Nipah virus under the electron microscope.
Fighting Nipah virus
In 1998-99, an outbreak of a new virus, now called the Nipah virus, killed more than 100 people and thousands of pigs in Malaysia.
19 January 2009 | Updated 14 October 2011
A new virus
The outbreak in Malaysia
The first people infected with Nipah virus are believed to have been pig farm workers living near Ipoh, Malaysia's third biggest city, in January 1997. These cases were initially diagnosed as Japanese encephalitis (JE), a virus which causes neurological symptoms in humans. JE is endemic in Malaysia.
By late 1998, about ten workers from the villages of Tambun, Ulu Piah and Ampang, near Ipoh, had also died. As a result, a Malaysian task force was formed to investigate. Through movement of infected pigs, the disease reached Sikamat, about 60 kilometres south of the Malaysian capital, Kuala Lumpur, December 1998.
By March 1999, the disease spread to the southern Malaysian, major pig-producing, area of Bukit Pelandok, with many more human cases ocurring.
AAHL provided the Nipah virus test to other Southeast Asian countries, enabling surveys to be conducted throughout the region.
The outbreak resulted in 265 confirmed human cases with 105 fatalities.
A new virus
Nipah virus is a new member of the paramyxovirus family. It was named after one of the Malaysian villages affected, Sungai Nipah.
Dr Chua Kaw Bing from the University of Malaya discovered the new virus in March 1999.
Nipah virus is related to, but distinct from, the Hendra virus, another paramyxovirus first isolated in 1994 in Hendra in Brisbane, Australia. The two viruses form a new genus, Henipavirus, in the paramyxovirus family.
Genetic characterisation shows the viruses vary by about 20 per cent. Their behaviour is also different, in terms of the species they infect and the way they seem to be transmitted. Hendra virus does not transmit readily between animals other than flying foxes, while Nipah virus appears to be easily transmitted between pigs and possibly to other animals.
Dr Peter Daniels and Dr John White from CSIRO's Australian Animal Health Laboratory (AAHL), as part of an International Task Force, travelled to Malaysia in March 1999, joining a US Centers for Disease Control and Prevention (CDC) team.
Dr Daniels worked with the Malaysian Department of Veterinary Services, conducting animal post mortems and collecting animal blood samples for testing at AAHL in Geelong, Victoria, Australia. AAHL staff also played a substantial training role in training Malaysian animal health staff to work safely with this dangerous virus on farms and in the laboratory.
Dr Daniels also assisted the Malaysian Veterinary Services Department in designing the national surveillance and eradication program for Nipah virus in livestock, under which all pig farms in Peninsula Malaysia were sampled for laboratory testing.
Dr White worked with the Veterinary Research Institute in Ipoh to develop a blood test to show if animals had been exposed to the virus.
In Geelong, AAHL scientists undertook transmission experiments with pigs to determine how they pass the virus to other pigs and to people. The scientific team used a range of techniques including electron microscopy, histology and genetic sequencing to research the virus.