Hendra (equine morbillivirus)

Hendra has been recognized in Australia as a new zoonotic disease of horses since 1994/5 and subsequent work has shown that the viral agent is endemic in certain species of fruit bat. The Hendra virus is the type species of a new genus within the sub-family Paramyxovirinae, which also contains anoth er newly identified zoonotic bat virus, namely Nipah. It is assumed that co ntact with bats has led to the Hendra virus being transferred to horses on each of the three separate incidents that have been reported in the last fi ve years. No evidence has been found for widespread subclinical infection o f horses. Infected horses can develop a severe and often fatal respiratory disease ch aracterized by dyspnoea, vascular endothelial damage and pulmonary oedema. Nervous signs may also occur. Fatal respiratory disease has been seen in ca ts and guinea pigs following experimentally induced infections. Transmissio n of the virus from horses to other horses or man seems to have taken place , but very close contact was required. Three human cases have been recogniz ed, all in association with equine cases. There have been two human fatalit ies, one due to respiratory failure and the other from a delayed-onset ence phalitis. A number of diagnostic methods have been developed, but great car e must be taken in obtaining samples from suspected cases. (C) 2000 Harcour t Publishers Ltd.