Background: Treatment of Mycobacterium abscessus infection is difficult and typically requires many months of combination antimicrobial therapy. The epidemiology, treatment, and clinical outcomes of M. abscessus infection in solid organ transplant (SOT) recipients are not well established.
Methods: We retrospectively collected clinical data from all SOT recipients with positive cultures for M. abscessus obtained at a single center from 1/2012 through 2/2015. For patients who received antimicrobial therapy, we analyzed baseline demographics and potential risk factors for infection, sites of infection, antimicrobial treatment courses and toxicities, and clinical outcomes. The follow-up period included up to two years after the date of the first positive culture.
Results: We identified 122 SOT recipients with incident M. abscessus colonization or infection. 82 (67%) patients received antimicrobial therapy, including 72 lung and 9 heart transplant recipients. Median duration from transplant to first positive culture was 59 days (interquartile range [IQR], 24-141 days).
The majority of the 82 treated patients had isolated pulmonary disease (n=48, 59%), but 34 (41%) patients had extrapulmonary infections (Figure 1). Median duration of antimicrobial therapy was 170 days (IQR, 79-249 days). The predominant initial treatment regimen for patients with pulmonary disease alone included oral azithromycin, inhaled amikacin, and either intravenous (IV) imipenem or cefoxitin (n=34, 71%). For patients with extrapulmonary disease, the most common initial regimen included oral azithromycin, IV tigecycline, and either IV imipenem or cefoxitin (n=13, 38%) (Figure 2). 55 (67%) patients experienced antibiotic toxicities, of which 68% were therapy-limiting. The most common toxicities were gastrointestinal symptoms (n=41, 50%) and renal insufficiency (n=17, 21%). 45 (55%) patients stopped therapy due to presumed cure, but 38 (46%) patients died within two years of diagnosis.
Conclusion: M. abscessus infection after SOT is associated with high morbidity and mortality. Most patients in our study received prolonged, 3-drug antimicrobial regimens and experienced antibiotic-associated toxicities. Nearly half of all treated patients died.
A. W. Baker,
J. H. Saullo, None
S. Arif, None
D. Anderson, None
B. D. Alexander, Viamet Pharmaceuticals, Inc.: Investigator , Research support
C. R. Wolfe, None
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