Importance B virus, or herpes B infection, is a rare zoonotic disease acquired through contact with macaques. Ocular involvement of B virus is rarely documented in literature, yet it may progress rapidly and result in blindness if not recognized promptly. Objective To present a unique case of human B virus infection with clinical features including severe central nervous system dysfunction and bilateral panuveitis in a patient with history of monkey bite. Design, Setting, and Participants This descriptive, qualitative report examined a unique case of B virus infection treated at a tertiary center in Hong Kong with in-depth analysis of clinical presentation and treatment response. The study was conducted in September 2025 and analyses were performed in November 2025. Main Outcomes and Measures Clinical features of B virus–related uveitis and chorioretinitis were described in detail. Serial fundus photographs were used to monitor disease progression and response to treatment. Results The diagnosis of B virus meningoencephalitis with ocular involvement was confirmed with polymerase chain reaction analysis of cerebrospinal fluid and vitreous fluid. Conclusions and Relevance Ocular features of B virus infection of the reported case include anterior uveitis, vitritis, multifocal chorioretinitis, vasculitis, and optic nerve involvement. Treatment included systemic and intravitreal ganciclovir, and corticosteroids for inflammation control. Timely diagnosis and initiation of antiviral therapy are crucial for controlling B virus infection. Additional studies are required to better determine the clinical features and presentation of B virus infection in different patient demographics to reduce disease-related blindness and improve survival.
Wong et al. (2026) studied this question.