M. chimaera infections associated with cardiopulmonary bypass
A paper in Clinical Infectious Diseases last year described an outbreak of these infections in Switzerland. The outbreak investigators determined that the water used in the heater-coolers became contaminated by M. chimaera. This water never comes into physical contact with the patient, but the investigators found that a fan on the heater-cooler unit aerosolized the organism into the air leading to direct contamination of the surgical wound. When the heater-cooler devices were present in the operating room but not turned on, the organism was not aerosolized.
Most of the reported cases have manifested as prosthetic valve endocarditis or vascular graft infections, and there may be involvement of the bone marrow causing cytopenias, as well as splenomegaly. The patients were not immunosuppressed. Often these patients presented with nonlocalizing symptoms, such as fever, mylagias, arthralgias, fatigue and weight loss. The mortality rate is approximately 50%.
Several issues make case finding problematic:
If your hospital performs procedures requiring cardiopulmonary bypass, the most important control measure to prevent infection is to move the heater-cooler devices out of the operating room. Our engineers were able to develop a solution and accomplish this within 24 hours. In addition, ensure that the devices are being disinfected according to manufacturers’ guidelines.
M. chimaera is one of 8 species in the M. avium complex, and was recognized as a a distinct species in 2004. Given the ubiquitous nature of nontuberculous mycobacteria, we suspect that the cases linked to heater-cooler devices reported to date represent only the tip of the iceberg, and it is likely that more hospitals will be facing extensive look-back investigations.
Links to key references are below:
Several issues make case finding problematic:
- The time to diagnosis can be up to four years, as the incubation period for the infection due to this slow-growing mycobacterium is long, and diagnosis is often delayed since the organism isn’t detected in routine cultures.
- Symptoms of the infection are often nonlocalizing.
- We rarely order mycobacterial blood cultures in nonimmunosuppressed patients, and these cultures are key to making the diagnosis since most of the patients have infections of endovascular grafts or prosthetic cardiac valves.
- Given that Iowa is primarily rural, many patients receive their post-operative care by local providers, making it more difficult to identify cases.
If your hospital performs procedures requiring cardiopulmonary bypass, the most important control measure to prevent infection is to move the heater-cooler devices out of the operating room. Our engineers were able to develop a solution and accomplish this within 24 hours. In addition, ensure that the devices are being disinfected according to manufacturers’ guidelines.
M. chimaera is one of 8 species in the M. avium complex, and was recognized as a a distinct species in 2004. Given the ubiquitous nature of nontuberculous mycobacteria, we suspect that the cases linked to heater-cooler devices reported to date represent only the tip of the iceberg, and it is likely that more hospitals will be facing extensive look-back investigations.
Links to key references are below:
- Swiss outbreak investigation (Clinical Infectious Diseases)
- Review article on M. chimaera infections following cardiac surgery (European Heart Journal)
- CDC Guidance
- FDA Alert
- Pennsylvania Department of Health Advisory
- Pennsylvania Outbreak (New York Times)
Hi Mike. Are you able to provide more details (and perhaps some images) about how your hospital engineers were able to move the heater-cooler devices out of the operating room? regards
ReplyDeleteGlenys Harrington
Infection Control Consultancy(ICC)
Melbourne, Australia
Middle Park
Victoria, 3206
Australia
M: +61 404 816 434
infexion@ozemail.com.au
ABN 47533508426
Fascinating... look forward to updates... Philip Lederer
ReplyDeletei first suspected and published this risk in the U.S. in 2014, adding that a deadly mycobacterial outbreak in SC was likely due to a contaminated heater-cooler. FDA documents support my conclusion. Some of my comments appear in the SC and PA press. Arguably, a more prompt response on a federal level was necessary to prevent subsequent outbreaks, deaths at U.S. hospitals including University of Iowa's. LF Muscarella PhD
ReplyDeleteThanks, Dr. Muscarella. I agree with you, and with your comments in an article from the York newspaper over the weekend. A couple minor points--the SC outbreak that you refer to was due to a very different species of mycobacteria--M. abscessus, one of the "rapidly growing mycobacteria". While equally serious and often linked to hospital water systems, these infections are more likely to be identified due to the fact that the organisms grow much more quickly in the laboratory. The M. chimaera cases are much more difficult to diagnose, and thus more likely to "fly under the radar". I'll be posting more on this shortly. The other point that isn't as minor--your post implies deaths have been identified at University of Iowa related to this problem. That isn't the case--so far we have identified a single case, no deaths, but as Mike points out above we are currently in the midst of a patient notification and look-back investigation. Thanks for your comments, I know you've been on this issue for some time now. Dan
ReplyDeleteSirs, the research I just completed suggests Iowa City's NTM infection might have been avoided if there was more transparency in health care and shared information among hospitals. See: http://endoscopereprocessing.com/2016/02/a-deadly-bacterial-outbreak-at-greenville-memorial-hospital-in-2014-was-a-heater-cooler-device-the-cause/
ReplyDeleteBoth my son's equipment just tested positive in Brisbane Australia.
