Federal officials want to raise awareness of the issue among doctors and patients. “Although thousands of patients in the United States have been notified regarding potential exposure to contaminated heater-cooler devices, the number who were exposed might be much larger,” according to a Thursday CDC report.