Nipah virus (NiV) is a newly emerging zoonotic infectious disease. The natural hosts of the virus are fruit bats of the Pteropodidae family, Pteropus genus, however pigs act as the amplifying host for the virus, meaning it can be more readily transmitted to humans from pigs. NiV is a RNA virus of the family Paramyxoviridae, genus Henipavirus.
- Nipah infection is listed in the World Organisation for Animal Health (OIE) Terrestrial Animal Health Code and must be reported to the OIE (OIE Terrestrial Animal Health Code).
There is evidence of Nipah infection among several other species of domestic animals including dogs, cats, goats, and horses.
Clinical signs (pigs):
- Respiratory and neurological syndrome, known as “barking pig syndrome”
- Morbidity is usually high but mortality is low
- Rapid laboured breathing
- Very harsh explosive cough
- In sows disease may be more pronounced with severe breathing difficulties
- Mucopurulent discharges from the nose
Human infection with Nipah virus is associated with encephalitis. Disease typically presents as fever and headache, followed by drowsiness and disorientation, which can rapidly progress to coma. During the 1998-99 Nipah outbreak, 40% of patients admitted with serious nervous disease died. Respiratory signs may be observed during the early part of the infection, and a significant proportion of patients showing severe neurological signs also display pulmonary signs. Latent Nipah virus infections have been reported with subsequent viral reactivation leading to death.
Transmission of Nipah virus between humans, pigs and bats is through direct contact with secretions and excretions.
The disease ﬁrst appeared in domestic pigs in Malaysia and Singapore in 1998 and 1999. Ten countries (Australia, Bangladesh, Cambodia, China, India, Indonesia, Madagascar, Papua New Guinea, Taiwan and Thailand) have reported Henipavirus (Nipah or the closely related Hendra virus) outbreaks or are at risk based on serological evidence or molecular detection in Pteropus bats (CDC, USA, 2018). Since the initial outbreak it has primarily affected humans in South and Southeast Asia (Malaysia, Singapore, Bangladesh and India) with devastating consequences.
Impact for Society – what are we doing?
A grant worth £2,359,553 was awarded to The Pirbright Institute’s Dr Simon Graham to lead an international team developing an inexpensive, safe and effective vaccine to protect pigs against Nipah virus. The project ‘A Nipah vaccine to eliminate porcine reservoirs and safeguard human health’ was funded by UK Department of Health and Social Care through the Innovate UK SBRI Vaccines for Global Epidemics – Clinical competition.