Human Hendra virus infection causes acute and relapsing encephalitis

Area of Science:

• Virology
• Neuropathology
• Infectious Diseases

Background:

• Hendra virus (HeV) is a bat-borne zoonotic virus that can cause severe respiratory and neurological disease in humans.
• Understanding the neuropathology of HeV infection is crucial for developing effective treatments and prevention strategies.

Observation:

• Two human cases of HeV infection were studied post-mortem, one with acute pulmonary syndrome and another with relapsing encephalitis.
• Autopsy tissues were analyzed using light microscopy, immunohistochemistry, and in situ hybridization to identify viral presence and host response.

Findings:

• The acute case showed systemic vasculitis and inflammation in the lungs, kidneys, and brain, with viral antigens detected in various cell types.
• The relapsing encephalitis case presented with severe meningoencephalitis, neuronal loss, and inflammation, with viral RNA and antigens primarily in neurons; vasculitis was absent.
• Both cases demonstrated viral replication in neurons, suggesting a common mechanism for encephalitis.

Implications:

• Hendra virus infection can manifest as acute systemic disease with encephalitis or as isolated relapsing encephalitis.
• The distinct pathological findings highlight the diverse clinical presentations of HeV infection.
• The observed similarities in pathogenesis to Nipah virus infection warrant further comparative studies.