Over half a million heart surgery patients at risk of deadly infection

Over half a million patients who had open-heart surgery in the US in the past several years could be at risk of a deadly bacterial infection linked to a device used during their operations, according to US federal health officials.

Such infections are rare, but nevertheless could cause serious illness or death. The infection was especially insidious because it was difficult to detect, with symptoms or signs taking  months to appear following initial exposure.

The past year alone had seen 28 cases, with hospitals in Iowa, Michigan and Pennsylvania reporting infections. Numerous infections had also have been reported in patients in Europe; with diagnosis in some cases almost four years after surgery.

The device, which is a piece medical equipment is known as a heater-cooler unit, and is an essential part of life-saving surgeries as it helps keep a patient's organs and circulating blood at a specific temperature during the operation.

It is used in an estimated 250,000 heart-bypass procedures in the US every year, with around 60 per cent of these procedures using the German-made model that had been linked to the infections.

The bacteria, known as non-tuberculous mycobacterium, or NTM, are commonly found in nature but are not typically harmful. However, NTM could cause infections in patients who had had invasive procedures, especially when they had weakened immune systems.

According to a news release by the US Centers for Disease Control and Prevention, people who had had open heart surgery should seek medical care if they had infection-related symptoms, such as night sweats, muscle aches, weight loss, fatigue or unexplained fever.

The agency added that hospitals and doctors should identify and inform patients who might be at risk.

"It's important for clinicians and their patients to be aware of this risk so that patients can be evaluated and treated quickly," said Dr Michael Bell, deputy director of the CDC's Division of Healthcare Quality Promotion, webmd.com reported.