Coinfection by Mycobacterium tuberculosis and Rhodococcus equi in advanced HIV

Abstract

A 28-year-old man with HIV (diagnosed eight years prior, last CD4 count 23 cells/mm3) and prior tuberculosis (cured, then confirmedly reinfected with treatment default) presented with cachexia, diarrhea, chest pain, and tachypnea with increased work of breathing that required orotracheal intubation. Admission chest CT showed extensive bilateral consolidations with air bronchograms, suggestive of previous mycobacterial infection and/or possible new bacterial infection. Initially managed as sepsis, blood cultures grew Rhodococcus equi (four samples). Molecular testing confirmed Mycobacterium tuberculosis in sputum and tracheal aspirate, establishing coinfection and exceeding the similarities in acid-fast staining, clinical, and radiological findings between the two organisms. Treatment included antituberculosis therapy associated with clarithromycin and vancomycin (14 days). The patient achieved complete clinical improvement with partial radiological resolution (residual cavitations). He was discharged after 25 days, but was lost to follow-up and died three months later from probable septic shock. This report highlights a rare M. tuberculosis/R. equi coinfection in an immunosuppressed patient, emphasizing diagnostic challenges and the importance of therapeutic adherence in advanced HIV.