The NHS is today (Tuesday 21st March) taking the precautionary step of writing to patients who have had certain types of open heart surgery to inform them that they may have a  low risk of having contracted an infection caused by Mycobacterium chimaera (M. chimaera).

Over the next two weeks, letters are being sent to patients in England, Scotland, Northern Ireland and Wales who have had heart valve replacement or valve repair surgery, including procedures undertaken as part of congenital heart disease surgery, since January 2013.

This is a world-wide issue and NHS England, Public Health England and the Medicine and Healthcare Products Regulatory Agency issued guidance to surgical centres in November 2015 after Mycobacterium chimaera infection risk was identified. No cases of the infection have been identified in patients who had surgery since this guidance was published, but the situation is being monitored closely.

The advice follows information indicating that some heater-cooler devices, which are used to help keep a patient’s blood and organs at a specific temperature during surgery, might be contaminated by M chimaera and could therefore put patients at risk of infection.

This is a precautionary exercise. The risk of contracting the infection is considered low, and it cannot be spread from person-to-person. There is no need for those who have already had valve replacement or repair surgery to be concerned unless they experience symptoms of infection, which include:

• Unexplained fevers or night sweats (waking up with bed sheets showing signs of sweating)
• Unexplained weight loss
• Increasing shortness of breath
• Joint or muscle pain
• Nausea, vomiting or abdominal pain
• Abnormal levels of tiredness/fatigue
• Pain, redness, heat or pus around the surgical site.

Patients with these symptoms – for which there are much more common causes – should not be alarmed or seek emergency treatment, but should contact their doctor, even if their surgery was many years ago.

Patients who have had other types of open heart surgery have a minimal risk of contracting this infection and are not being proactively contacted, but should contact their GP if they experience these symptoms.

The risk of contracting an infection is far lower than the risk of delaying life-saving cardiac surgery, but any patients with concerns are encouraged to discuss them with their surgeon or care team.