What is it?
Nipah virus (NiV) belongs to the Paramyxoviridae family of viruses, genus Henipavirus, alongside Hendra virus. Nipah is a zoonotic disease, meaning it passes from animals to humans.
The natural hosts of the virus are fruit bats (also known as flying foxes) of the genus Pteropus. Nipah virus can be spread to people from infected bats, infected pigs or infected people.
Where does it occur?
Nipah virus was first identified in 1999 during an outbreak of illness affecting pig farmers and others living in close contact with pigs. Over 100 human deaths were reported, and over a million pigs were killed to stop the outbreak. No cases of person-to-person spread were reported.
In 2001, there was an outbreak of Nipah virus in people in Bangladesh, and a separate outbreak in a hospital in India. In both countries, person-to-person transmission occurred. Outbreaks in Bangladesh happen nearly every year – with over 300 confirmed cases occurring there from 2001 to 2015.
What does it do?
Nipah virus infection can cause severe, rapidly progressive illness that affects the respiratory system and the central nervous system, including inflammation of the brain (encephalitis). Symptoms begin between 5 and 14 days after infection, and include fever, altered mental state, cough and respiratory problems.
How do we currently prevent infections?
People are advised to avoid contact with ill pigs and bats in countries where Nipah virus is known to occur. They are also advised to avoid drinking raw date palm sap, which can be infected with bodily fluids from bats.
There are currently no vaccines or specific therapeutics against Nipah virus approved for use in humans.