After two people died from the uncommon and fatal Nipah virus, Indian’s southern of Kerala is taking action to control an epidemic of the virus, closing schools and conducting hundreds of tests to stop its spread.

This is the state’s fourth outbreak. The first epidemic broke out in 2018, claiming 21 lives, with further outbreaks in 2019 and 2021.

There is no vaccination for the virus, and there are only supportive treatments available.

Kerala's health minister, Veena George, told reporters on Wednesday that more than 700 people have been identified as close contacts and are undergoing virus testing.

She said that 77 of them were deemed to be "high risk" and that they had been urged to stay at home and keep an eye on their health.

But what is the Nipah virus and its symptoms?

What is the Nipah virus?

The Nipah virus is a zoonotic virus that can be transmitted to humans from animals, with fruit bats being the natural hosts according to the World Health Organisation (WHO).

Because of its potential for an epidemic or a pandemic, the Nipah infection is one of the priority diseases on the WHO R&D Blueprint. However, there have been no cases in Europe.

Direct contact with infected humans, animals, or their bodily fluids, as well as intake or handling of contaminated products, are the two main ways that Nipah is spread. Transmissions from mothers to children have not been seen. Nevertheless, a test on animals proved the possibility.

Is this a new virus?

It’s not a new virus.

Following the discovery of the virus during an outbreak of severe encephalitis in Nipah, Malaysia, cases of the Nipah virus were first documented in humans in 1998, with cases also being recorded in Singapore.

Later, outbreaks occurred in regions of North East India and, since 2001, virtually yearly in particular Bangladeshi districts. Infections with the henipavirus, thought to have been brought on by the Nipah virus or a virus similar to it, have also been reported in the Philippines.

In addition to being found in 23 species of bats throughout Asia, as well as in bats in Ghana and Madagascar, the Nipah virus has been isolated from the urine of bats in Malaysia. However, Nipah virus infections in humans have not been reported outside of South and Southeast Asia, and the majority of outbreaks have taken place in rural or semi-rural areas.

What are the symptoms?

Individuals with symptoms may display anything from minor respiratory discomfort to severe respiratory distress or encephalitis. Atypical pneumonia and serious respiratory issues, such as acute respiratory distress, are more common in those with the NiV-B type of the virus.

According to the Disease Control and Prevention (CDC), symptoms frequently start with headaches and tiredness but swiftly develop into a coma within days.

The infection has a mortality rate between 40% and 75% and the usual treatment is to provide supportive care, with no drug treatment or vaccine currently available.