Introduction: Rabies is a fatal viral zoonosis. It typically manifests as furious or paralytic encephalomyelitis. Diagnosis is challenging, especially with atypical presentations, low viral loads, or immunocompromise. HIV co-infection may further obscure the clinical picture. Case Presentation: A 53-year-old man with well-controlled HIV presented with dizziness, fever, and headache, then rapidly developed right hemiparesis, dysarthria, and behavioral changes. On day 3, he acutely deteriorated, developing quadriplegia, dysphagia, and mutism. Repeat CSF mNGS detected 48 rabies virus reads; reanalysis of the initial CSF sample revealed only 9. Conclusion: Early rabies diagnosis may fail when viral load falls below the detection limit of targeted assays such as tNGS. Even well-controlled HIV infection can predispose to atypical, rapidly progressive paralytic rabies. For acute encephalitis of unknown cause, clinicians should suspect rabies and repeat CSF testing using highly sensitive methods if initial tests are negative. Keywords: rabies, next-generation sequencing, HIV, diagnosis, encephalitis
Yu et al. (Fri,) studied this question.