What is Nipah virus? Key things to know about the disease amid cases in India | South and central Asia

Airports across Asia have been put on alert after India confirmed two cases of the deadly Nipah virus in West Bengal state in the past month.

Thailand, Nepal and Vietnam are among countries controlling airport arrivals over fears of a wider outbreak of the virus, which can spread from animals to humans and has a high mortality rate.

India’s health ministry has confirmed two cases in West Bengal state since December, but said the virus was “contained in a timely manner.”

The government did not give details of infected patients, but said nearly 200 close contacts had been tested and no further outbreaks had been detected.

What is Nipah virus and why is it so deadly?

Nipah virus is primarily transmitted to humans by animals such as pigs and fruit bats, either through direct contact or through their secretions.

It can incubate in the body for a period of four to 14 days. The first symptoms of the virus are often high fever, nausea, vomiting and breathing problems, which can later progress to pneumonia. In severe cases, this causes dangerous swelling of the brain that can lead to neurological symptoms such as drowsiness and seizures.

It is highly contagious between humans and considered by the World Health Organization to be at high risk of epidemic because there is no vaccine. Its mortality rate is high, from 40 to 75%, much more deadly than Covid-19.

When were the previous epidemics?

The disease was first identified in 1998 among pig farmers in Malaysia, where it killed more than 100 people. It owes its name to the village where it was discovered.

Since then, outbreaks have been detected almost every year in Asia, including India, the Philippines, Singapore and Malaysia. It appears regularly in Bangladesh and the first case in India was in 2001 in West Bengal, which borders Bangladesh.

It has been linked to the harvesting of raw sap from dates in Bangladesh, as fruit bats often live in date palms.

In 2018, at least 17 people died from the Nipah virus in the Indian state of Kerala, and two more died in 2023.

How are authorities handling the latest outbreak?

The latest outbreak is significant because these are the first cases detected in West Bengal since 2007.

Indian health authorities said: “Enhanced surveillance, laboratory testing and field investigations were undertaken… resulting in timely containment of cases.” »

So far, no more than two cases have been detected since December. “The situation is under constant monitoring and all necessary public health measures are in place,” India’s health ministry said.

However, other countries have strengthened precautionary screening measures at airports and borders. Thailand, Vietnam and Indonesia have introduced additional checks, including temperature checks and health declarations for passengers arriving from India. Myanmar has advised against all non-essential travel to West Bengal and China has strengthened disease prevention measures in its border areas.

India said reports of a rise in cases were “speculative and incorrect”.