India is monitoring Nipah virus infections, with two reported from its eastern state of West Bengal since December, the health ministry said, as some Southeast Asia nations step up scrutiny of air travellers.

Tuesday’s confirmation came a day after Thailand said it had tightened airport screening measures, with neighbouring Malaysia following suit.

“Speculative and incorrect figures regarding Nipah virus cases are being circulated,” the Indian ministry warned in a statement that put the tally of infections at two.

Authorities have identified and traced 196 contacts linked to both cases, it added, with none showing symptoms and all testing negative for the virus.

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

Malaysia’s health ministry said it was beefing up preparedness via health screening at international ports of entry, especially for arrivals from countries at risk.

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

The World Health Organisation (WHO), which estimates Nipah’s fatality rate at 40% to 75%, ranks it as a priority pathogen for its potential to trigger an epidemic.

There is no vaccine to prevent infection and no treatment to cure it.