Center for Heart & Vascular Health

M. chimaera Patient Information

Important follow-up information for the patients who may have been exposed to M. chimaera during open-heart surgery at Christiana Hospital from Jan. 1, 2012 to Sep. 30, 2016.

We want to make sure you get all the information, care and treatment you may need related to this issue. The U.S. Centers for Disease Control and Prevention and the U.S. Food and Drug Administration have notified all hospitals, including Christiana Care, of a potential exposure to bacteria in patients who have undergone open-heart cardiac surgery using a heart/lung bypass machine. The bacteria have been linked to devices that regulate blood temperature used during these surgical procedures. The bacterium is called M. chimaera. It is a common bacterium found in soil and drinking water. It normally is not harmful to humans and only rarely has caused infections in patients with weakened immune systems. However, patients who have had open-chest heart surgery may have become exposed to these bacteria during their procedure, and could be at risk of infection.

If you have questions, please call our Patient Relations team at 302-733-1340. If you have any concerning new or worsening symptoms please contact your doctor.

We are committed to answering any questions and addressing any concerns you may have as the safety of our patients at Christiana Care is our top priority. It is a privilege to serve you and we thank you for choosing Christiana Care for your health needs.

For the latest information about the M. chimaera situation, please visit the Centers for Disease Control and Prevention (CDC).

Below is information we have provided to patients about the situation, and are including as a reference.

Frequently Asked Questions: Mycobacterium chimaera

General Outbreak Information

What is the situation?
The U.S. Centers for Disease Control and Prevention and the U.S. Food and Drug Administration have notified all hospitals, including Christiana Care, of potential exposure to a certain bacteria in patients who have undergone open-heart cardiac surgery using a heart/lung bypass machine. The bacteria have been linked to devices that regulate blood temperature used during these surgical procedures.

What type of bacteria is involved?
The bacterium is called Mycobacterium chimaera or M. chimaera. It is a common bacterium found in soil and drinking water. It normally is not harmful to humans and only rarely has caused infections in patients with weakened immune systems. However, patients who have had open-chest heart surgery may have become exposed to these bacteria during their procedure, and could be at risk of infection.

What is a heater-cooler device and how might it be related to this problem?
A heater-cooler device is routinely used during open-heart surgeries to warm or cool a patient’s blood. The device is never in direct contact with the patient or the patient’s blood. However, bacteria may be carried from the water tank within the device into the air through the device’s exhaust vent. The bacteria in the air can then come into contact with a patient through their open wound during surgery.

Has this happened at other hospitals?
Yes. Multiple cases have been documented in the United States and throughout the world. In the United States, the CDC and the FDA have issued health advisories to hospitals to help them prevent and detect these infections. We are following these recommendations.

How Christiana Care Has Responded

What is Christiana Care doing about this?
Following CDC and FDA recommendations, we have been actively working to identify and alert those patients who may have been exposed to M. chimaera at Christiana Care. Our Infection Prevention team has been actively monitoring this situation. The team has analyzed lab results for suspect infection diagnoses, such as mycobacterial cultures and sarcoidosis, and then compared them to the records of patients who underwent open-heart surgery at Christiana Care during the time period of January 1, 2012 to September 30, 2016, in which these heater-cooler devices were used.

We have identified several patient cases with  M. chimaera, which were probably linked to the heater-cooler devices used during their surgeries. These patients presented with several weeks of symptoms and were found to have heart-valve infections. Their blood cultures grew M. chimaera. Since identifying the first case, we have worked with the Delaware Division of Public Health and the CDC on the appropriate response, and reported the cases to the FDA. In addition, our clinical engineering team made significant improvements to the surgical devices to reduce the risk of aerosolization and protect the safety of our patients, until new devices could be obtained. As of February 2017, the new heater-cooler devices (from a different manufacturer) are in place.

Why doesn’t my doctor know about this?
We are providing ongoing information and updates to our entire Medical Dental staff.  We have also begun to alert all providers whenever a patient who underwent cardiac surgery between January 2012 and September 2016 enters the health system, to remind them to screen patients for symptoms and order appropriate testing, if needed.

If this was known in October 2015 (first FDA alert), why am I only being contacted now?
Throughout this situation we have responded to new information as it became available.  In summer/fall of 2015 it was first identified that heater-cooler units could spread infection in this way, but it was initially believed that contamination of the devices occurred at individual hospitals.  “It was not reported until spring of 2016 that these devices may have become contaminated at the Sorin factory in Germany. It was not until fall of 2016 that we confirmed two cases as having M. chimaera, at which point we immediately began the process of notifying all patients who had been exposed to these devices.

I want my blood work checked more than one time, will Christiana Care allow that?
In cases that have been described who had >1 culture obtained, if 1 was positive they were all positive.  So we believe that obtaining 1 mycobacterial culture will allow us to evaluate whether or not you have disease.  Repeated testing may be necessary if symptoms continue.  Of course, if your symptoms change or worsen at any time, you should be re-evaluated, not only for M. chimaera but for other problems as well.

