New DNA evidence strengthens the link between worldwide outbreaks of nontuberculous mycobacterium and heater-cooler devices manufactured in Germany by the London-based devicemaker LivaNova, according to research published Wednesday in The Lancet Infectious Disease.
Here are seven things to know.
1. In 2015, news broke of open-heart surgery patients in the U.S. and Switzerland contracting NTM infections. Investigators eventually linked the infections to heater-cooler devices, which run on water and are used to heat and cool patients during heart surgery.
2. In October 2016, the CDC said the infections were specifically linked to Stöckert 3T heater-cooler devices made by LivaNova, formerly known as Sorin Group Deutschland. CDC investigators believed the devices were contaminated during manufacturing with Mycobacterium chimaera, a species of NTM bacteria found in soil and water. While the bacteria rarely make people ill, open-heart surgery patients can contract difficult to diagnose, slow-growing infections from the bacteria during surgery. The infections can be life-threatening.
3. While Mycobacterium chimaera was previously identified at the LivaNova manufacturing site in Munich, Germany, the new study strengthens the link with DNA evidence.
4. Researchers examined 24 isolates extracted from 21 infected patients in Switzerland, Germany, the Netherlands and the United Kingdom. The team compared the isolates with samples from the LivaNova devices, heater-coolers manufactured by another German company and samples from hospital water sources and other environmental sources.
5. Researchers identified a high degree of similarity between the LivaNova samples and samples taken from infected patients.
6. "Our study closes the missing [evidence] gap," said Dr. Stefan Niemann, a professor with the German Center for Infection Research, in a release cited by Kaiser Health News.
7. LivaNova said the study was too limited to determine an accurate conclusion.
"LivaNova is concerned that the article expresses a level of certainty about a point source tie to the manufacturing process that is not warranted by the data," company spokeswoman Deanna Wilke wrote in an email to Kaiser Health News.
To read KHN's full report, click here.
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