(574) A Rare Case of Disseminated Monkeypox With Encephalitis

Introduction: Monkeypox is a viral zoonotic disease in the Poxviridae family. Transmission is via infected animals or close contact with infected persons. Cases present with lymphadenopathy and maculopapular to vesiculopustular skin and mucosal eruptions. Rare cases of nervous system involvement of monkeypox including encephalitis, seizure and stroke have also been seen with other Orthopoxviruses.

Description: 37 year old male with AIDS (CD4 count 42 cells/mm³), MSM and recent completion of syphilis treatment presented with one week of disseminated non-painful umbilicated large papules to nodules on his trunk, extremities, face, lips, gums and large exophytic verrucous lesions at anal verge. Over two weeks lesions grew larger, pustular and spread to eyelids without ocular involvement. Lesions from lip and anus both tested positive for monkeypox by PCR.
He developed peritonitis with bowel perforation requiring total colectomy complicated by persistent thrombocytopenia and hematemesis with suspected diffuse GI tract involvement of monkeypox. He remained alert and oriented but on post-op day (POD) 2 became altered requiring intubation. POD 3 he had two seizure-like episodes with diffuse slowing and left temporal prominence on EEG. He remained hemodynamically stable but comatose. CT head with mild cerebral edema and MRI showed restricted diffusion in bilateral thalami to the midbrain and pons along the spinothalamic tract and upper cortex of bilateral frontal lobes consistent with viral encephalitis.
In addition to starting empiric coverage and HAART, a course of IV acyclovir was completed for positive HSV. He tested negative for cryptococcus, gonorrhea, chlamydia, toxoplasmosis and CMV. After the diagnosis of monkeypox was confirmed, IV Tecovirimat, Vaccinia IVIG and steroids were started. Treatment is ongoing and neurologic status remains poor.

Discussion: In 2022, the monkeypox virus was declared a public health emergency by the WHO. Cases primarily affect men who have sex with men (MSM) typically with limited involvement to the genital and anal regions. Monkeypox encephalitis has an estimated 2% prevalence often seen with CD4 counts < 100 cells/mm³. We present a rare case of monkeypox in an immunocompromised individual with confluent GI tract involvement progressing to viral encephalitis.