Food and drink holiday warning issued after deadly virus outbreak | World | News

News of an outbreak of a deadly disease with “pandemic potential” will no doubt trigger flashbacks to the dark days of Covid when we were told to stay home and sing Happy Birthday twice while washing our hands. This time, it’s the bat-borne Nipah virus, a zoonotic infection with a death rate of between 40% and 75%, according to the UK Health Security Agency (UKHSA), that’s posing a problem.

Officials in India have been racing to contain the virus after two healthcare workers at a hospital in the eastern state of West Bengal fell ill in late December. One case remained on mechanical ventilation as of January 21, while the other experienced severe neurological illness but has improved. Around 200 people who came into contact with the victims have been traced and tested, hospitals have stepped up infection protocols, and some nearby countries have tightened border controls and implemented health screening at major airports.

The World Health Organisation has described Nipah as one of its top 10 priority diseases because of its potential to spark an epidemic or pandemic. The UKHSA also designated it as a high priority pathogen last March, meaning that new tests, treatments and vaccines are urgently needed. So, how worried should we be? We asked two experts in medicine and virology to tell us everything we need to know about Nipah.

What is Nipah virus?

Nipah virus is a zoonotic disease that can be transmitted from animals, including bats and pigs, to humans. Fruit bats of the Pteropodidae family are the natural host and carry the virus without falling ill, then spread it through saliva, urine and faeces.

The pathogen was first discovered in 1999, a few months after a mysterious and deadly outbreak among pig farmers in Malaysia. Health officials originally thought those falling ill with brain inflammation were suffering from Japanese Encephalitis, a mosquito-borne disease. But when the deaths continued, scientists isolated the new virus.

Nipah can be transferred through contact with infected animals or their environments, via food, or through close contact with an infected person. The consumption of contaminated raw date palm syrup has also been implicated.

Subsequent outbreaks have been seen in Bangladesh, India, Malaysia, the Philippines and Singapore. Professor Paul Hunter, an expert in medicine at the University of East Anglia, said: “Typically we get one or two Nipah virus outbreaks each year. There was a significant one in 2023, in West Bengal as well.”

Dr Efstathios Giotis, a lecturer in molecular virology at the University of Essex, said the current cases “seem to be contained”. “There is no evidence that there’s wider community spread and I haven’t read anything particularly worrying. There have been outbreaks of Nipah virus in the region in the past.”

What are the symptoms?

Dr Giotis described Nipah as a “serious disease”. “It can cause flu-like symptoms or it can invade the central nervous system and cause encephalitis, inflammation of the brain — that’s the most serious symptom,” the expert said. “That’s usually the main cause of death and it can cause long-term disability.”

Early symptoms typically include fever, headaches, muscle pain and vomiting, sometimes followed by dizziness and drowsiness. This can can progress to pneumonia and severe respiratory problems, seizures and coma.

Encephalitis occurs when the virus breaches the blood-brain barrier, leading to swelling and potentially causing lasting brain damage and neurological problems. This ability is what makes Nipah so lethal and why it is classified as a “neurotropic” virus, meaning one that targets the nervous system.

There are no specific treatments, so patients are given supportive care in hospital while their bodies fight the infection. People can also be infected without showing any symptoms, and the virus can sometimes reactivate months or even years after the initial infection.

Why is there no vaccine or treatment for Nipah?

The virus poses a challenge to researchers — it is very deadly, so treatments and vaccines are desperately needed. However, cases are relatively rare.

Prof Hunter explained: “The problem is that, because there are so few cases each year, proving a vaccine works in the real world takes a long time. I suspect that’s why [we don’t have a vaccine yet].

“With viral infections, sometimes antiviral drugs work, sometimes they don’t. Again, the problem is that, to know whether a treatment has benefit, you need to have enough cases.

“When you have a disease like Nipah virus, where outbreaks are generally small and in rural areas, the commercial pressure to develop something quickly isn’t as great. You might spend tens of millions bringing a drug to treatment, and then you can only use it three or four times a year in a low income country.”

Dr Giotis added: “Scientists are interested in it but because the outbreaks are rare and sporadic, that makes clinical trials a bit more difficult.”

How deadly is Nipah?

The death rate can vary between outbreaks, partly depending on local capabilities for identifying and containing cases. The UKHSA estimates that it falls between 40% and 75%, while Prof Hunter estimated that it ranges from 50% to 90%. “With a mortality rate like that, it is a substantially scary disease,” he added.

“You’ve probably got a 50% chance or more of dying, I think that’s pretty serious. It is a very nasty disease. Fortunately it’s not that infectious person-to-person at the moment.”

During the first outbreak among pig farmers, the virus appeared to only spread from animals to people. However, it was found to also spread from human to human during later outbreaks.

Could Nipah virus cause a pandemic?

Nipah inspired the 2011 Hollywood thriller, Contagion, which featured a virus called MEV-1 that triggers a global crisis. The fictional pathogen was transmitted from bats to pigs, and then to Gwyneth Paltrow via a handshake with a chef who did not wash his hands properly after handling raw meat.

There has never been a case of Nipah recorded in the UK and the potential for the current strain to cause a wider outbreak is considered low. But if it mutates to become more easily transmissible, it could quickly spread around the world.

Prof Hunter said: “Its pandemic potential is very low. It’s unlikely that it would cause more widespread outbreaks. Of course, viruses do have the potential to evolve, so I can’t guarantee that Nipah, at some point in the future, evolve to be more infectious.

“That hasn’t happened so far and, fingers crossed, it won’t in my lifetime. But we can’t just ignore it and say, ‘It’s not going to spread so we’ll just forget about it’.” This is why Nipah has been described by the World Health Organisation and UKHSA as a priority pathogen.

Dr Giotis said the virus does not spread as easily as other viruses such as flu, and doesn’t have the same ability to spread near-silently that made Covid so dangerous.

He added: “We need to see the genetic sequencing of this new strain, but so far we haven’t seen any evidence that the virus has changed in a way that makes it more transmissible or more lethal. The risk is quite low from what we’ve seen so far.”

Is it safe to go on holiday?

One of the major concerns around the India outbreak is that it coincides with a busy travel period, when people traverse Asia to celebrate the Lunar New Year.

Some airports in Thailand have started screening passengers arriving in Bangkok and Phuket from West Bengal, and the country’s parks and wildlife department has implemented stricter screenings at tourist attractions.

So what should you do if you have a holiday booked to an affected country? Prof Hunter said “most of the recent outbreaks have been in Bangladesh, West Bengal, Kerala”. He added: “There have been some elsewhere. The best advice is just be careful what you eat.

“There is a drink, palm tree sap, and sometimes it is fermented into an alcoholic beverage. That has been implicated several times so don’t drink juice that has not been pasteurised or heated, and make sure you peel fruit properly before you eat it — which is good advice for lots of things other than Nipah virus.

“Outbreaks occur most years but they generally are quite small. The risk is actually very low, particularly if you’re going to touristy areas.”

Dr Giotis similarly advised “some caution” but said the risk of infection for travellers is generally low. “Avoid contact with animals — bats, pigs — or sick individuals. Practice normal hygiene, hand washing, safe foods, avoid raw fruit juice. And of course seek medical care if you develop a fever after travelling.

“There’s no need to panic. Based on what we have heard so far, there’s no evidence of community spread so I don’t think travellers should panic. The whole situation seems to be low risk, just use common sense.”