|Home Page ILIAD-Tanzania Agro-terrorism ProMED Search Project|
Novel Zoonotic Viral Diseases
Back to Disease Archive Index
Recently discovered zoonotic viral diseases include:
MenangleIn 1997, a new virus of the Paramyxoviridae family was recognized in Australia after mummified and stillborn piglets, some of whom were deformed, greatly impacted production at a commercial breeding facility in New South Wales. In addition, two workers at the piggery developed an influenza-type illness with rash. Investigation revealed that the same virus was not only present in both the animals and humans, but also in fruit bats roosting in the vicinity and not in other wild or domesticated animals.
HendraIn 1994, an outbreak of severe and fatal respiratory disease occurred in Brisbane, Australia, killing 13 out of 20 infected race horses and a horse trainer. In a separate incident 1000 km away in McKay, a farmer and two horses died of encephalitis. The causative agent, another new Paramxyovirus, was eventually proved to the same in both events, though at first the virus was denoted as Australian equine morbillivirus, and only later named Hendra. Scientists believe that Hendra can cause pneumonia in the immediate phase of infection and encephalitis in a latent phase. Again, the fruit bat has been implicated. Research continues. While Hendra is not highly contagious, it can be fatal in both the lung and brain form of the disease.
Australian Bat LyssavirusAs a result of research into the 1994 incidents, and two additional deaths (both cases involving bat rehabilitators), another virus was isolated from fruit bats in 1996. Australian bat lyssavirus is closely kin to the rabies virus, which is not found in Australia as a benefit of strict enforcement of import and quarantine regulations.
NipahBetween October 1998 and April 1999 in Malaysia, a Hendra-like virus was responsible for 229 cases of febrile encephalitis, of which 111 (48%) were fatal. The dominant similarity of the cases was that they were mostly men who worked with pigs, in which there was a concurrent outbreak of disease causing illness and death. At first, Japanese encephalitis was thought to be the cause in both the animals and humans. Further research turned up a new virus, similar but not identical to Hendra. Still again, bats were the suspected hosts.
Collaboration between the University of Malaya and the CSIRO Australian Animal Health Laboratory (AAHL) has led to the characterisation of a new paramyxovirus discovered in Malaysia. Tioman virus, named after a small island off the east coast of the Malayan Peninsula where it was collected, has been characterised as a member of the genus Rubulavirus of the family Paramyxoviridae. It has been established that Tioman virus is related to another virus first identified in Australia in 1997, called Menangle virus.
According to Dr Chua Kaw Bing, from the Medical Microbiology Department of the University of Malaya, Tioman virus was discovered in the course of searching for the animal host of yet another paramyxovirus -- Nipah virus. In 2000, Nipah virus killed 105 people and led to the culling of millions of pigs in Malaysia. Bats were the suspected animal host of Nipah virus, as many bats demonstrated antibodies to the virus. And, indeed, Nipah virus was sucessfully isolated from bat urine samples, proving the connection. During the work, the new virus, which has not yet been implicated in a disease of any species, was found.
The collaborators have now mapped and sequenced the entire genome (approximately 15.4 kb) of Tioman virus. Tioman virus shares up to 80 per cent of its genetic information with its Australian relative, Menangle virus. It is also 50-60 per cent homologous in key protein sequences with a better known paramyxovirus -- human mumps virus, which is itself antigenically related to parainfluenza viruses. The geographic distribution of Tioman virus in bats is as yet unknown.
The web of relationships between newly emerged viruses in Oceana is fascinating. Hendra virus was discovered in Queensland in 1994. Nipah virus, which is closely related, emerged in Malaysia in 1999. In 1997, Menangle virus was identified in New South Wales, and Tioman is a close relative to Menangle virus.