A case report of primary amebic meningoencephalitis in a Chinese adult male.

Primary amebic meningoencephalitis (PAM) is a rare neurological infectious disease with an extremely high mortality rate. This disease is caused by Naegleria fowleri invading the brain, and patient infections are usually linked to exposure to contaminated warm freshwater in summer. This case report describes a 56-year-old adult male, who presented with increased intracranial pressure, headache, blurred vision accompanied by dizziness, periorbital edema, fever (38.5 ℃), nausea, vomiting, and chills. The patient had bathed in a wild hot spring one week prior to symptom onset. In this case, we performed Wright-Giemsa staining on the sediment of the patient’s cerebrospinal fluid (CSF) and detected amoebic trophozoites. Through direct wet mount microscopy, we observed live amoebic trophozoites. We further conducted high-throughput pathogen sequencing on the patient’s CSF sediment. The results also confirmed that the infecting pathogen was Naegleria fowleri. Thus, the patient was diagnosed with PAM, and administered combined anti-infection treatment with amphotericin B (1.5 mg/kg·d) and rifampicin (10 mg/kg·d). The patient’s condition remained in critical condition and ultimately died of terminal cerebral hernia. PAM is a rare and difficult to diagnose infectious disease. We achieved rapid diagnosis of PAM through a combination of traditional microbiological microscopic examination and high-throughput sequencing of pathogenic microorganisms. The case report provides valuable experience for the diagnosis and treatment of PAM.