An outbreak of the highly fatal Nipah virus in India’s eastern state of West Bengal has sparked widespread attention and public concern in China ahead of the Lunar New Year holiday when millions will travel.
While the virus has infected at least five people in West Bengal, including one in critical condition, Chinese health experts say it is difficult to transmit and less likely to cause an outbreak in China.
With a fatality rate of up to 75 per cent and no effective treatment or vaccines available, the virus has triggered unease in China, with related topics trending on the country’s social media platforms on Monday.
“It’s so scary, especially with the Spring Festival coming up. I don’t want to experience another lockdown,” one online user said, referring to the Lunar New Year holiday. Another asked, “Can’t we temporarily shut the travel channel with India?”
Last month, China and India eased visa rules for each other in a move aimed at boosting travel between the world’s two most populous countries.
The timing of the health threat to China is a concern as the Lunar New Year approaches, a period of extremely high travel traffic into, within and out of the country. The 40-day travel rush, known as chunyun, runs this year from February 2 to March 13.
In a report released last Friday, China’s Centre for Disease Control and Prevention called for “heightened vigilance” towards the risk of imported infectious diseases, including malaria, dengue fever, chikungunya fever and Lassa fever, that could be introduced by travellers returning from abroad during the festival period.
But Nipah was not listed, even though Indian media’s reporting on the outbreak can be traced to mid-January. On January 11, two healthcare workers at the All India Institute of Medical Sciences in West Bengal’s Nadia district reportedly tested positive for it.
Nipah is a deadly virus for which there are currently no specific medications or vaccines. For those who have it, the severity of symptoms can vary widely, ranging from asymptomatic infection to acute respiratory illness.
The most fatal complication of Nipah infection is inflammation of the brain, known as encephalitis. Neurological symptoms include confusion, altered consciousness, seizures and coma, and typically emerge several days to weeks following the onset of illness.
Yet health experts described the risk posed to China by the virus as manageable overall.
According to Zhao Haiyan, a Wuhan University virologist who studies highly pathogenic viruses, including Nipah, some neighbouring countries have reported sporadic outbreaks almost every year since the virus emerged in 1998, while China has not documented any imported cases.
Zhao said this did not mean the risk was zero but showed that the Nipah virus had relatively limited transmission pathways compared with highly transmissible respiratory pathogens such as influenza or Sars-CoV-2 – responsible for the coronavirus pandemic.
Nipah virus infections in humans are primarily associated with direct contact with infected animals, particularly bats or pigs, or with the consumption of food contaminated by animal secretions such as saliva, urine or faeces.
Zhao noted that human-to-human transmission could occur but was generally inefficient and typically required close contact with bodily fluids from infected patients or exposure to high viral loads, allowing the virus to enter through mucosal surfaces in the absence of appropriate infection control measures.
Overall, the likelihood of a Nipah outbreak in China was considered low under current conditions, she said. One important factor is that most bat species found in the country differ from the primary natural reservoir of the virus, Pteropus fruit bats, limiting opportunities for spillover. In addition, China does not exhibit certain high-risk exposure behaviour seen in parts of South Asia, such as the consumption of raw date palm sap.
Studies have found that, in India and Bangladesh, the major route of Nipah transmission from bats to humans is the consumption of raw date palm sap contaminated with bat saliva or urine.
Amid the threat posed by the Nipah virus and other emerging zoonotic pathogens, several research teams in China have been conducting related studies in recent years as part of broader public health preparedness efforts, with ongoing work aimed at improving surveillance, risk assessment and early warning capacity.
A Tsinghua University virologist, who declined to be named, argued that China was better equipped to contain the virus than India, citing superior public health conditions, including cleaner public facilities and different dietary habits.
However, the Tsinghua virologist said China still needed to maintain strict controls to prevent imported cases while strengthening the research and development of relevant antibody medications and vaccines.
According to Zhao, a handful of research teams in China have been working on this front since 2022 as part of a strategic public health response, with some reporting significant scientific progress.
Some countries near India are taking action to contain the spread of the virus. In Thailand, major airports have begun enhanced screening for inbound passengers, particularly those arriving from West Bengal, local media reported.
On Sunday, Thai Prime Minister Anutin Charnvirakul said, “Public health screening systems have been adjusted based on the model that we used during the Covid-19 outbreak in Thailand.”
Although there have been no Nipah cases in Thailand, the Thai leader stated that the country’s precautions should be elevated.
According to the World Health Organization, confirmed human outbreaks of Nipah have so far been limited to South Asia and Southeast Asia. Since 1998, virus outbreaks have been reported in Bangladesh, India, Malaysia, the Philippines and Singapore.
In India, infections have occurred multiple times since 2001. Between mid-May and mid-July last year, four confirmed cases of Nipah virus infection, including two deaths, were reported in two districts of Kerala, a tropical coastal state in India. -- SOUTH CHINA MORNING POST
