Beyond Nipah Virus: New Bat Virus Found In Bangladesh Patients, Warn Scientists

A recent scientific study has revealed that a bat-borne virus unrelated to Nipah has been infecting humans in Bangladesh, raising new questions about zoonotic disease surveillance in South Asia. While Nipah virus, a deadly pathogen spread by fruit bats, is already a known public health threat in parts of India and Bangladesh, researchers found evidence of another virus called Pteropine orthoreovirus (PRV) in patients who displayed severe symptoms similar to Nipah but tested negative for it.

Published in the journal Emerging Infectious Diseases, the research highlights that PRV, previously overlooked because it mimics Nipah-like symptoms, was detected in archived throat swab samples from five patients who had recently consumed raw date-palm sap, a known transmission route for bat viruses in the region.

Scientists say this discovery suggests that dangerous bat viruses may be circulating among humans more often than recognized, especially in areas where human-bat interfaces are common. The findings have implications for India and other nations where these viruses are endemic and illustrate the need for broader surveillance and testing beyond just Nipah virus.

Hidden Virus Found: What the Study Says

Researchers from the Mailman School of Public Health at Columbia University and Bangladeshi partners analysed stored clinical samples from five patients in Bangladesh who were originally suspected of having Nipah virus infection due to symptoms like fever, headache, vomiting, fatigue and neurological involvement. However, standard tests for Nipah came back negative.

Using advanced genomic techniques, viral capture sequencing (VCS), scientists identified genetic material of Pteropine orthoreovirus (PRV) in these samples and were able to grow the live virus in culture, confirming active infection.

PRV belongs to a family of viruses known to be carried by bats and previously documented mostly in animals or associated with mild human illness in other parts of the world. The new finding in Bangladesh indicates that the virus can cause serious symptoms in humans, including respiratory and brain-related illness, and may evade detection if only standard Nipah tests are used.

Also Read: Why Nipah Virus Isn't The Next Covid-19: 3 Diseases Might Be Bigger Pandemic Risks

Why This Matters in Regions Endemic for Nipah

This discovery comes at a time when Nipah virus remains a major concern in Bangladesh and neighbouring regions of India, including West Bengal and Kerala, where periodic outbreaks have been recorded. According to the World Health Organization (WHO), Nipah virus infections have a high fatality rate (40-75%) and can be transmitted via bats, contaminated food, or direct person-to-person contact. 

The risk of Nipah outbreaks is particularly heightened during winter and early spring when fruit bats feed on raw date-palm sap, a staple seasonal treat, and can contaminate it with saliva or urine. This has already been documented as a major spillover route for Nipah.

Now the PRV finding expands that picture. "Our results show that the risk of disease associated with raw date-palm sap consumption goes beyond Nipah virus," said Dr. Nischay Mishra, lead author of the study. Researchers emphasise that PRV infections should be considered when doctors assess patients with Nipah-like symptoms.

Implications for India and Other Nations

Countries neighbouring Bangladesh, such as India, Nepal, Myanmar and Bhutan, also have environments where zoonotic spillover from bats can occur. Recent Nipah cases in West Bengal, India have triggered increased surveillance and public health responses. While the WHO currently assesses the risk of widespread Nipah transmission as low to moderate, given limited human-to-human spread, the discovery of PRV highlights that surveillance focusing only on one virus may miss other threats.

Experts are now calling for broader infectious disease surveillance programs in regions where people and bats live in close proximity. This could include genetic sequencing tools capable of detecting a wide range of viruses, not just targeted tests for known pathogens.

Also Read: How Kerala Learned To Contain Nipah Virus Outbreaks Without A Vaccine: Lessons In Public Health

What People Should Know and Do

• Avoid raw date-palm sap unless it has been properly processed or boiled, especially in areas where bats are present.
• Seek medical attention for symptoms like fever, severe headache, vomiting, disorientation or breathing problems if you have exposure to bats or bat-contaminated food.
• Support local public health efforts in expanding surveillance to include broad-spectrum viral testing, particularly in endemic regions.

The detection of a previously unnoticed bat virus (PRV) in Bangladeshi patients with Nipah-like symptoms points to wider viral threats lurking in human-animal interfaces. For India and neighbouring countries where bat-borne diseases are endemic, this study underscores the importance of comprehensive surveillance, diagnostic tools, and public awareness. While Nipah virus remains a serious health concern, the new findings suggest that other viruses may be silently impacting human health, and that preparedness must evolve beyond single-pathogen approaches.

Disclaimer: This content including advice provides generic information only. It is in no way a substitute for a qualified medical opinion. Always consult a specialist or your own doctor for more information. NDTV does not claim responsibility for this information.