ReplyDeleteI just got a letter from the hospital that did my mothers heart surgery and they are giving me the run around how can I get in touch with you to study my mom's case to see if this is what caused her death. Please help!!!
ReplyDeleteThanks
Jill - Tulsa, OK
Hi Jill,
Deletemy mobile contact number is M: +61 404 816 434
Hi, Jill and Glenys, My father passed away in March after a 2 month stay in the hospital and we did not really get any answers that satisfied us from the hospital, the whole thing was unclear. My father had a heart valve replacement in December of 2011 and the hospital that performed the surgery sent us a letter advising us of the possible infection. It is quite a long story but after reading your article and doing some research for ourselves........ I believe we have the closest thing to an answer possible. My father had nearly all the symptoms listed , plus some. I am curious if there is anymore info available, or if there is someplace that you know of that we could consult. Thank you for your time, Joe
DeleteI am sorry for your loss, my story is pretty much what happened to my partner, but we did get a diagnosis, but much to late. The frustrating thing is we asked numerous times if this could be from his open heart surgery, they dismissed it.
DeleteGreetings, I received a letter from the hospital where I underwent bypass surgery on Oct 18, 2016 alerting me of a potential risk of a rare infection related to my surgery. Although I better understand the source of the concern I still don't know what I or my primary care physician can do to get ahead of the problem. If it requires waiting till symptoms appear, well many of the symptoms are also potential side effects of the medications prescibed after this kind of surgery. I guess what I'm asking is, is there a specific test I should request during my next check-up this month with my primary care physician to detect the infection or rule it out? Also, as an artificial hip recipient in 2014 I'm always wary of infections that might compromise the integrity of the hip. I know there is some disagreement whether that would be a concern this far out from that procedure but my orthopedist is very insistent I take precautions. Would this mycobacteria pose a potential risk to the hip? Obviously this news has my attention.
ReplyDeleteHello, Can you tell me the difference between Strep viridans endocarditis, and how the Prosthetic Valve Endocarditis and Bloodstream Infection Due to Mycobacterium chimaera are different?
ReplyDeleteI would like to say that my partner had surgery in November of 2015, and died March of this year. He was a healthy 57 year old that was misdiagnosed for month. This is so shameful and devastating.
ReplyDeleteMay I add, that his diagnosis was confirmed with an Rna test as M. Chimaera.
DeleteSo very sorry for those of you who have lost a loved one needlessly. My father had bypass in Oct 2013, started displaying symptoms mid 2014, has been misdiagnosed with Multiple Myoloma, Lymphoma, Breast Cancer and Sarcoidosis. Didn't get his letter until April 4, 2017, although other hospitals in Canada sent theirs out as early as October 2016. He had blood and bone marrow tested last week. I find it questionable that Canada has had no confirmed cases other than 2 in Quebec. I was told by Health Canada that the sequencing suggested by Dr Charles Daley is not mandatory here. I wish we could pay to have his blood tested properly. I fear a false negative will be the death of him.
ReplyDeleteI'm sorry Cari. If the hospitals at Health Canada would send us at National Jewish Health (Charles Daley is my colleague here where I do the genome analysis and surveillance of M. chimaera isolates that we receive) the M. chimaera isolates, we can confirm via Whole Genome Sequencing.
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