To report a case of an immunocompetent young adult male patient diagnosed with intracranial Aspergillus flavus infection， and to investigate the clinical features of this disease and related experience in diagnosis and treatment.A retrospective analysis was performed for the clinical data of a patient who had the initial presentation of high fever and headache and then progressed to meningoencephalitis， and the results of cerebrospinal fluid （CSF） metagenomic next-generation sequencing （mNGS） and treatment outcomes were summarized.The patient had an acute onset， with no response to empirical anti-infective therapy in the incipient stage， and then he gradually developed disturbance of consciousness and meningeal irritation sign. CSF analysis showed inflammatory changes， while conventional pathogen tests yielded negative results， and mNGS detected 27 specific sequences of Aspergillus flavus. The symptoms of the patient was significantly improved after antifungal therapy with voriconazole， with no recurrence after follow-up for 3 months.For unexplained central nervous system infections， especially those with negative results from conventional tests， mNGS can improve the detection rate of rare pathogens（e.g.，Aspergillus flavus）. Early diagnosis and targeted antifungal therapy are crucial for improving prognosis. This case highlights that invasive fungal infections should be considered even in immunocompetent individuals.
Aspergillus flavus