Leptospirosis is a zoonotic spirochaetal infection with a broad clinical spectrum, ranging from mild anicteric illness to severe systemic disease. Central nervous system (CNS) involvement, particularly aseptic meningitis, is an underrecognized and diagnostically challenging manifestation, especially when isolated from systemic signs. We report a case of a 43-year-old male with a history of CNS demyelinating disease, treated with rituximab, who presented with a one-month history of recurrent fever, headache, and painful lower extremity nodules. He also experienced unintentional weight loss. After a thorough infectious workup, cerebrospinal fluid (CSF) analysis, including broad-range PCR and the Karius test, confirmed the diagnosis of leptospirosis caused by Leptospira noguchii. He was initially treated with intravenous ceftriaxone and oral doxycycline for 7 days, resulting in symptomatic improvement. However, symptoms recurred two weeks later, with repeat CSF analysis revealing persistent pleocytosis, necessitating a prolonged course of treatment. This case underscores the limitations of conventional testing in immunocompromised hosts and highlights the critical role of advanced molecular diagnostics for early and accurate detection of neuroleptospirosis. Clinicians should maintain high suspicion for leptospiral meningitis in appropriate clinical contexts to improve outcomes through timely intervention.

Cervicofacial actinomycosis is a well-recognized infectious disease caused by Actinomyces, a Gram-positive filamentous bacterium. In contrast, Nocardia, a morphologically similar, hyphae-forming organism, is an exceedingly rare cause of cervicofacial abscesses, and even more uncommon associated osteomyelitis of mandible. We present such a case involving a kidney transplant recipient who presented with opioid-induced constipation, along with left jaw pain and swelling. CT scan of the soft tissue in the neck revealed a complex cervicofacial abscess with enhancement of underlying mandible. Culture growth and RNA sequencing of USG-guided aspirate identified a Nocardia species closely related to N. beijingensis/exalbida. The patient initially received broad-spectrum antibiotics, including ceftriaxone, imipenem, and trimethoprim-sulfamethoxazole (TMP-SMX). Imipenem was later discontinued in view of new-onset unexplained encephalopathy and replaced with linezolid, which was subsequently switched to minocycline following thrombocytopenia development. Minocycline therapy was intended for a total of 12 months. TMP-SMX was avoided long-term due to avoid nephrotoxicity risk in kidney transplant patients. On six-month follow-up, the patient showed clinical and radiological improvement; minocycline was discontinued after additional six months. This case highlights the importance of considering Nocardia as a differential diagnosis in immunosuppressed patients presenting with cervicofacial symptoms, especially following orofacial surgery or trauma. Early recognition, prompt diagnosis, and appropriate antibiotic therapy with adequate bone penetration seem crucial for optimal management and may help avoid the need for surgical intervention.