Collection

Mycobacterium chimaera: infections linked to heater cooler units

Guidance for healthcare professionals on infection control and clinical aspects of M. chimaera infection associated with cardiopulmonary bypass.

• From: UK Health Security Agency
• Published: 9 June 2015
• Last updated: 23 September 2024 — See all updates

Mycobacterium chimaera (M. chimaera) is an environmental non-tuberculous mycobacteria belonging to the Mycobacterium avium complex. It has been recognised as a cause of endocarditis, severe disseminated infection and chronic sternal wound infection in patients who have undergone cardiothoracic surgery.

M. chimaera may manifest many years after surgery undertaken on bypass. Investigations in multiple countries shows this is likely to be transmitted from heater cooler units, which are part of the cardiopulmonary bypass equipment.

The risk of infection is low (see updated risk assessment) and control measures are already in place. However, M. chimaera infection can have an insidious and non-specific presentation, is not always identified through conventional microbiology, and requires specific treatment.

As of 25 April 2024, there were 58 cases of M. chimaera infection following surgery on cardiopulmonary bypass, of which 44 were known to have died. The median interval between surgery and diagnosis is 26 months but ranges from less than 1 to 154 months.

Guidance for healthcare providers and health professionals

• Infections associated with heater cooler units used in cardiopulmonary bypass and ECMO
  • 20 February 2017
  • Guidance
• Mycobacterium chimaera infections: information for GPs
  • 20 March 2017
  • Guidance
• Mycobacterium chimaera infections: guidance for secondary care
  • 20 February 2017
  • Guidance
• Slow growing mycobacteria: procedure for testing heater cooler units
  • 1 February 2018
  • Guidance
• Atypical mycobacterial infection diagnosed following cardiopulmonary bypass: surveillance form
  • 25 April 2024
  • Form

Epidemiology

• HPR volume 18 issue 4: news (25 April 2024)
  • 31 October 2024
• HPR volume 15 issue 16: news (30 September)
  • 19 January 2022

Published 9 June 2015
Last updated 23 September 2024 + show all updates

1. 23 September 2024

   Added latest HPR.

2. 25 April 2024

   Updated number of cases and deaths and added Epidemiology section.

3. 16 February 2024

   Updated number of deaths.

4. 10 October 2023

   Updated number of cases and deaths.

5. 8 June 2023

   Updated number of deaths.

6. 20 October 2022

   Updated number of deaths.

7. 30 September 2021

   Updated number of cases.

8. 7 December 2020

   Updated number of cases.

9. 15 July 2020

   Updated number of cases.

10. 18 September 2019

    Updated number of cases.

11. 14 January 2019

    Updated number of cases.

12. 18 September 2018

    Updated number of cases.

13. 1 March 2018

    Updated number of cases and deaths.

14. 30 November 2017

    Updated number of cases.

15. 8 September 2017

    Updated number of cases.

16. 31 July 2017

    Confirmed current UK case numbers.

17. 30 June 2017

    Updated number of cases.

18. 31 May 2017

    Updated number of cases.

19. 28 April 2017

    Updated number of cases.

20. 20 March 2017

    Added guidance for GPs.

21. 17 March 2017

    Updated number of cases.

22. 9 March 2017

    Investigation reports section updated

23. 22 February 2017

    Added a link to the finding of a UK investigation.

24. 20 February 2017

    Updated with latest version of guidance for healthcare providers and added guidance for healthcare professionals in secondary care.

25. 20 January 2017

    Added update on outcomes.

26. 5 November 2015

    Updated guidance and reporting form.

27. 9 June 2015

    First published.