Nipah Virus

Also known as Porcine Respiratory and Neurological syndrome — Barking Pig syndrome

Introduction

Nipah virus is of the family Paramyxoviridae. It is a recently emerged disease and has only been present since 1999.

The origins of Nipah virus is unknown, but the reservoir host is thought to be fruit bats. The disease has been seen only in South East Asia currently and it is named after the Malaysian village where it was first noted. 

Nipah virus effects pigs and has caused death in pigs and over two hundred humans, therefore making it a zoonotic disease. The disease is transmitted from excrement, semen, urine or saliva of bats and it is thought that virus shedding from the bats increases in times of stress, such as destruction of their habitat or illness. Pigs are infected with the disease causing a severe respiratory and neurological signs in these animals. In pigs, the disease is transmitted by aerosol from coughing. Humans can contract the disease from direct contact with pigs and thus most people that have died from the disease are farmers, abattoir workers or veterinarians. More unneccessary deaths occurred in humans when infected pigs were shot (as authorities thought the disease was spread by insects) and humans were exposed to pig blood.

It is antigenically related to Hendra virus, with which it shares ~90% amino acid homology. Both viruses have been classified in a new genus, Henipavirus, in the subfamily Paramyxovirinae, family Paramyxoviridae.

Clinical Signs

Signs are mainly respiratory in pigs and include coughing, increased respiratory rate, dyspnoea and weakness. In humans the disease is similar in some respects to influenza, with muscle pain and fever. Encephalitis may also occur.

Diagnosis

Diagnosis can be achieved by serology, histopathology, PCR and virus isolation.

Control

It is important to establish surveillance systems for detection of the disease.

A vaccine is being developed for pigs, which may also have some value in humans too.

References

Bridger, J and Russell, P (2007) Virology Study Guide, Royal Veterinary College

Reynes J.M., Counor D., Ong S., Faure C., Seng V., Molia S., Walston J., Georges-Courbot M.C., Deubel V., Sarthou J.L. (2005). Nipah Virus in Lyle's Flying Foxes, Cambodia; Emerging infectious diseases, 11 (7) : 1042-1047.

Straw, B.E. and Taylor, D.J. (2006) Disease of Swine Wiley-Blackwell