Spondylodiscitis by Mycobacterium avium in an Immunocompromised Patient: Diagnostic and Therapeutic Challenges.

The Mycobacterium avium complex (MAC), consisting mainly of M. avium and Mycobacterium intracellulare, is a group of nontuberculous mycobacteria found in water, soil, and aerosols. While generally low in pathogenicity for immunocompetent individuals, MAC can cause severe infections in immunocompromised patients, such as those with Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome, organ transplants, or on immunosuppressive therapy. Although pulmonary infections are most common, extrapulmonary infections like spondylodiscitis are becoming important diagnostic and therapeutic challenges. This report describes a case of M. avium spondylodiscitis in a 79-year-old woman with a history of myelofibrosis, treated with ruxolitinib, and previous M. avium infection. The patient presented with fever and exacerbated bone pain, particularly in the lumbar spine and sacroiliac joints. Diagnostic imaging and microbiological analysis confirmed the diagnosis of spondylodiscitis caused by M. avium. Despite the initiation of appropriate antimicrobial therapy, including azithromycin, rifampicin, ethambutol, and amikacin, the patient developed severe acute respiratory failure and ultimately succumbed to respiratory distress, likely secondary to pulmonary edema from the infection. This case underscores the rarity and diagnostic complexity of M. avium-induced spondylodiscitis, particularly in immunocompromised patients. It highlights the critical need for early clinical suspicion, microbiological confirmation, and a multidisciplinary approach to treatment, including both pharmacological and surgical interventions when necessary.