 I want to see another provider, how do I do that and avoid a bill?
We can arrange for direct billing for those patients who would prefer to see their own PCP or another provider.

What Is My Risk?

What types of surgeries placed patients at risk for this infection?
Heater-cooler devices are typically used for open-heart surgeries – such as coronary artery bypass grafting (CABG) or valve replacements.  Any cardiac procedure done in the catheterization lab rather than the operating room (OR) was not affected.

What if I had another type of heart surgery?
Patients who had other, less invasive heart procedures – such as stents, pacemakers, defibrillators and ablations – or minimally invasive cardiac surgery procedures such as transcatheter aortic valve replacement (TAVR), are at minimal because the heater-cooler device is not used for these procedures. In some cases, the device may have been in operation prior to the surgery, but turned off before the patient enters the operating room. However, we have reviewed our past and current procedures and feel that it is unlikely that the equipment used was contaminated.

What if I had heart surgery before January 1, 2012?
Christiana Care first purchased the heater-cooler devices in question in 2008, so patients who had open-heart surgery between 2008 and 2012 may have been exposed.  However, it is unlikely that an exposed person would not have developed significant symptoms more than 4 years after surgery, and remain undetected.  For that reason, CDC and FDA both advise notifying patients for potential screening going back to January 2012.  However, if you feel that you have symptoms consistent with M. chimaera and may need screening, please call our Patient Relations department at 302-733-1340 to make arrangements.

What are my chances of having this infection?
According to the CDC, the risk of infection is very low.

Can I find out whether I’m infected?
If you do not have symptoms, you do not require testing.  It is unclear that the testing would be useful in an early asymptomatic stage.  Because the bacterium grows slowly, it can take several months or years for symptoms of infection to develop. If you have or develop symptoms, it is important for your physician to know in order to arrange testing.

If I don’t have symptoms now, does that mean I’m okay?
M. chimaera infections can take a long time to develop and cause symptoms. This means that even if you don’t have symptoms now, you could still develop them in the future. So it is important to monitor your health and to let your primary care provider and/or cardiologist know if you do develop symptoms of M. chimaera that last more than 2 weeks in the future.  If it has been more than 4 years since your surgery, it is highly unlikely that you were infected.

I previously was evaluated for M. chimaera infection and my blood culture was negative? Am I still at risk?
It is reassuring that a blood culture was negative, and your overall risk is very low.  However, depending on your situation you may need to monitor your health, and seek re-testing.  It is not clear whether one or more blood cultures, done at a specific moment in time, will always pick up M. chimaera.  This may be particularly true if your surgery was relatively recent or if you have no, or very mild, symptoms.  If symptoms worsen, or new symptoms develop, it would probably be best to be re-tested.  If it has been at least 4 years from the date of your surgery and your cultures were negative, then you can be reassured that you were not infected.

What do I need to do now?
Please call Patient Relations at 302-733-1340 if you have any concerns
. If necessary, we can arrange further screening with a medical provider. You will not be charged for this appointment.

Clinical Syndrome

What are the symptoms of a M. chimaera infection?
Symptoms include the following:

  • night sweats
  • muscle aches
  • weight loss
  • fatigue
  • fever
  • joint pains

These symptoms are not specific for M. chimaera and can be due to many other causes, but M. chimaera should be considered if you had possible exposure from open-heart surgery, and have any of the above symptoms without another known cause.  In addition, other physical findings or laboratory abnormalities, such as low blood counts, liver abnormalities, kidney problems, enlarged spleen, enlarged lymph nodes, or wound infections may be seen.

How long does it usually take for these infections to show up?
Mycobacteria are slow-growing 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.

Is this infection treatable?
According to the CDC, the risk of infection is very low, but if you did happen to be infected, there are effective antibiotic treatments available. These infections typically require months of treatment.

If I have been exposed or develop a M. chimaera infection, is my family at risk of getting the infection?
No. This bacterium cannot be spread by person-to-person contact.

What is my risk of death?
Of the initial cases that have been described, about half have died.   However, this is partly due to the fact that there was a delay in their diagnosis and treatment.  This is not a typical bacterium that would be found doing routine testing.  Now that we are notifying patients, know to look for M. chimaera, and identifying the infection earlier, patients’ outcomes should be much better.

Can I start antibiotics now?
Because the risk of infection is low, in most cases we would not recommend starting antibiotics without knowing for certain that you have the infection.  While the antibiotics are generally safe, the risk of side effects is greater than the possible benefit, if we don’t know that you actually have the infection.  If we are highly suspicious of mycobacterial infection based on your initial evaluation, we may refer you to see an Infectious Diseases doctor for evaluation, before your blood culture results are complete.

If my culture is positive what will my treatment be and how long?
Treatment for mycobacterial disease is effective but requires at least 12 months of 2-3 different antibiotics.  Depending on the location of the infection (such as on a heart valve), some patients have required repeat surgery to clear the infection.  Most however only require antibiotics.