Some Asian airports screen passengers after outbreak in India

An outbreak of the deadly Nipah virus in India’s West Bengal state has stoked concerns in parts of Asia, with airports stepping up screening measures.

Thailand has started screening passengers at three airports receiving flights from West Bengal. Nepal has also started screening arrivals at Kathmandu airport and other land border points with India.

Earlier this month, five healthcare workers in West Bengal contracted the virus, with one in critical condition. About 110 people who had been in contact with them have been quarantined.

The virus can spread from animals to humans. It has a high mortality rate, ranging from 40% to 75%, because there is no vaccine or drug to treat it.

Nipah virus can be transmitted to humans from animals such as pigs and fruit bats. It can also be spread from person to person through contaminated food.

The World Health Organization lists Nipah virus among its top ten priority diseases, along with pathogens such as Covid-19 and Zika virus, because of its potential to cause epidemics.

The incubation period is 4 to 14 days.

People infected with the virus can show a wide range of symptoms and sometimes no symptoms at all.

Initial symptoms may include fever, headache, muscle pain, vomiting and sore throat. For some people, these symptoms may cause drowsiness, altered consciousness, and pneumonia.

Encephalitis is a sometimes fatal disease that causes inflammation of the brain and can occur in severe cases.

To date, no drugs or vaccines have been approved to treat the disease.

The first recognized outbreak of Nipah virus was in 1998 among pig farmers in Malaysia and later spread to neighboring Singapore. The virus was named after the village where it was first discovered.

More than 100 people have been killed and 1 million pigs culled in an effort to contain the virus. It also causes significant economic losses to farmers and livestock traders.

Bangladesh has borne the brunt of the disease in recent years, with more than 100 people dying from Nipah virus since 2001.

The virus has also been detected in India. Outbreaks were reported in West Bengal in 2001 and 2007.

The southern state of Kerala has emerged as a Nipah hotspot in recent times. In 2018, 19 cases were reported, with 17 deaths; in 2023, two out of six confirmed cases subsequently died.

As of last week, at least five confirmed cases have been reported, all linked to a private hospital in Barasat. Local media quoted the state’s health department as saying that two nurses were being treated in the intensive care unit, one of whom was in “very critical condition.”

No cases have been reported outside India, but some countries are stepping up preventive measures.

Thailand on Sunday started screening passengers receiving flights from West Bengal at three international airports in Bangkok and Phuket. Passengers on these flights are required to make health declarations.

The Parks and Wildlife Department has also implemented stricter screening at nature tourist attractions.

Jurai Wongswasdi, a spokesman for the Department of Disease Control, told the BBC that Thai authorities are “quite confident” in preventing an outbreak in Thailand.

Nepal has also started screening people arriving through Kathmandu airport and other land border points with India.

At the same time, Taiwan’s health department proposed to list Nipah virus as a “Category 5 disease.” Under the island’s system, diseases classified as Category 5 are new or rare infections that pose a significant public health risk and require immediate reporting and special control measures.

Additional reporting by BBC Thai