Three Melbourne hospitals have replaced heart surgery equipment after it was found to be contaminated with a harmful bacterium that has caused infections for dozens of patients across the world.
Victoria’s health department said an unusual bacterium, Mycobacterium chimaera (M. chimaera), had been detected in heater-cooler units used for heart surgery at The Alfred, Austin and Cabrini hospitals in Melbourne.
“All the units were decommissioned and replaced once the test results were known,” a department spokesman said.
Doctors are now checking patient records at the hospitals to assess whether any may have been harmed by the bacterium, which can cause serious illness.
The move comes after the Therapeutics Goods Administration revealed an Australian patient had potentially contracted an infection from a piece of contaminated surgical equipment during open heart surgery. The contaminated equipment has been linked to dozens of infections globally in recent years.
It is unclear in which state the Australian patient had surgery, but both New South Wales and Victorian health authorities said no cases had been detected in their states yet.
On Tuesday, the NSW health department said it had removed equipment from Prince of Wales and St George hospitals, as well as the Sydney Children’s Hospital at Randwick and the Children’s Hospital at Westmead.
NSW Health also advised patients to see their doctors if they had undergone open heart surgery at the hospitals in the past five years.
A Victorian health department spokesman said they felt no need to contact Victorian patients potentially exposed to the bacterium, because the risk was so low. However, he said doctors were examining patient records at the three hospitals to ensure there were no signs of a missed case.
In a statement issued on Tuesday night, Victoria’s chief medical officer Dr Andrew Wilson said: “International and Australian expert assessment has found that there is a very low risk of infection, and this risk appears to be limited to patients who have had cardiac valve replacements where affected units were used, although cardiac transplants and those who had coronary artery bypass surgery may also be very rarely affected.”
Professor Lindsay Grayson, director of infectious diseases and microbiology at the Austin Hospital, confirmed two Sorin machines had been used in heart surgery since mid-2013, and one was found to have been contaminated on Thursday. Both machines have since been replaced.
He said patients that were exposed were those who had an artificial heart valve or other prosthetic material inserted. He said there was a one in 10 000 chance that the bacterium would cause an infection, and warned that avoiding heart surgery was more dangerous.
“If you think about this, the chances of having a car accident are one in 4000, so it is very rare.”
Professor Grayson said while the infection could be fatal if it was not treated properly, it could be cured with surgery and a prolonged use of specific antibiotics.
“We have nothing to hide at the Austin, we are absolutely concerned about what has gone on, but according to our investigation until now we don’t have a case.”
M. chimaera infections in cardiac surgery patients overseas have been linked to the heater-cooler units made by medical equipment manufacturer Sorin. It is thought that the units were contaminated during their manufacture.
The contaminated units, which control the temperature of the blood during the procedure, transmit the infection to the formerly sterile surgical area and the heart’s new implanted valve and graft.
The first identified case of the infection linked to the units was in Switzerland in 2012.
Internationally, 56 patients have been identified as having the infection after undergoing the procedure where the contaminated equipment was used, the US Food and Drug Administration reported in 2015.
The infections were identified between three months and five years after surgery.
Several independent studies reported open heart surgery patients had developed postoperative prosthetic-valve endocarditis caused by the mycobacteria.
Symptoms of the infection could include fever lasting more than a week, pain, redness, heat, pus around a surgical incision, night sweats, joint and muscle pain loss of energy and failure to gain weight, or failure to grow in children.
A safety notice was issued to public and private health facilities on July 8, and updated on August 4, to notify clinicians of the very low risk of infection, the department said.
More detailed information was provided to cardiologists, cardio-thoracic surgeons, clinical microbiologists and laboratories, and a fact sheet for open-heart surgery patients was prepared.
The TGA said people concerned about the problem in Australia should contact their doctors.