Disseminated Mycobacterium Fortuitum Infection in Bilateral Lung Transplant Recipient

Introduction Lower respiratory tract secretions from lung transplant recipients are known on rare occasions to yield a low inoculum of non-tuberculous mycobacteria. However, despite the intense systemic immunosuppression required in these recipients, disseminated mycobacterial disease has rarely been reported. Case Report A 66-year-old male with history of right total knee arthroplasty in 2007 and bilateral lung transplant in 2019 (cytomegalovirus [CMV] donor seropositive/recipient negative) was admitted with two days of fevers, chills, and dyspnea. Immunosuppression therapy included basilixumab induction and maintenance immunosuppression with mycophenolate mofetil, tacrolimus, and prednisone. A CT chest demonstrated patchy opacities in the left lung allograft and right middle lobe with a moderate partially loculated left pleural effusion. A bronchoscopy with bronchoalveolar lavage (BAL) was performed and cultures demonstrated Veillonella parvula, anaerobic gram negative bacilli, and M. fortuitum. Two months earlier, BAL cultures had demonstarted M. fortuitum, but treatment had been deferred at that time as recipient was asymptomatic. Now, with rapid improvement on cephalosporin therapy, treatment for M. fortuitum was again not pursued. The recipient was readmitted one month later with left knee pain, fever, and diarrhea, and was diagnosed with hemarthrosis and CMV colitis. Four weeks later the recipient experienced right knee pain and when joint aspiration demonstrated M. fortuitum he underwent two stage revision at which time intraoperative cultures again yielded M. fortuitum. Following this surgery the recipient then was found to have a chest wall abscess, which when incised also yielded M. fortuitum. Treatment with imipenem and ciprofloxacin for six weeks was initiated, with transition to oral ciprofloxacin for one year. Summary This case illustrates the potential for M. fortuitum pulmonary infections to result in disseminated disease in lung transplant recipients. While rarely reported in the literature, non-tuberculous mycobacterium infections have been associated with bronchiolitis obliterans syndrome and mortality in lung transplant recipients. Dissemination of M. fortuitum is uncommon and prompt recognition is crucial for appropriate source control and antibiotic therapy initiation.