What is Nipah virus? The highly lethal disease causing concern across Asia

Airports across Asia have put urgent steps in place to stop the spread of a highly lethal virus.

Temperature screening has been set up by authorities in Singapore, Thailand and Malaysia after two cases of Nipah virus were detected in India in late December.

The Indian health ministry said in a statement on 27 January that the cases in the eastern state of West Bengal have been contained but precautions in neighbouring countries as well as Nepal and Hong Kong remain in place.

While there has never been a case reported in the UK, the country's Health and Security Agency (UKHSA) has released information about the disease to educate Britons planning to travel to areas where it circulates.

Here's what you need to know about Nipah virus, from how it spreads, possible symptoms and whether it can be treated.

What is Nipah virus?

Nipah virus infection is a zoonotic illness (meaning it can be spread between animals and humans) that can cause a range of illnesses, the World Health Organization (WHO) says.

The virus can also spread quickly from person to person through close contact, as well as through contaminated food.

It is typically carried by fruit bats, particularly a breed of megabat known as the large flying fox, but other animals, including pigs, can also carry the virus.

What are the symptoms?

Symptoms in humans can range from an asymptomatic infection - when you show little to no symptoms - to deadly brain-swelling known as encephalitis.

Infected people are likely to develop symptoms that include:

• Fever
• Headaches
• Muscle pain
• Vomiting
• Sore throat

These symptoms can be followed by dizziness, drowsiness, altered consciousness, and neurological signs that indicate acute encephalitis, according to WHO.

Most people make a full recovery from the virus, but some cases of relapse have been reported.

The fatality rate is an estimated 40-75%, WHO reports, but this can vary depending on the outbreak.

Health authorities in India identified and traced 196 contacts linked to the two latest cases, with all of them testing negative for the virus and none of them displaying symptoms.

Can it be treated?

There is currently no proven treatment for the virus. Several vaccines against it are in development, but remain in the testing phase.

Treatment often involves intensive care in a hospital to help with severe respiratory or neurological conditions.

Are outbreaks common?

The first recognised outbreak was among pig farmers in Malaysia in 1999. Singapore was also affected.

India is considered among the world's most at risk regions for Nipah ​outbreaks, while human infections have been reported almost every year in Bangladesh since it first appeared in 2001, according to WHO.

The current cases are the first in West Bengal in nearly two decades, local media reported. In 2007 five people died from the virus.

How are countries responding to the outbreak?

Singapore's Communicable Diseases Agency said on 28 January that passengers on flights arriving from affected areas in India will be subject to temperature screening at its airport.

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

Authorities in Thailand also said passengers arriving from areas with Nipah infections must complete health declarations before clearing immigration.

China's disease control authority said that while no cases have been detected in the country, there were risks of imported cases. While Nepal said it was on "high alert" and had also implemented tightened screening for travellers.

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How to prepare if you are travelling to at-risk countries

The UKHSA says Britons travelling to areas at risk of the virus should focus on avoiding contact with bats and sick animals, as well as ensuring to wash all fruit thoroughly with clean water and peel it before eating.

Other advice to help limit potential exposure to the virus includes:

• Wearing protective clothing when handling sick animals
• Practice good hygiene techniques, particularly after caring for or visiting sick people
• Avoid close contact to anyone infected with Nipah virus

(c) Sky News 2026: What is Nipah virus? The highly lethal disease causing concern across Asia