Authorities across Singapore, Hong Kong, Thailand and Malaysia have taken urgent steps to stop the highly lethal and epidemic‑prone Nipah virus spreading beyond India, rolling out airport temperature checks and other screening measures.

Nipah is classified as a priority pathogen by the World Health Organization because of its ability to spark fast‑moving outbreaks, its fatality rate of 40% to 75%, and the fact that there is no approved vaccine or cure.

Two infections were confirmed in India in late December.

The virus, carried by fruit bats and animals such as pigs, can trigger a deadly brain-swelling fever in humans and can also spread directly from person to person through close contact. Several vaccines are in development but remain in testing.

Indian health workers infected

The two people infected in the eastern Indian state of West Bengal in late December were health workers and both are under treatment at a local hospital, a district health officer told Reuters.

Authorities have identified and traced 196 contacts linked to the two cases with none showing symptoms and all testing negative for the virus, the Indian health ministry said in a statement late on Tuesday.

"Speculative and incorrect figures regarding Nipah virus disease cases are being circulated," the statement said. "Enhanced surveillance, laboratory testing, and field investigations were undertaken ... which ensured timely containment of the cases."

Reports of the infections put authorities on alert in neighbouring Southeast Asian nations as well as Nepal and Hong Kong.

Temperature screening at Singapore airport

Singapore's Communicable Diseases Agency said on Wednesday that it will set up temperature screening at its airport for flights arriving from areas affected by the infections in India.

The Ministry of Manpower is stepping up surveillance over newly arrived migrant workers from South Asia, and engaging primary care providers to increase vigilance, it said.

"We are also reaching out to our counterparts in South Asia, to better understand the situation. Work is ongoing to establish a global platform for countries to report genome sequencing of detected cases," the agency said in a statement.

A Hong Kong airport authority spokesperson said it was facilitating enhanced health screening measures enforced by the health department at Hong Kong International Airport, including temperature check at gates for passengers arriving from India.

Designated aircraft parking in Thailand

Thailand earlier this week tightened airport screening measures, with neighbouring Malaysia following suit.

Thailand has assigned designated parking bays for aircraft arriving from areas with Nipah infections, its health ministry said, while passengers must complete health declarations before clearing immigration.

Malaysia's health ministry said it was boosting preparedness through health screening at international ports of entry, particularly for arrivals from countries deemed at risk.

"The ministry remains vigilant against the risk of cross-border transmission following sporadic infections in several other countries," it said in a statement on Wednesday.

China's disease control authority said on Tuesday that no Nipah infections had been detected in the country but there were risks of imported cases, state broadcaster CCTV said on Tuesday.

Nepal, which shares a busy border with India, said it was on "high alert" and had tightened screening for travellers. Health ministry officials said border points with India and China had been notified to remain vigilant and check suspected cases.

Nipah not news to India

Nipah was first identified in 1998 during an outbreak among pig farmers in Malaysia and Singapore, although scientists believe it has circulated in flying foxes for millennia and warn that a mutated, highly transmissible strain could emerge from bats.

India regularly reports sporadic infections, particularly in the southern state of Kerala, considered among the world's most at-risk regions for Nipah outbreaks. The virus has been linked to the deaths of dozens of people in Kerala since it first appeared there in 2018.

The West Bengal cases are the state's first in nearly two decades, following five fatal infections in 2007, local media reported.