The CDC has posted new guidelines to help infection preventionists and epidemiologists identify cases of non-tuberculosis mycobacterium (NTM) in cardiac surgical patients exposed to heather-cooler units during their procedure.1
“Given the increasing number of reports we are receiving across the U.S. of facilities that are dealing with this issue, these guidelines can assist healthcare facilities in trying to identify patients with NTM infections that might be associated with exposure to these heater-cooler units,” says Kiran Perkins, MD, MPH, a medical officer in the CDC Division of Healthcare Quality Promotion. “We are emphasizing a high index of suspicion for NTM infection in patients who had exposure to cardiopulmonary bypass.”
Hospitals performing surgeries requiring cardiopulmonary bypass should consider taking the following steps to identify patients at risk, the CDC recommends. Patients meeting the following criteria may represent heater-cooler unit-associated infection and may warrant additional investigation.
Laboratory assessment: Identify NTM-positive cultures obtained from an invasive sample (blood, pus, tissue biopsy, or implanted prosthetic material) using facility’s microbiologic database or other appropriate sources. The time period for review is institution-dependent. Some institutions have used a four-year time period to conduct laboratory review, whereas other facilities have opted for a longer time frame.
Clinical assessment: Cross reference NTM-positive cultures with medical and surgical records to identify patients who meet the following clinical criteria (any one of the following):
- prosthetic valve endocarditis;
- prosthetic vascular graft infection;
- sternotomy wound infection;
- bloodstream infection;
- disseminated infection, including embolic and immunologic manifestations (e.g. splenomegaly, arthritis, osteomyelitis, bone marrow involvement with cytopenia, chorioretinitis, lung involvement, hepatitis, nephritis, myocarditis).
Exposure assessment: For patients identified using the criteria above, assess for a history of surgery requiring cardiopulmonary bypass prior to diagnosis of NTM infection.
- Consider institution-specific strategies for alerting patients and providers of the risk of infection given exposure to potentially contaminated heater-cooler units.
- Order acid-fast bacilli (AFB) culture in any patient with exposure history and meeting the clinical criteria, or presenting with signs or symptoms of NTM infection such as recurrent or persistent fever of unknown etiology, night sweats, joint or muscle pains, weight loss, or fatigue. If AFB culture is positive for Mycobacterium avium complex, consider sending a sample for further speciation to an NTM reference laboratory.
- Submit FDA MedWatch Report for positive cases.
- Alert the appropriate local or state health department.
- CDC. Interim Guide for the Identification of Possible Cases of Nontuberculous Mycobacterium Infections Associated with Exposure to Heater-Cooler Units: www.cdc.gov/hai/pdfs/outbreaks/Guide-for-Case-Finding.pdf.