Officials across the globe, including the US, are on alert after a deadly bat-borne virus was detected in humans.
India has so far confirmed two cases of Nipah virus, a rare bat-borne disease, in two nurses that work at a hospital around 15 miles outside Kolkata, West Bengal, India’s third-largest metropolitan area and home to 16 million people. One is set to be discharged soon and one is in a coma.
Local media has reported that three additional patients, a doctor, nurse and another staff member also had symptoms, but Indian officials have said there is no outbreak and they are not concerned about further spread.
The country’s health ministry revealed Wednesday that 196 people who came into contact with infected patients are now being monitored for the virus, which can spread from person-to-person and kills 40 to 75 percent of those it infects.
This is 86 more individuals than the prior day, though officials said none were showing symptoms and all had tested negative for the virus thus far.
Following reports of the outbreak, Pakistan, Thailand, Singapore, Nepal, Hong Kong, Malaysia, Indonesia, Vietnam and the Philippines have all implemented enhanced screening procedures at airports, and the UK has warned travelers about the potential outbreak.
Nipah virus has never been detected in the US, but experts fear it could reach America if someone who is infected travels to America and told Daily Mail the virus poses a ‘real’ risk.
Dr Krutika Kuppalli, an infectious diseases expert in Texas who previously worked at the World Health Organization (WHO), told the Daily Mail that a Nipah virus outbreak was ‘absolutely’ something that the CDC should be ‘closely monitoring,’ though the current risk was low.
Some parts of Asia have tightened screening measures at airports to control the spread. Around 200 people who came into contact with the infected patients have been quarantined as a precaution
An ambulance is parked outside of the medical clinic at Suvarnabhumi Airport in Bangkok, Thailand this month as the country tightened health screening after cases of Nipah virus were confirmed in India
She said: ‘Nipah virus is a high-consequence pathogen, and even small, apparently contained outbreaks warrant careful surveillance, information sharing, and preparedness.
‘Outbreaks like this also underscore the importance of strong relationships with global partners, particularly the WHO, [which] plays a central role in coordinating outbreak response and sharing timely, on-the-ground information.’
CDC officials told the Daily Mail they were in ‘close contact’ with authorities on the ground in India to assess the situation.
A spokesman said: ‘CDC is monitoring the situation and stands ready to assist as needed.’
So far, no cases have been reported outside India, and there is no sign of Nipah spreading to the US or elsewhere in North America. But the response shows just how seriously authorities are treating the risk.
Nipah has a fatality rate of between 40 and 75 per cent, according to the World Health Organization, from complications such as respiratory failure and swelling of the brain.
Nipah remains rare, but experts warn it has the potential to cause devastating illness when it strikes.
Here’s what it is, how it spreads – and how worried we should be about the outbreak escalating.
What is Nipah virus?
Nipah is a zoonotic infection, meaning it can pass from animals to humans. It is most notably linked to fruit bats, and in some outbreaks, pigs.
It’s a virus that worries health officials because it can hit fast and hard, causing anything from no symptoms at all to a sudden, severe illness that attacks the lungs and the brain.
In milder cases, people may only feel flu-like symptoms, but in severe cases it can trigger acute respiratory distress, seizures and encephalitis, a dangerous swelling of the brain that can be fatal.
Another reason it sets alarm bells ringing is that it has been shown to spread person-to-person, particularly among family members and caregivers, making strict infection control crucial when cases are detected.
Health authorities monitor Nipah virus due to its outbreak potential and because its death rate in confirmed cases is unusually high.
Where are authorities screening for it?
The infection is caused by the Nipah virus, a rare but highly dangerous pathogen that can trigger severe breathing problems, seizures and fatal swelling of the brain. Pictured, the aftermath of a 2023 outbreak in India
Airport checks have been stepped up after cases were detected in West Bengal.
In implementing screening measures, Pakistan’s Border Health Services department said in a statement: ‘It has become imperative to strengthen preventative and surveillance measures at Pakistan’s borders.
‘All travelers shall undergo thermal screening and clinical assessment at the Point of Entry,’ which includes seaports, land borders and airports.
Travelers entering the country must provide travel history for the previous 21 days to check if they have been through ‘Nipah-affected or high-risk regions.’
In Singapore, the country’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.
Vietnamese officials ordered the screening of incoming passengers at some international border crossings, particularly those arriving from India, and they will be checked with body temperature scanners.
