Rare Presentation of Disseminated Nocardiosis With Pulmonary and Neurologic Involvement in an Immunocompetent Patient

Nocardiosis is an opportunistic infection caused by Gram-positive bacilli of the genus Nocardia , which can cause pulmonary, cutaneous and central nervous system infections, especially in immunosuppressed patients. Because it is rare in immunocompetent individuals and its pulmonary clinical and radiologic presentation is nonspecific, diagnosis is difficult. We report a case of disseminated nocardiosis with pulmonary and neurologic manifestations in an immunocompetent patient, highlighting clinical and therapeutic challenges. An 80-year-old male, hypertensive, with hypothyroidism and epilepsy, was admitted on 11/09/24 for revision of total hip arthroplasty and discharged on 22/09. He was readmitted on 30/09 with fever and purulent discharge from the surgical wound, diagnosed as surgical site infection. Bone tissue culture revealed Enterobacter cloacae and Klebsiella pneumoniae , and antibiotic therapy was guided with ciprofloxacin. He developed persistent fever, cough and hemoptysis; chest CT showed a mediastinal mass, and biopsy and bronchoscopy were inconclusive. He was discharged on 09/11 to continue investigation, with ciprofloxacin for prosthetic joint infection. On 07/12, he returned with acute neurologic deficit; cranial CT showed a right occipital abscess. After drainage, Ziehl-Neelsen staining identified microorganisms compatible with Nocardia , and imipenem, linezolid and trimethoprim-sulfamethoxazole (TMP-SMX) were started. On 12/12, Nocardia farcinica was isolated. He maintained neurologic symptoms and abscess with suspected ventriculitis; craniectomy with ventricular shunt was performed on 28/12. New cultures again identified N. farcinica . Linezolid was discontinued after susceptibility results on 08/01/25. After 6 weeks of IV treatment, he showed clinical and radiologic improvement. He was discharged on 05/02 on oral minocycline and TMP-SMX for nocardiosis and ciprofloxacin for prosthetic joint infection, with good response to date. This case illustrates disseminated nocardiosis with pulmonary and CNS involvement in an immunocompetent patient. The insidious course, coinfections and need for multiple interventions demonstrate the diagnostic and therapeutic complexity of this infection. The case is notable for the rarity of the disease in immunocompetent hosts, its diagnostic and therapeutic complexity, effective multidisciplinary approach and good response to antibiotic therapy, making it a valuable example for infectious disease practice.