Contaminated Heater-Cooler Devices

Health Alert

CDC has warned hospitals and patients about the potential risk of Nontuberculous Mycobacteria (NTM) infections from certain heater-cooler devices used during open heart (open-chest) surgery.

Patients who have had open-heart surgery and are having symptoms should seek medical care. While risk of infection is low, it is important to consult with your doctor.

Watch for Symptoms

Patients who have had open heart surgery should seek medical care if they are experiencing symptoms such as

  • night sweats
  • muscle aches
  • unexplained weight loss
  • fatigue
  • unexplained fever

Risk Information

This advice follows information indicating that some LivaNova PLC (formerly Sorin Group Deutschland GmbH) Stöckert 3T heater-cooler devices, used during many open heart surgeries, might have been contaminated during manufacturing which could put patients at risk for life-threatening infections.

More than 250,000 heart bypass procedures using heater-cooler devices are performed in the United States every year, and in approximately 60% of these procedures the devices that have been associated with these infections were utilized. Heater-cooler units are an essential part of these life-saving surgeries because they help keep a patient’s circulating blood and organs at a specific temperature during the procedure.

CDC estimates that in hospitals where at least one infection has been identified, the risk of a patient getting an infection from the bacteria was between about 1 in 100 and 1 in 1,000. While these infections can be severe, and some patients in this investigation have died, it is unclear whether the infection was a direct cause of death. Available information suggests that patients who had valves or prosthetic products implanted are at higher risk of these infections.

Heater-Cooler Notification Toolkit

CDC is available to assist with the process of developing documents for notifications.

Notification information to customize and share:

Patient and physician notification letters to customize:

Patient Q&A

What is the risk of infection?
Overall, the risk is thought to be very low. In hospitals where at least one infection has been identified, the risk of infection was between about 1 in 100 and 1 in 1,000 patients. Initial information suggests that patients who had prosthetic implants are at higher risk. It is possible that not all of the devices introduced these bacteria into the operating room or exposed patients.

How long does it usually take for these infections to show up?
Nontuberculous mycobacteria (NTM) are slow-growing bacteria and infections may take months to develop. Cases associated with this device have been diagnosed within months and up to several years after an open-heart surgery involving heater-cooler unit exposure.

Can a person who develops one of these NTM infections spread it to others, such as family members?
No, the bacteria cannot be spread to others from an infected patient. Also, it is important to keep in mind that NTM is common in soil and water but rarely makes healthy people sick.

Should everyone who was exposed to these devices during open-heart surgery receive antibiotics just in case?
The risk that patients will develop an infection following exposure to a contaminated heater-cooler unit is very low. There is also no evidence that giving antibiotics just prior or during surgery with a potentially contaminated heater-cooler device will prevent infection. Although antibiotics can be life-saving drugs, there is no antibiotic treatment available to ward off this specific infection and antibiotics are also not without risk themselves. Antibiotics put patients at risk for allergic reactions and a potentially deadly diarrheal infection caused by the bacteria Clostridioides difficile. Antibiotic use is also a key driver of antibiotic resistance, which can put patients at risk for antibiotic-resistant infections later.

How long does it take to find out if an infection is being caused by NTM?
M. chimaera is a slow-growing species of NTM The bacteria that causes infection (M. chimaera) is slow growing and can take 8 weeks or more to grow in the lab before final identification.

Why are these infections so deadly?
Symptoms of infection can take months to develop, and are often general and nonspecific. As a result, diagnosis of these infections can be missed or delayed, sometimes for years, making these infections more difficult to treat. Clinicians may not immediately consider an NTM diagnosis. Delayed diagnosis can result in more widespread disease in a patient. This, combined with underlying health problems such as heart disease can make these infections difficult to treat.

How do you think the devices got contaminated?
Recent CDC findings are consistent with previous reports suggesting that the heater-cooler units were contaminated during production. Testing conducted by the manufacturer in August of 2014 found M. chimaera contamination on the production line and water supply at the manufacturing facility.

Have these devices ever been recalled? Why aren’t they being recalled now?
In 2015, the manufacturer recalled the instructions for use, but not the device itself. Information provided by the manufacturer reminded users that while water from the device itself is not intended to contact the patient directly, under certain circumstances, due to fluid leakage and/or aerosolization, NTM could reach a patient’s surgical site. Heater-cooler devices are critical for life-saving surgery.