In Hong Kong, an airport authority spokesman said it was facilitating enhanced health screening measures, including a temperature check at gates for passengers arriving from India.
Earlier this week, Thailand tightened its airport screenings, requiring passengers arriving from India to complete health declarations.
Malaysia’s public health ministry also said it was boosting health screenings at airports, particularly for arrivals from countries deemed ‘at risk’.
In China, authorities said Tuesday that no Nipah virus cases had been detected in the country but that there was a risk of imported cases.
Nepal, which shares a 1,000-kilometer border with India, said it was on ‘high alert’ and had tightened screening of travelers.
Fruit bats – depicted by the areas in yellow – are even found where Nipah outbreaks haven’t occurred
Health ministry officials said border points with India and China had been notified to remain vigilant and check suspected cases.
The Philippines has also tightened checks at airports and implemented passenger screenings, with the outbreak linked to healthcare settings where viruses can spread quickly if not contained.
Thailand has started screening arrivals at international airports receiving flights from the region, while Nepal has introduced checks at Kathmandu airport and at land border points with India.
While measures like these can look dramatic, officials are trying to spot illness early and block any chance of infections slipping across borders.
Airport staff are said to be looking for obvious signs of illness, such as a high temperature, are flagging up passengers who have recently travelled from an affected area and reporting symptoms that could fit an early Nipah infection.
Anyone who appears unwell can then be pulled aside for further medical assessment, with health authorities able to trace contacts more quickly if an infection is suspected.
How does Nipah virus spread?
Nipah can spread from animals to humans, and it can also be transmitted through contaminated food or direct person-to-person contact.
During the first recognized outbreak in Malaysia in the late 1990s, which also affected Singapore, most human infections were linked to contact with sick pigs or their contaminated tissue, with transmission thought to have occurred through unprotected exposure to secretions from infected animals.
In later outbreaks in Bangladesh and India, researchers believe a key source of infection was consumption of fruit or fruit products contaminated by fruit bats, including raw date palm juice tainted with infected urine or saliva.
Human-to-human transmission has also been reported, particularly among family members and caregivers of infected patients.
Preliminary investigations suggest the healthcare workers in India caught the deadly virus while treating a patient with severe respiratory symptoms who died before testing could be carried out, according to sources at the hospital.
‘The most likely source of infection is a patient who had been admitted to the same hospital previously. That individual is being treated as the suspected index case, and investigated,’ a health official involved surveillance efforts told The Telegraph.
Health authorities in Taiwan are now considering listing the virus as a Category 5 disease, a rare or emerging infection with major public health risks that requires immediate reporting and special control measures.
What are the symptoms?
Nipah can begin with symptoms that look like a bad flu or stomach bug, including fever, headaches, muscle aches, vomiting and a sore throat.
In some people, it escalates into something far more serious, with dizziness, drowsiness, confusion and neurological signs that point to acute encephalitis, dangerous inflammation of the brain.
Severe cases can involve seizures and rapid deterioration, sometimes progressing to coma within 24 to 48 hours.
Some patients also develop atypical pneumonia and severe breathing problems, including acute respiratory distress.
The incubation period is usually four to 14 days, but it can sometimes be much longer. In rare instances, an incubation period of up to 45 days has been reported.
How deadly is it?
Nipah virus is watched closely by health officials because it can spread from animals to humans – and in some cases between people – yet there is no approved vaccine or specific drug treatment. Pictured, the aftermath of a 2023 outbreak in India
Nipah is known for its high fatality rate. The estimated case fatality rate is 40 to 75 percent, though this varies between outbreaks depending on how quickly patients are diagnosed and how strong clinical care and surveillance are in affected areas.
In the worst cases, Nipah can be a rapid and brutal illness because it can cause severe inflammation of the brain and acute respiratory failure.
Case descriptions from past outbreaks suggest some patients deteriorate from what looks like a standard viral illness, fever, aches and vomiting, into confusion, extreme drowsiness and seizures, before slipping into coma within 24 to 48 hours.
Others develop severe breathing problems, including pneumonia and acute respiratory distress, which can be fatal without intensive supportive care.
However, many people who survive make a full recovery, but the virus is feared because severe cases can worsen dramatically, and some survivors are left with long-term neurological damage.
There have also been reports of relapse in a small number of cases.
Is there a vaccine or treatment?
There are currently no approved vaccines or drugs that specifically target Nipah virus infection.
Instead, doctors rely on intensive supportive care, treating the most dangerous respiratory and neurological complications as they arise.
