Health conditions

Mycobacterium chimaera in heater-cooler devices

  • Some heater-cooler devices (HCDs) used in open-heart surgery may have been contaminated with a rare environmental bacterium called Mycobacterium chimaera.
  • Exposure to aerosols from HCDs may lead to infections in patients that can appear months to years after surgery.
  • No patients in Western Australia have developed this infection.

There is a risk that some heater-cooler devices (HCDs) used in open-heart surgery may have been contaminated with a rare environmental bacterium called Mycobacterium chimaera. M. chimaera is one of a group of bacteria known as non-tuberculous mycobacteria (NTM) which are not usually harmful. However, in very rare cases, they can cause infections in surgical patients.

Exposure to aerosols from HCD these devices may lead to infections in patients that can appear months to years after surgery. These devices are widely used around the world, including in Australia.

As at 10 February 2017, there have been 3 patients in Australia who have been identified with M. chimaera infection associated with HCDs. No patients in Western Australia have developed this infection and, as a precautionary measure, those patients at risk of this infection will be provided with information about the risk.

Am I at risk?

It appears that the risk may be higher in certain surgeries that involve the insertion of artificial heart valves or grafts.

A person may be at risk if they had such an operation in the last 5 years at:

  • Fiona Stanley Hospital
  • Fremantle Hospital
  • Mount Hospital
  • Princess Margaret Hospital
  • Royal Perth Hospital
  • St John of God Subiaco Hospital.

Patients who had surgery performed at Sir Charles Gairdner Hospital (SCGH) are not believed to be at any risk of M.chimaera infection as the HCDs at SCGH have repeatedly tested negative for M.chimaera.

Is there a risk to my family and friends?

No. M. chimaera is not contagious. This means that, even if you had the infection, it cannot be spread from person to person through contact.

What are heater-cooler devices?

Heater-cooler devices are used during open-heart surgery to warm or cool a patient’s blood during the procedure. It has been recognised that there is the potential for M. chimaera to grow in a water tank in the device. Although the water in the HCDs does not come into contact with the patient’s blood, it is possible for the bacteria in contaminated water drops to become airborne and then settle on a patient during open-heart surgery.

What are the signs and symptoms?

Signs of a possible M.chimaera infection may include:

  • unexplained fevers
  • unexplained weight loss
  • increasing shortness of breath
  • night sweats
  • joint or muscle pains
  • nausea, vomiting or abdominal pain
  • pain, redness, heat or pus around the surgical site.

As signs and symptoms are not limited to those listed above, it is important for you to speak to your family GP if you are concerned about any unexplained illness.

How is it diagnosed and treated?

Your doctor will conduct initial examinations and you may be referred to an Infectious Disease Physician for further assessment. M. chimaera infections can be treated with antibiotics. There is no role for antibiotics if you are well and there is no vaccine available.

How can it be prevented?

All WA public and private hospitals that perform open-heart surgery have tested their HCDs to determine if the bacterium is present. Hospitals with contaminated devices have implemented processes to reduce the risk of patients acquiring an infection.

In addition, the contaminated HCDs have either been disinfected to remove the bacterium or have been replaced with new HCDs.

Regular testing of the HCDs is ongoing at all hospitals and no further positive results have been identified.

Where to get help

  • See your doctor
  • Visit a GP after hours
  • Ring healthdirect on 1800 022 222

Last reviewed: 28-02-2017

Last updated: 29-03-2017
Acknowledgements

Public Health


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