Hospital & Health Department Case Tracking Q&A

CDC’s October 2016 Health Alert advises health departments to track reports from healthcare facilities about potential infections associated with heater-cooler devices. What information should be collected about these infections? Should infections be reported to the CDC?
Health departments should consider collecting information from healthcare facilities on any patients with invasive nontuberculous mycobacteria (NTM) infections following cardiac surgery with exposure to heater-cooler devices. Invasive NTM infection refers to an NTM-positive specimen from a normally sterile body site (such as blood, bone marrow, bone, spinal fluid, abdominal or pleural fluid), from skin, soft tissue, or drainage from a wound or abscess, or from lymph nodes. Data elements about patients with NTM infection that may be useful to obtain include:

  • demographics (e.g., age, sex, county/state of residence)
  • diagnosis (e.g., type and location of NTM-positive specimen, NTM species, date of positive culture, date of symptom onset, clinical manifestation)
  • exposure history (e.g., date of surgery with heater-cooler device exposure, type of surgical procedure, hospital where surgery was performed, heater-cooler device make/model/year of manufacture, implantation of prosthetic device during surgery, any risk mitigation strategies utilized in the hospital, such as moving the device outside of the operating room, if heater-cooler device has tested positive for NTM)
  • outcome (e.g., death, treatment success or failure)

Health departments should encourage hospitals to report all cases to the FDA

Hospitals should strongly consider reporting infections to the NTM registry, which will help researchers and clinicians, learn more about diagnostic, treatment and outcome information for patients. Reporting of infections to CDC is voluntary. Health departments can email  questions regarding heater-cooler device-associated infections (without patient identifying information) to CDC at Health departments may wish to review CDC Response and Outbreak Consultation Guidance [PDF – 218 KB].

Hospital Patient Notification Q&A

How far back in time should hospitals go to notify patients?
Hospitals should consider notifying patients in writing if they were exposed to the Stöckert 3T devices during open-chest cardiac surgery after January 1, 2012. Hospitals that did not use the Stöckert 3T device during this entire time period should adjust the patient notification timeframe accordingly.

What is the rationale for active patient outreach? Why use this time frame?
Based on our current understanding, the majority of patients who become infected from exposure to these devices will develop symptoms within months of their exposure. Pursuing active patient outreach using a longer time frame of approximately 4 years is expected to benefit most of the patients who have developed symptoms but have not yet been diagnosed. However, any patient who has had cardiac surgery with the Stöckert 3T device – including patients who had their surgery prior to 2012 – should be aware of this risk in the event that they develop concerning symptoms. Other forms of patient outreach (e.g., through advocacy channels or the media) will be helpful in this regard. Likewise, ongoing efforts to raise awareness among clinicians is expected to benefit all patients, regardless of when their exposure occurred.

Our hospital acquired a Stöckert 3T device after September 2014.  Should we still notify patients?
Yes. Patients who were exposed to Stöckert 3T devices manufactured after September 2014 should also be notified. While the risks associated with these newer devices may be lower, some have tested positive for M. chimaera (see FDA investigation summary), possibly as a result of cross contamination from accessory devices.

Our hospital conducted retrospective case-finding and we did not identify any probable cases – do we still need to send patient letters?
Yes, while case finding is important, negative results cannot be relied upon to determine an absence of risk.

Our hospital conducted retrospective case-finding and we identified a probable case that had surgery before January 1, 2012. Do we need to extend the time period of our notification?
Decisions to extend notification farther back in time using individualized patient letters may best be considered on an institution-specific basis. The likelihood of identifying undetected infections diminishes with time. However, directly notifying individual patients who have been identified as having actually acquired an infection from a contaminated heater cooler device is advisable regardless of when the exposure occurred.

Are only patients who have had prosthetic material implanted during their cardiac surgery at risk for M. chimaera infections? Should our hospital only notify patients who have had prosthetic material implanted?
Although there is some evidence that patients who have prosthetic material implanted during their open-chest cardiac procedure may be at higher risk of developing infection, heater-cooler device associated NTM infections have also occurred among patients who did not have placement of prosthetic material. Therefore, hospitals should not determine which patients to notify based on whether they have had the placement of prosthetic material during their procedures.

In 2015, our hospital took measures to mitigate risk to patients by following updated manufacturer’s recommendations for disinfection and cleaning and updated guidance from the FDA. Do we still need to notify patients?
Yes, hospitals should still notify patients. A possible exception pertains to hospitals that have taken additional steps (e.g., moved the Stöckert 3T device out of the operating room) to eliminate patient exposure to the exhaust from these devices. These hospitals may consider not notifying patients who had surgery after these interventions if they are confident that the risk was abated.

The Stöckert 3T devices at our hospital tested negative for M. chimaera. Should we still notify patients?
Yes, hospitals should still notify patients. In general, methods for sampling and microbiological testing of heater-cooler devices for M. chimaera are neither reliable nor timely. Therefore, negative test results do not necessarily indicate that devices are not presently contaminated or that they have not been contaminated in the past.

How do I diagnose a patient with M. chimaera infection? How do I treat a patient with an M. chimaera infection?
Initial experience from clinicians indicates that these infections can be challenging to diagnose and treat. Patients have presented with a variety of clinical manifestations including endocarditis, surgical site infection, or abscess and bacteremia. Other clinical manifestations have included hepatitis, renal insufficiency, splenomegaly, pancytopenia, and osteomyelitis.  Patients have also presented with granulomatous disease and have been misdiagnosed with sarcoidosis. CDC recommends that physicians consult with an infectious disease specialist for specific clinical concerns regarding these infections. CDC hosted Invasive NTM Infections and Heater-Cooler Units Training which included a presentation by clinical experts on the diagnosis and treatment of M. chimaera infections.

Updated Device Information from FDA