Zoonotic paramyxoviruses
Three zoonotic paramyxoviruses (Hendra, Menangle, and Nipah viruses) emerged during 1994-2004 and all these viruses have a fruit bat reservoir. Humans are infected by close contact with infected pigs or horses. Hendra virus infection was described in Australia in 1994, where it caused acute, fatal respiratory disease in horses and humans. Menangle virus was also described in Australia in 1996 where it caused reproductive disorders in pigs and an influenza-like disease in humans. Nipah virus was detected in 1998 in Malaysia, when it caused severe disease with respiratory and neurologic symptoms among pigs and encephalitis with a 40 % death in humans in close contact with pigs. The incidence of Nipah virus has later been reported from India and Bangladesh also.
Hendra and Nipah viruses are type species of a new genus Henipavirus within the subfamily Paramyxovirinae. Henipaviruses along with Australian bat Lyssavirus are the three viruses newly identified encephalitogenic zoonotic viruses which are transmitted from fruit bats of the genus Pteropus.