The outbreak of Nipah virus in Malaysia in 1999 created history in the category of new emerging diseases. It caused major losses, both in animal and human lives and to trade, and created a significant set back to the swine sector of the animal industry in Malaysia. The control and eradication of Nipah virus was an example in international cooperation with prompt participation and inputs from many countries.
While retrospective epidemiological investigations now indicate that the disease may have caused mortality in pigs and humans at least one year earlier, the discovery and identification of the infective agent in March 1999 was the turning point in controlling the major outbreak which began in late 1998. The Government of Malaysia acted very boldly in eliminating the carrier animals at the infected foci in a number of locations across the country. The culling of infected pigs has successfully stopped the infection of humans in its tracks, after 257 people were registered as infected with this virus. The removal of pigs during the outbreak period, and subsequent mopping up and surveillance operations affected 1 006 farmers and 1.2 million pigs. The effect on the loss of human lives and the economies of these swine farmers as well as others in related activities will remain for a long time.
The outbreak of a new disease and the discovery of a new infective agent like Nipah virus has created new experiences and expertise. The identification of species of fruit bats as the probable natural host of Nipah virus and the related Hendra virus raises the possibility that these or other novel paramyxoviruses may be more prevalent than we think, given the occurrence of the fruit bat species in many countries in the region. This manual is the result of the experience of many scientists and experts who had been involved in the initial control programme and the subsequent scientific investigations on this disease and the infective agent. It should serve as an effective guide to other scientists, diagnosticians, laboratory personnel, field operatives and others who are interested in this subject.
Nipah virus is a zoonotic agent that has caused death in animals and humans. In Malaysia, the effective carrier was pigs, and transfer to humans was through direct contact with infected pigs. Although the virus characteristics do not allow the disease to spread from human to human and become pandemic, the safety procedures in handling infected animals cannot be over-emphasized.
In mid-2001, the Office International des Epizooties (OIE) declared the Malaysian pig population officially free of Nipah virus infection. I would like to take the opportunity to thank all the scientists and personnel from all agencies and countries involved in the control of the Nipah virus disease, without whose efforts the disease could not have been effectively controlled in such a short time. My sincere congratulations are directed to Hume Field and the team of scientists who have successfully put together the materials in this manual.
MOHD NORDIN MOHD NOR
Department of Veterinary Services
Kuala Lumpur, Malaysia
10 October 2001