Nanopore Sequencing-Enabled Early Diagnosis of Postoperative Fungal Discitis Caused by Aspergillus fumigatus in an Immunocompetent Patient: A Case Report and Review of Literature

Postoperative spondylodiscitis is an uncommon complication of spinal surgery and is most often bacterial in origin. Fungal discitis caused by Aspergillus fumigatus is exceedingly rare in immunocompetent patients and presents a major diagnostic challenge owing to its indolent course and the low yield of conventional cultures. An 85-year-old immunocompetent man underwent L1–L2 and far-lateral L2–L3 lumbar discectomy and developed progressive back pain with rising C-reactive protein levels 2 weeks postoperatively. Magnetic resonance imaging was suggestive of spondylodiscitis, but computed tomography-guided biopsy and bacterial and fungal cultures were negative. The patient showed transient improvement on empirical broad-spectrum antibiotics but subsequently deteriorated, necessitating surgical re-exploration with bilateral L1–L2 pedicle screw fixation and transforaminal lumbar interbody fusion. Intraoperative samples analyzed using nanopore sequencing identified A. fumigatus within 24 hours, and this was subsequently confirmed on fungal culture. Targeted antifungal therapy with intravenous amphotericin B followed by oral voriconazole resulted in sustained clinical, biochemical, and radiological improvement. Fungal discitis should be considered in non-resolving, culture-negative postoperative spondylodiscitis. Nanopore sequencing enables rapid pathogen identification and may facilitate early targeted therapy, potentially limiting structural damage and improving outcomes. To the best of our knowledge, this is the third reported case of postoperative A. fumigatus spondylodiscitis in an immunocompetent patient and the first to be diagnosed by nanopore sequencing.