Should I be worried about an infection risk following heart valve surgery?

A team of surgeons performing a heart transplant

I had a heart valve replacement in February 2016. In March 2017 I received a letter warning that I might be at risk of infection as a result of the surgery. Should I be worried?

Dr Mike Knapton explains:

If you, or your child, have had open heart surgery, a heart transplant or lung transplant since January 2013, there's a very small risk that you may have been infected with bacteria called Mycobacterium chimaera. This problem is a world-wide issue and in the UK the healthcare regulatory agencies issued guidance to surgical centres in November 2015 after Mycobacterium chimaera infection risk was identified. This guidance was updated in February 2017.

The risk of infection has been linked to a device used to heat and cool the blood during some types of heart surgery, when the patient is connected to the heart/lung bypass machine. This is a rare but potentially serious complication, so the infection needs to be identified to allow your specialist to advise on the appropriate treatment.

In spring 2017, your hospital will have sent you a letter, following your heart valve surgery, explaining the risks and what to do. Other at-risk groups include heart or lung transplants.

No cases of the infection have been identified in patients who had surgery since January 2015, but the situation is being monitored closely.

Who is at risk of Mycobacterium chimaera infection?  

Anyone who has had open heart surgery including heart or lung transplantation since January 2013 could be at risk, including people who had their operation outside the UK. This is particularly true of valve surgery patients.

How worried should I be?

Not too worried. The risk of developing the infection is extremely low - estimated at 1 in 5000 patients who had heart valve surgery and even lower for other types of surgery.

What should I do next?

The only thing you need to do is to tell your GP when you next visit them and make sure that the details of the surgery that you had are included in your medical records.

The risk of developing the infection is extremely low

Can I get tested for the Mycobacterium chimaera infection?

There is no test to predict whether or not you will get this infection. Testing can only be done if someone has symptoms. It is important that people are aware of these symptoms although unfortunately these are non-specific and can take a long time (maybe even several years) to appear.

What are the symptoms?

Symptoms of Mycobacterium chimaera infection include:

  • a fever – including feeling hot and shivery or having a temperature of 38C (100.4F) or above 
  • unexplained weight loss 
  • cough or increasing shortness of breath 
  • waking up with bed sheets showing signs of sweating (night sweats)
  • joint or muscle pain 
  • feeling sick or vomiting 
  • feeling unusually tired 
  • pain, redness, warmth or pus around where you had your operation.

It is important to see your GP if you experience any of these symptoms.

Patients with concerns are encouraged to discuss them with their surgeon or care team

There's no need to seek emergency treatment, as these symptoms can have many different causes and are very unlikely to be due to a Mycobacterium chimaera infection. If you are diagnosed, a specialist heart and infection team would come together to decide on a treatment plan. 

What about people who are due to have surgery? 

Extra measures have been put in place to reduce the risk, although as with any surgery it’s impossible to remove the risk of infection completely. The risk of contracting an infection is far lower than the risk of delaying life saving cardiac surgery, but patients with concerns are encouraged to discuss them with their surgeon or care team.

Can I catch this infection from someone else?

No. Mycobacterium chimaera infections cannot be spread from person to person.

Meet the expertMike Knapton

Dr Mike Knapton is Associate Medical Director (Prevention and Care) at the BHF, overseeing the strategic role in helping patients and the public reduce their risk of heart disease. He remains a GP and works one day a week at a practice in Cambridge.

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