Source: http://www.seattletimes.com, September 19, 2016
By: JoNel Aleccia
Bacteria that cause Legionnaires’ disease have been detected in University of Washington Medical Center devices used to heat and cool patients during heart surgery, the same type of machines linked to different types of deadly outbreaks in other hospitals.
Three so-called heater-cooler units, devices used during surgery to maintain a patient’s temperature, tested positive, UW Medicine officials said Monday. The discovery came during an investigation of at least four recent cases of Legionnaires’ disease, a serious type of pneumonia, including two patients who died.
Similar heater-cooler units recently were tied to deadly infections at a central Pennsylvania hospital in 2015 and in other sites. The bacteria found in some cases were identified as nontuberculosis mycobacterium, or NTM, slow-growing bugs found in water and soil. Other bacteria called mycobacterium chimaera were also linked to infections not normally found in people.
But the UW Medicine outbreak appears to be the first public report of Legionella bacteria tied to the machines.
“Legionnaires’ disease has not been previously proven to be transmitted in this fashion,” Tina Mankowski, a UW Medicine spokeswoman, said in a statement Monday. No direct link with patient infections has been confirmed.
Hospital officials said the water in the machines doesn’t come into contact with the patient’s blood at any time during the process. But the federal Food and Drug Administration (FDA) reported 32 patient infections associated with heater-cooler units between January 2010 and August 2015 and indicated that transmission of bacteria was possible.
“Although the water in the circuits does not come into direct contact with the patient, there is the potential for contaminated water to enter other parts of the device or transmit bacteria through the air,” FDA officials wrote.
UW Medicine officials previously said Legionella bacteria had been found in an ice machine and sinks in the hospital’s Cascade Tower. On Monday, they reported that tests of three of the hospital’s 12 heater-cooler units tested positive for the germs.
“We thoroughly cleaned and sanitized them and took them out of service as an additional precautionary measure,” Mankowski’s statement said.
The manufacturer of the devices, CardioQuip of Bryan, Texas, will be on site this week to disassemble and clean the machines, she added.
Hospital officials said the CardioQuip heater-cooler units have not been implicated in previous outbreaks. Surgeries that require use of the devices will continue using the units that tested negative for Legionella bacteria, they added. Of the four patients who were infected, two had surgeries that involved the heater-cooler units.
“Exposure to water in the Cascade Tower inpatient units is highly likely to be the source of the Legionella infections (not exposure to the heater/cooler units),” Mankowski said in an email.
The Cascade tower water system will be flushed with chlorine Monday night. Bottled water was being provided for drinking and hand washing, officials said.
UM Medicine performs about 50 surgeries a month that use the heater-cooler units. The hospital is calling all high-risk patients who were hospitalized between Aug. 24 and Sept. 13 in the Cascade Tower. That includes patients who used heart-lung machines that temporarily take over functions of the heart and lungs during surgery.
The implications of detecting Legionella bacteria in heater-cooler units, which have been widely used in U.S. hospitals for years, are sobering, said Lawrence Muscarella, a patient-safety advocate and infection-control consultant.
“These heater-coolers are being used all over the country,” he said. “There are literally tens of thousands of people at risk now of having been exposed to NTM and Legionella.”
Like medical scopes that can’t be properly cleaned, the heater-cooler devices may be designed in a way that prevents them from being thoroughly disinfected, Muscarella said.
Two men in Pennsylvania filed a $5 million federal class-action lawsuit against LivaNova PLC, a London-based maker of heater-cooler units, claiming they had been exposed to dangerous NTM bacteria during surgery.
UW Medicine officials said they’ve notified officials with the Centers for Disease Control and Prevention (CDC), which also issued a warning about the devices in 2015. Officials with the FDA and the CDC said they were looking into the UW Medicine report.
The Seattle investigation follows reports of four cases of Legionella infection in patients treated at UW Medicine, including those treated in the cardiac units. They included a 30-year-old woman reported on Aug. 26 and a 50-year-old man reported Sept. 6. The man died on Sept. 8.
A woman in her 50s who died on Aug. 27 had a Legionella infection detected during autopsy. And a fourth patient, a man in his 40s, was diagnosed last week.
Legionnaires’ disease typically occurs when people breathe in mist or vapor contaminated with the bacteria. Healthy people who are exposed don’t usually get sick, but those who are older than 50, current or former smokers or who have weakened immune systems are more vulnerable.