Non-tuberculous Mycobacterium (NTM) Infections and Heater-Cooler Devices

Nontuberculous mycobacteria (NTM)Mycobacterium spp. that do not cause TBM. avium complex (MAC) among most common NTMMAC: Slow-growing, ubiquitous in environmentSurface water, tap water, and soilVery low virulence, opportunistic pathogensDisseminated disease only with extreme immune compromise (e.g. AIDS with low CD4 count)Lung disease among those with airway abnormalitiesRarely considered a healthcare-associated threatSpecial methods needed for culture detectionNo person-to-person transmission

Invasive M. chimaera infection in 6 patientsM. chimaera is one species of MAC (ID by DNA sequencing)All six patients had cardiac implants (2008-2012)Time from surgery to diagnosis: 1.7-3.6 yearsEndocarditis, graft material, bloodstreamTwo of six patients diedInvestigation of water sources revealed:Water in heater-cooler units grew outbreak strainAir samples grew outbreak strain when units ran

Clin Infect Dis 2015 (July 1);61:67

Additional outbreaks and cases detected in multiple countriesNetherlands (1), England (7), Germany (1), Switzerland (6)US: First major recognized outbreak in PAWellSpan, York, PA: 8 probable cases, 4 deathsInvestigation confirmed heater-cooler unit sourceFDA alert and CDC guidance issued 10/2015More rigorous cleaning and disinfectionAssess for NTM infection in those with symptoms who had cardiac surgery in prior 4 yearsMycobacterial cultures from blood or affected sitehttp://www.cdc.gov/HAI/pdfs/outbreaks/CDC-Notice-Heater-Cooler-Units-final-clean.pdfClinical ManifestationsProsthetic valve endocarditisVascular graft infectionDisseminated infectionSplenomegalyArthritisOsteomyelitisCytopenias (bone marrow involvement)ChorioretinitisLung involvementHepatitisNephritisMyocarditis

Kohler et al. Eur Heart J 2015;36:2745

M. chimaera detected in heater-cooler unit water and in air samples, but only while the unit was runningClin Infect Dis 2015 (July 1);61:67

15: Fan16: VentilationAlthough water from heater-cooler unit never contacts patients directly, the ventilation fan can aerosolize contaminated water from the circuitFDA safety communicationFor all heater-cooler devices:Adhere to manufacturer instructionsUse only sterile or filtered water (0.2 micron)Direct unit exhaust away from operative fieldRemove units with signs of contaminationReport any case of NTM infection after device usehttp://www.fda.gov/MedicalDevices/Safety/AlertsandNotices/ucm466963.htm10/15/15.

CDC GuidanceThe most important action to protect patients will be to remove contaminated heater-coolers from operating rooms, and ensure that those in service are correctly maintained.

http://www.cdc.gov/HAI/pdfs/outbreaks/CDC-Notice-Heater-Cooler-Units-final-clean.pdf. 10/27/15.PA DOH AdvisoryRisk: approximately 1:10,000 to possibly 1:100 among patients undergoing open heart surgery on CPB. Patients and providers should not delay cardiac surgeries after appropriate informed consent.Several important unknowns:Whether the risk of NTM infection can be completely eliminated The degree to which only certain models of HCUs will aerosolize bacteria or whether all HCUs have the potential to aerosolize bacteria The ability of stated disinfection procedures to adequately decontaminate a colonized machine

Pennsylvania Department of Health, Advisory #322, 12/11/15.ChallengesCase finding: Many patients receive follow-up care locally, not at UIHCSymptoms can be very nonspecific (fever, fatigue, arthralgias, myalgias)Symptoms can present up to 4 years after the exposure (long incubation period)Mycobacterial cultures are not routinely performed, but are required for diagnosisFor above reasons, the true extent of this problem is not currently knownVery difficult to treat (multiple drug therapy, surgical removal of involved devices)