title: Human Hendra virus infection causes acute and relapsing encephalitis.
abstract: OBJECTIVE
  To study the pathology of two cases of human Hendra virus infection, one with no clinical encephalitis and one with relapsing encephalitis.
  
  
  METHODS
  Autopsy tissues were investigated by light microscopy, immunohistochemistry and in situ hybridization.
  
  
  RESULTS
  In the patient with acute pulmonary syndrome but not clinical acute encephalitis, vasculitis was found in the brain, lung, heart and kidney. Occasionally, viral antigens were demonstrated in vascular walls but multinucleated endothelial syncytia were absent. In the lung, there was severe inflammation, necrosis and viral antigens in type II pneumocytes and macrophages. The rare kidney glomerulus showed inflammation and viral antigens in capillary walls and podocytes. Discrete necrotic/vacuolar plaques in the brain parenchyma were associated with antigens and viral RNA. Brain inflammation was mild although CD68(+) microglia/macrophages were significantly increased. Cytoplasmic viral inclusions and antigens and viral RNA in neurones and ependyma suggested viral replication. In the case of relapsing encephalitis, there was severe widespread meningoencephalitis characterized by neuronal loss, macrophages and other inflammatory cells, reactive blood vessels and perivascular cuffing. Antigens and viral RNA were mainly found in neurones. Vasculitis was absent in all the tissues examined.
  
  
  CONCLUSIONS
  The case of acute Hendra virus infection demonstrated evidence of systemic infection and acute encephalitis. The case of relapsing Hendra virus encephalitis showed no signs of extraneural infection but in the brain, extensive inflammation and infected neurones were observed. Hendra virus can cause acute and relapsing encephalitis and the findings suggest that the pathology and pathogenesis are similar to Nipah virus infection.
authors.affiliation: Department of Pathology, University of Malaya, Kuala Lumpur, Malaysia. wongkt@um.edu.my
authors.forename: K T
authors.initials: KT
authors.lastname: Wong
authors.forename: T
authors.initials: T
authors.lastname: Robertson
authors.forename: B B
authors.initials: BB
authors.lastname: Ong
authors.forename: J W
authors.initials: JW
authors.lastname: Chong
authors.forename: K C
authors.initials: KC
authors.lastname: Yaiw
authors.forename: L F
authors.initials: LF
authors.lastname: Wang
authors.forename: A J
authors.initials: AJ
authors.lastname: Ansford
authors.forename: A
authors.initials: A
authors.lastname: Tannenberg
mesh_terms: D000328:Adult; D000956:Antigens, Viral / Q000032:analysis; D001921:Brain / Q000098:blood supply / Q000276:immunology / Q000473:pathology* / Q000821:virology; D003331:Coronary Vessels / Q000473:pathology; D018792:Encephalitis, Viral / Q000276:immunology / Q000473:pathology* / Q000821:virology; D004805:Ependyma / Q000473:pathology / Q000821:virology; D005260:Female; D045404:Hendra Virus / Q000302:isolation & purification; D045464:Henipavirus Infections / Q000276:immunology / Q000473:pathology* / Q000821:virology; D006801:Humans; D007668:Kidney / Q000098:blood supply / Q000473:pathology / Q000821:virology; D008168:Lung / Q000098:blood supply / Q000473:pathology / Q000821:virology; D008264:Macrophages; D008297:Male; D017628:Microglia; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology; D009474:Neurons / Q000473:pathology / Q000821:virology; D012367:RNA, Viral / Q000378:metabolism; D012008:Recurrence; D014657:Vasculitis / Q000276:immunology / Q000473:pathology / Q000821:virology
chemical_list: D000956:Antigens, Viral; D012367:RNA, Viral