Within the past decade a number of new zoonotic paramyxoviruses emerged from flying foxes to cause serious disease outbreaks in man and livestock.

Hendra virus was the cause of fatal infections of horses and man in Australia in 1994, 1999 and 2004.

Nipah virus caused encephalitis in humans both in Malaysia in 1998/99, following silent spread of the virus in the pig population, and in Bangladesh from 2001 to 2004 probably as a result of direct bat to human transmission and spread within the human population.

Hendra and Nipah viruses are highly pathogenic in humans with case fatality rates of 40% to 70%.

Their genetic constitution, virulence and wide host range make them unique paramyxoviruses and they have been given Biosecurity Level 4 status in a new genus Henipavirus within the family Paramyxoviridae.

References

 Eaton BT, Broder CC, Wang LF. Hendra and Nipah viruses: pathogenesis and therapeutics. Curr Mol Med. 2005 Dec;5(8):805-16. PMID: #16375714