India's Nipah virus outbreak: what do we know so far?

NEW DELHI, India — Authorities in India are scrambling to contain a rare outbreak of Nipah, a virus spread from animals to humans that causes deadly fever with a high mortality rate.

Here is a look at what we know so far:

What is the Nipah virus?

The first Nipah outbreak was recorded in 1998 after the virus spread among pig farmers in Malaysia.

The virus is named after the village where it was discovered.

Outbreaks are rare but Nipah has been listed by the World Health Organization (WHO) -- alongside Ebola, Zika and Covid-19 -- as one of several diseases deserving of priority research for their potential to cause a global epidemic.

Nipah usually spreads to humans from animals or through contaminated food, but it can also be transmitted directly between people.

Fruit bats are the natural carriers of the virus and have been identified as the most likely cause of subsequent outbreaks.

Symptoms include intense fever, vomiting and a respiratory infection, but severe cases can involve seizures and brain inflammation that results in a coma.

There is no vaccine for Nipah.

Patients have a mortality rate of between 40 and 75 percent depending on the public health response to the virus, the WHO says.

What has happened during previous outbreaks?

The first Nipah outbreak killed more than 100 people in Malaysia and prompted the culling of one million pigs in an effort to contain the virus.

It also spread to Singapore, with 11 cases and one death among slaughterhouse workers who came into contact with pigs imported from Malaysia.

Since then, the disease has mainly been recorded in Bangladesh and India, with both countries reporting their first outbreaks in 2001.

Bangladesh has borne the brunt in recent years, with more than 100