Background: Mpox, formerly known as monkeypox, is an infectious disease caused by the mpox virus. Systemic involvement is rare and mpox-associated meningoencephalitis is an uncommon clinical presentation. Because mpox-associated meningoencephalitis is characterized by nonspecific clinical and incidental imaging findings, the disease is difficult to diagnose.

Case summary: We present a case of fatal mpox-associated meningoencephalitis with negative polymerase chain reaction in cerebrospinal fluid (CSF) diagnosed at autopsy. A young immunocompetent patient with no significant medical history initially presented with genital mpox infection. Within 48 hours, he showed neurologic involvement requiring orotracheal intubation. His condition deteriorated rapidly, progressing to cerebral edema and brain death consistent with meningoencephalitis. Despite negative testing for mpox virus in CSF, the diagnosis was confirmed posthumously by autopsy, where histological examination revealed the presence of mpox virus in brain tissue.

Conclusions: Mpox-associated meningoencephalitis should be considered as a potential diagnosis even in the absence of the mpox virus genome in CSF.

Keywords: diagnostic; encephalitis; histology; monkeypox; nonimmunocompromised.

Copyright © 2025 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of the Society of Critical Care Medicine.

背景：背景:

Mpox（以前称为猴痘）是由Mpox病毒引起的一种传染病。全身受累的情况较为罕见，而与Mpox相关的脑膜脑炎是一种不常见的临床表现。由于Mpox相关性脑膜脑炎具有非特异性的临床症状和偶然的影像学发现，因此该病很难被诊断。

病例摘要：

我们报道了一例致命的Mpox相关性脑膜脑炎案例，在脑脊液（CSF）中聚合酶链反应检测为阴性，最终通过尸检确诊。一位年轻的免疫功能正常的患者，没有明显的病史，最初表现为生殖器Mpox感染。在48小时内，他出现了神经系统症状，需要气管插管治疗。病情迅速恶化，进展至脑水肿和脑死亡，符合脑膜脑炎的诊断标准。尽管CSF中检测不到Mpox病毒，但在尸检时通过组织学检查发现大脑组织中有Mpox病毒的存在，从而确认了该诊断。

结论：

即使在脑脊液中没有检测到Mpox病毒基因组的情况下，也应考虑将Mpox相关性脑膜脑炎作为潜在的诊断。

关键词：

诊断；脑炎；组织学；猴痘；非免疫缺陷。