Zoonotic paramyxoviruses

This chapter focuses on recently emergent paramyxoviruses that are associated with zoonotic disease, Hendra virus (HeV), Nipah virus (NiV), and Menangle virus (MeV). Molecular biological studies have made substantial contributions to the characterization of recently emergent zoonotic paramyxoviruses. As for other paramyxoviruses, the NiV surface glycoproteins are the primary targets for neutralizing antibodies. The conservation of most of the structurally important amino acids suggests that the attachment proteins of HeV and NiV would have structures that are very similar to the structure proposed for the attachment proteins of other paramyxoviruses. The development or characterization of animal models to study henipavirus infections is critical for understanding their pathogenesis and for development of therapeutics or vaccines. The chapter describes the pathogenesis and immune responses of human infections for each virus. Traditional techniques of virus isolation in cell culture, electron microscopy, enzyme-linked immunosorbent assay-based serology, neutralization assays, and immunohistochemical (IHC) techniques have been employed in the diagnosis of the zoonotic paramyxoviruses. NiV and HeV are internationally classified as biosafety level or biosecurity level 4 (BSL-4) agents; thus, clinical specimens suspected to be infected with these agents must be handled with caution. Pig farmers in areas in which NiV may be endemic should be educated regarding the features of Nipah encephalitis in pigs and to report any unusual disease. Since transmission is possible without close contact with pigs, exposure to potentially infected animals should be completely avoided, if possible. Persons handling pigs or their excreta should wear protective equipment such as gloves and masks.