Risk for heart patients

Thousands of Kiwis who had open-heart surgery face a small, but serious risk of infection, due to a potentially contaminated device used in their procedure.

About 5900 patients who received artificial valves since 2013 at five major public hospitals have been sent letters from the Ministry of Health, via district health boards, telling them a device used in their surgery may have been contaminated with a germ.

A Waikato DHB spokeswoman said no cases of infection had occurred in the Waikato region, although a total of 1193 letters were sent to patients on Friday as a precaution.

Auckland DHB sent letters to 2490 patients, including 950 children who had cardiac surgery at Starship Hospital.

One suspected case has already been identified and treated in New Zealand, the letter said, as officials confirm the machine is still in use.

The rate of infection is estimated to be one in 5000 procedures, but the bacteria can take years to take hold.

The device is a machine known as a heater-cooler, used in many open-heart surgeries to control blood temperature.

The units contained tanks of temperature-controlled water that was not intended to come in contact with the patient or their blood.

‘‘Water within some of the heater-cooler units had become contaminated with bacteria and patients were potentially exposed to the bacteria when the water in the heater-cooler units became aerosolised during use,’’ ministry chief medical officer Dr Andrew Simpson said.

A Waikato DHB spokeswoman said the hospital’s heater cooler devices had been checked and deep cleaned or were brand new.

‘‘We have a system in place to ensure future patients are not exposed to the bacteria.’’

Those who had surgery from January 1, 2013, at five public hospitals across the country – Auckland, Starship, Waikato, Christchurch and Wellington – should have been notified or have letters enroute.

Those are the only public hospitals which perform this type of surgery, so patients could have come from anywhere in the country.

Some private hospitals, including Mercy Ascot in Auckland and St George’s in Christchurch also perform open-heart surgery and should be notifying patients of the risk.

Symptoms can take between three months and five years to be diagnosed and include fevers or night sweats, unexplained weight loss, fatigue, chest pain, infection around the site of surgery, increased shortness of breath, joint or muscle pain and nausea, vomiting or abdominal pain.

Canterbury DHB clinical microbiologist Dr Josh Freeman said treatment requires a long course of antibiotics and often surgery on the affected heart valves.