1388. Characteristics of Non-Tuberculous Mycobacterial Infections in Hematopoietic Stem-Cell Transplant Patients

BACKGROUND: Hematopoietic stem cell transplantation (HSCT) recipients are at increased risk for non-tuberculous mycobacterial infections (NTMI), but little data exists regarding NTMI in this population. This study aimed to better define the clinical and epidemiological characteristics of NTMI in HSCT patients. METHODS: We performed a retrospective review of patients age ≥ 18 who underwent HSCT between 2000 and 2017 at Yale-New Haven Hospital, and who subsequently had an NTMI based on ATS/IDSA criteria or a culture that grew NTM. We reported patient demographics, illness severity, treatment, and outcomes. RESULTS: Of 1371 HSCT recipients between 2000 and 2017, 17 (1.2%) had an NTMI or were culture positive. Most patients were male (76.5%), received allogeneic HSCT (70.6%), had graft vs. host disease (GVHD) (70.6%), and received immunosuppression (64.7%). Mycobacterium avium complex (MAC) was isolated in 16 (94.1%). Cultures were mainly positive in respiratory specimens (8 bronchoalveolar lavage, 2 sputum, and 1 lung tissue). Nine of 17 patients (52.9%) were deemed colonized whereas 8 (47.1%) were considered infected. In the infected group, isolated pulmonary infection was the most common presentation (n = 5, 62.5%). Two of the 8 infected patients (25%) had MAC bacteremia. Of those with NTMI, MAC was isolated in 6 (75%), MAC and M. abscessus/chelonae in 1 (12.5%), and M. kansasii in 1 (12.5%). Among those with NTMI, 3 were hypoxic (37.5%) and 4 (50%) had sepsis, though only 1 case of sepsis was directly attributable to NTM. Seven infected patients received antimycobacterial therapy. Four patients (50%) died but none were directly attributed to NTM. Diagnosis was often delayed in these patients, with a median of 44 days (range 14–155 days) from time of initial presentation to diagnosis of NTMI. Median time to death from time of NTMI diagnosis was 75 days (range 16–1825 days). CONCLUSION: NTMI, including disseminated infection, was uncommon in a large cohort of HSCT patients. Careful evaluation of positive cultures in these patients is needed to distinguish infection from colonization. High mortality in HSCT patients may not be directly attributable to NTMI, but the presence of NTM may be a predictor of poor outcomes. [Image: see text] DISCLOSURES: All authors: No reported disclosures.