Update - 11 August 2017
A fourth NSW case of Mycobacterium chimaera infection has now been confirmed. The case is in a man in his 60s who underwent open-heart cardiac valve surgery at Prince of Wales Hospital in 2015.
In December 2016 NSW Health contacted patients who may have been exposed to the M. chimaera infection from contaminated open-heart surgery equipment used in four affected NSW public hospitals.
In January 2017 two NSW patients, one a woman in her 80s and one a man in his 40s, both of whom had also undergone open-heart cardiac surgery at Prince of Wales Hospital in 2015, were confirmed to have developed the infection. A third NSW patient with M. chimaera was confirmed in March 2017, a man in his 80s who had undergone cardiac valve surgery at Prince of Wales Hospital in 2015.
Which open-heart surgery patients need to be aware of this risk?
- NSW Public Hospitals: Children’s Hospital Westmead, Prince of Wales, St George, Sydney Children’s (all Jan 2012 – Aug 2016)
- NSW Private Hospitals: Newcastle Private (July 2014 – Sept 2016), Norwest Private (Jan 2012 – August 2016), Prince of Wales Private (Jan 2012 – August 2016), St George Private (Jan 2012 – Jan 2017), The Sydney Adventist Hospital, Wahroonga (between 22 January and 18 June 2015), Westmead Private (June 2014 – Dec 2016)
- ACT: National Capital Private (Nov 2011-Aug 2016) and Canberra Hospital (Jul 2014 – Nov 2016)
As this is an international problem, patients who had cardiac surgery in other states or territories, or overseas could also have been exposed.
There is a risk that certain heater-cooler devices used in open-heart cardiac surgery may have been contaminated with a rare bacterium called Mycobacterium chimaera (or M. chimaera), and that exposure of patients to these units in the operating theatre may lead to infections that can appear months after the surgery.
Infection of cardiac surgery patients with M. chimaera associated with a particular heater-cooler device - the Stockert 3T made by Sorin (now known as LivaNova) - was first recognised in 2012 in Switzerland. These devices, which have been widely used around the world including Australia, are thought to have been contaminated during manufacture up until September 2014.
Cases of infection with M. chimaera infections after cardiac surgery have been reported from Switzerland, Germany, the Netherlands, England and the United States. The infection in these NSW residents brings the total reported in Australia to date to four, following an earlier case in Queensland - Queensland Health .
M. chimaera are slow-growing bacteria - infections have been diagnosed from months to up to several years after an open-heart surgery involving the implicated heater-cooler devices.
The Therapeutic Goods Administration (TGA) has provided alertson this issue and the Australian Commission on Safety and Quality in Health Care (ACSQHC) also issued new National Infection Control Guidance relating to heater-cooler devices in February 2017.
The overall risk to individual patients is thought to be very low. Initial information suggests that patients who had prosthetic implants (such as heart valve replacements) during their cardiac surgery are at a higher risk than those who did not receive implants.
In August 2016, NSW Health responded to international reports of infection in patients due to M. chimaera bacteria associated with open heart surgery machines by:
- Replacing or removing from service the small number of these machines used in the only four affected public hospitals – Prince of Wales Hospital, St George Hospital, Children’s Hospital Westmead and Sydney Children’s Hospital Randwick
- Issuing alerts to the community and doctors
- Circulating new national control guidelines for the devices.
In December 2016, the South-Eastern Sydney Local Health District and Sydney Children’s Hospital Network (SCHN) wrote to people who had open heart surgery at the four affected public hospitals from January 2012 to August 2016. The letters are informing patients of the measures taken by NSW Health and reassuring them that proactive monitoring is in place and that the risk of clinical infection remains extremely low.
Unfortunately, there is no test to tell if a patient has been exposed to the bacteria before symptoms of the infection develop.
Further information for patients
Patients seeking further details can contact the following information lines:
- Sydney Children’s Hospital Network – 02 9845 3442 (8.00am – 5.00pm)
- South Eastern Sydney Local Health District –1800 875 526 (8.00am – 5.00pm).
Further information for health care professionals
Further information for health facilities
Further information for laboratories
Sterile site samples from patients with prosthetic valve endocarditis, mediastinitis, infective endocarditis, graft infection, sternal wound infection or other cardiac or other transplanted organ infection three or more months post-cardiothoracic surgery (highest risk is valve surgery) should be cultured for Mycobacteria in addition to standard bacterial culture.
Alternatively, infected tissue samples, after the assessment of M. chimaera infection risk, can be subjected to panbacterial 16S rDNA PCR which is available at the ICPMR-Pathology West.
- US Food and Drug Administration. Food and Drug Administration. FDA Executive Summary. Nontuberculous Mycobacterium (NTM) Infections Associated with Heater-Cooler Devices (HCD) during Cardiothoracic Surgery. June 2016.
- Sax H, Bloemberg G, Hasse B, et al. Prolonged Outbreak of Mycobacterium chimaera Infection After Open-Chest Heart Surgery. Clinical Infectious Diseases. 2015; 61 (1): 67-75.
- Haller S, Höller C, Jacobshagen A, et al. Contamination during production of heater-cooler units by Mycobacterium chimaera potential cause for invasive cardiovascular infections: results of an outbreak investigation in Germany, April 2015 to February 2016. Euro Surveillance. 2016;21(17) .
- Kohler et al. Healthcare-associated prosthetic heart valve, aortic vascular graft, and disseminated Mycobacterium chimaera infections subsequent to open heart surgery. European Heart Journal 2015; 36(40).
- Chand et al. Insidious risk of severe Mycobacterium chimaera infection in cardiac surgery patients. Clinical Infectious Diseases (2016). Published online 7 Dec 2016. doi:10.1093/cid/ciw754.