Mycobacterium chimaera is one of a group of bacteria called Non-Tuberculous Mycobacterium (NTM) which are commonly found in the environment, including water. NTM typically are not harmful; however, in very rare cases, they can cause infections in post-operative surgical patients, especially in people with weakened immune systems. The LivaNova (Sorin) heater-cooler medical device used in open-heart surgery in Australia and around the world can cause M. chimaera infection.
Mycobacterium chimaera (M. chimaera) is a type of bacteria that can be found in water and soil.
M. chimaera only rarely causes infections in people. People with weakened immune systems, who have lung disease or diabetes, or who are undergoing chemotherapy are more likely to get M. chimaera.
People having serious surgeries such as open-heart surgery are also at risk. This is because a particular heater-cooler medical device used in open-heart surgery around the world and in Australia can cause M. chimaera infection. The device type is LivaNova (Sorin).
It can take months to years for symptoms of M. chimaera infection to appear. To date, the longest time after surgery for an infection to be identified is 12 years.
The most common symptoms are persistent fevers, increasing or unusual shortness of breath, and unexplained weight loss. Other symptoms of M. chimaera:
M. chimaera does not spread from person-to-person, but the bacteria can be found in the environment.
The bacteria can grow in the water tank of heater-cooler machines used during open heart surgery. These machines keep the patient's blood at the correct temperature during the heart surgery. Contaminated water droplets from the tank may spread bacteria through the air to the patient during the surgery. The water does not come into contact with blood or body fluids.
Over 120 patients worldwide have had M. chimaera infection after open heart surgery, including eight patients who had surgery in NSW.
People who have had open heart surgery are at risk of M. chimaera infection.
Anyone who had open heart surgery at the following NSW hospitals at a particular time period may have been exposed. Known risk periods in NSW hospitals are shown below.
Some people may have been contacted by their hospital directly. Talk to your specialist or general practitioner if you have symptoms or any other concerns.
In NSW, hospitals have reviewed their processes to reduce the risk of infection. All heater-cooler devices in NSW public hospitals are tested for Mycobacteria every 3 months.
All current LivaNova (Sorin) heater-cooler devices in public hospitals have been retro-fitted with an aerosol collection device. This device removes exhaust from the machine when it is in use, further reducing the risk to patients.
Blood or other samples can be taken to test for M. chimaera in people who have symptoms. There is no test to show if people who are well are at risk of developing symptoms of the infection in the future.
M. chimaera infections can be treated with antibiotics. Some patients who become infected may need longer treatment. Some patients may need further surgery. If untreated, M. chimaera infection can lead to death.
If M. chimaera is detected in a heater-cooler device used in open-heart surgery, the hospital will contact patients who may have been exposed to provide advice.
For further information, call your local Public Health Unit on 1300 066 055 or visit the NSW Health website.