Nipah Virus triggers health alerts in Asia
Kerala cases highlight localized risk
Recent Nipah virus (NiV) cases in India have once again put the disease in the public eye, despite outbreaks remaining largely localized. The latest report from the Indian government confirmed two NiV cases since December last year, with all contacts of the affected individuals quarantined and tested. Previously, between May 17 and July 12, 2025, Kerala state reported four confirmed cases, including two deaths, across Malappuram and Palakkad districts, marking the first-ever detection in Palakkad. Health officials said none of the cases appear linked to one another, suggesting independent spillover events from fruit bats, the natural reservoir of NiV.
According to the World Health Organization (WHO), NiV is a bat-borne zoonotic virus that can spread to humans through contact with infected animals such as bats or pigs, consumption of contaminated food, and, less commonly, direct human-to-human contact. Symptoms range from fever, headache, and respiratory issues to severe neurological complications, including encephalitis, seizures, and coma. Fatality rates in outbreaks across South and Southeast Asia have ranged from 40 to 100 percent, depending on healthcare access and early intervention.
Kerala has experienced nine outbreaks since 2018, with varying severity. The 2025 cases follow a pattern observed in previous years, though authorities emphasize that the overall risk to the broader national and regional population remains low. Despite the limited geographic spread, recurring spillover events underscore the ongoing risk in Kerala and highlight the potential for NiV to emerge in other Indian states where fruit bats have tested positive for the virus.
The Kerala state government implemented immediate public health measures, including emergency coordination meetings, contact tracing of 723 individuals, route mapping of confirmed cases, and special alerts for hospitals in affected districts. Authorities also advised the public to limit non-essential visits to healthcare facilities and follow strict hygiene protocols.
WHO continues to coordinate with Indian health authorities, stressing awareness of risk factors, preventive measures, and early case detection. With no licensed vaccine or treatment available, WHO recommends boiling fresh date palm sap, thoroughly washing and peeling fruit, avoiding areas where bats roost, practicing good hand hygiene, and using protective measures in healthcare and animal-handling settings.
Recent media coverage of NiV reflects concerns about its high mortality and potential to spread through bat-to-human and limited human-to-human transmission. Even though the risk of international spread is considered low, many Asian countries are keeping a close watch on the potential spread of the disease. Several countries have begun taking steps to boost prevention measures, including rigid airport entry screenings modeled after Covid-19 protocols, along with ongoing public hygiene campaigns, to minimize the risk of infection among their populations.
Thailand tightens airport screening; no reported cases
Over in Thailand, the country’s Public Health Ministry has confirmed no Nipah cases in the country but has increased screening measures for air passengers arriving from India’s West Bengal state. Dr Sophon Iamsirithavorn, deputy permanent secretary for public health, and Dr Jurai Wongsawat, director-general of the Department of Disease Control, said passengers from West Bengal will undergo body temperature checks, provide personal and travel information, and receive health warning cards after flights land at Suvarnabhumi, Don Mueang, and Phuket airports. Passengers developing symptoms are advised to call the 1422 hotline for quarantine and verification. All suspected cases tested so far have been negative.
Dr Jurai said these measures apply only to West Bengal, as Indian authorities have contained the outbreak within the state. Thai health officials also noted that while some fruit bats in Thailand carry a strong strain of the virus, the greater risk comes from infected travelers. Authorities have banned pig farms in areas where the virus has been detected in bats to prevent transmission to humans. There is currently no vaccine or treatment for NiV infection.
Screening continues for visitors from affected countries, focusing on those with fever, respiratory symptoms, or recent travel to outbreak areas. Recent outbreaks in Bangladesh and India are under control, with no evidence of the virus in nearby countries.
As per recent reports, Health officials at Suvarnabhumi Airport have not detected any symptomatic passengers. Airport director Kittipong Kittikajorn said the measures follow international standards, allowing early detection while minimizing disruption. Authorities are also reviewing travel histories for arrivals from designated surveillance areas. Enhanced screening will continue to prevent possible importation of NiV into Thailand.
Nipah virus is a highly pathogenic zoonotic RNA virus that spreads through fruit bats, infected pigs, and human-to-human contact. It can cause severe respiratory illness and fatal encephalitis, with death rates ranging from 40 to 75%. The virus was first detected in humans in Malaysia in 1998 and later in Singapore in 1999, with more than 750 cases confirmed worldwide. Outbreaks have occurred in Bangladesh, India, Malaysia, the Philippines, and Singapore, with seasonal outbreaks in Bangladesh from December to May during date palm sap harvesting, and most infections in India reported in Kerala, often linked to hospital-based transmission. Fruit bats that carry the virus are found across Asia, the South Pacific, and Australia.Symptoms typically appear four to 14 days after infection and include fever, headache, cough, sore throat, and difficulty breathing. Severe cases may lead to brain swelling, confusion, drowsiness, seizures, and coma within 24 to 48 hours. People can become infected through direct contact with infected animals, consuming food or drinks contaminated by animals, or close contact with the body fluids of an infected person. Initial animal-to-human transmission, or spillover, often occurs through contaminated fruit or raw date palm sap, and once infected, the virus can spread between humans.
— Source: CDC
Taiwan moves to upgrade NiV alert level; warns against fruit bats
Taiwan has also taken precautionary measures in response to the Kerala outbreak. The country’s Health Ministry recommended upgrading NiV to a Category 5 infectious disease, citing growing concern after the recent cases in India.
Taiwan’s Center for Disease Control and Prevention (CDC) Deputy Director General Lin Min-Cheng said fruit bats are the primary carriers, adding that harvesting date palm sap poses a particular risk if consumed raw, as bats are attracted to the sap at night and may contaminate it.
Meanwhile, officials advised avoiding travel to areas with active NiV transmission, maintaining good hygiene, washing fruit thoroughly, and using protective equipment such as gloves, masks, and clothing when handling sick animals. Travelers should exercise caution when drinking coconut juice or consuming fruit that may have been contaminated by bats.
Hospitals are urged to enforce strict infection control measures to prevent exposure to the blood, bodily fluids, or waste of infected patients. Healthcare workers and visitors should clean and disinfect their hands with soap or alcohol-based sanitizers after contact.
Cambodia urges vigilance, practical preventive measures
On its end, Cambodia has likewise increased surveillance while confirming the presence of the virus in local bat populations. The Ministry of Health said the country has not detected any human cases but emphasized vigilance, noting the virulence of the disease. To prevent infection, Cambodia’s health authorities advised frequent handwashing, avoiding contact with bats, rodents, and infected swine, and maintaining hygiene after visiting farms. Suspected animal outbreaks should prompt immediate quarantine, with infected animals culled and properly buried or cremated. Protective gloves and clothing should be used when handling sick animals, animal waste, or infected people, including during slaughter, disposal, and direct contact.
Philippines ready to monitor cases; advises well-cooked food
The Philippines has confirmed its readiness to test for NiV and monitor potential cases. According to news reports, Health Assistant Secretary Albert Domingo said the country has experience handling the virus, explaining that 17 cases were reported in Sultan Kudarat in 2014. Sultan Kudarat is a province in the SOCCSKSARGEN region in Mindanao. Domingo said that bats are the most common source of the virus, but other animals, including pigs and horses, can also become infected and transmit it. He urged the public to consume meat approved by the National Meat Inspection Service (NMIS) and to always cook food thoroughly.
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