Case Report: Multiple brain abscess-like lesions with concurrent detection of Nocardia amamiensis and Leishmania infantum in cerebrospinal fluid

Abstract

Central nervous system nocardiosis is rare and potentially life-threatening, and human infection due to Nocardia amamiensis has seldom been reported; central nervous system involvement in visceral leishmaniasis is likewise uncommon. We report a 69-year-old man who developed progressive impairment of consciousness and coma after recurrent fever. Brain magnetic resonance imaging revealed multiple abscess-like lesions in both cerebral hemispheres, the cerebellum, and the brainstem, accompanied by acute or subacute cerebral infarctions. The cerebrospinal fluid opening pressure was 300 mmH 2 O. The white blood cell count was 285 × 10 6 /L, with 81.9% polymorphonuclear cells; protein was 1.977 g/L and glucose was 2.34 mmol/L. MetaCAP analysis of cerebrospinal fluid concurrently detected N. amamiensis and L. infantum , and bone marrow smear demonstrated Leishmania amastigotes within macrophages. The patient tested negative for human immunodeficiency virus, and abdominal ultrasonography showed no hepatosplenomegaly. On the available evidence, visceral leishmaniasis was established and central nervous system nocardiosis was strongly suspected. Detection of L. infantum in cerebrospinal fluid supported possible central nervous system involvement, but did not establish a direct contribution to the brain abscess-like lesions. The patient received trimethoprim-sulfamethoxazole, imipenem-cilastatin, amikacin, and liposomal amphotericin B, but his condition continued to deteriorate. He was discharged against medical advice, and follow-up revealed that he had died. This case illustrates that sequencing-based detection is an important clue but cannot replace culture, pathogen-specific polymerase chain reaction, or evidence from lesion tissue.

The authors' abstract, as published at the source. Frontiers in Immunology, 2026 · DOI ↗