A fresh bird flu outbreak in Maharashtra’s Navapur has triggered alarm among scientists and health experts, not merely because of the immediate economic loss-with over one lakh chickens set to be culled-but due to a deeper, more unsettling concern: the virus may be inching closer to becoming a serious threat to humans.
The outbreak comes just months after thousands of crows were found dead in the state due to highly pathogenic avian influenza, commonly known as the Influenza A H5N1 virus – notorious for causing severe disease and mass mortality in birds, underscoring a troubling pattern of recurrence.
While bird flu outbreaks are not new, experts say the evolving nature of the virus and its increasing interaction with mammals could signal a shift with potentially grave consequences.
“Bird flu outbreaks are very common in nature,” veteran virologist Dr Shahid Jameel, told India Today.
“Migratory birds are reservoirs that carry the virus around the world and pass it on to backyard poultry and poultry farms.”
But what has scientists on edge is not the recurrence itself – it is what the virus is becoming.
RISING MUTATION RISK
Dr Jameel, a research fellow at Oxford University’s Green Templeton College, explained that while transmission to humans does occur, it remains inefficient due to biological barriers.
“The bird flu virus can transmit to humans but inefficiently because of the structures on the virus surface and receptors on the upper respiratory tract lining,” he said. Yet, once infection does occur, the consequences can be severe.
“Chances of severe disease and mortality are high.”
The larger fear, however, lies in the virus’s ongoing evolution.
“The real worry is that bird flu viruses have been mutating and adapting better to transmission in mammals,” DrJameel warned. Traditionally, pigs were considered the primary “mixing vessels” for flu viruses because they can host both avian and human strains.
Now, that landscape is changing.
“More recently, bird flu viruses have been found in cattle-cows in the USA and elsewhere,” he noted. “Such adapted viruses are a big risk for humans, but we don’t know whether an outbreak of these would behave like bird flu with high mortality or human flu with low mortality. I find this to be the real risk for humans.”
This uncertainty – whether a future strain could combine high transmissibility with high mortality – is precisely what makes the current situation so concerning for global health experts.
SURVEILLANCE AND SPREAD
For Dr Anurag Agarwal, a leading biologist, the apparent rise in outbreaks may partly reflect improved detection systems rather than an absolute surge in cases.
“The better the surveillance, the more we find these things,” Dr Agarwal, who is dean, biosciences and health research with Asoka University, said, pointing to regions like Kerala where frequent reporting has been observed.
“With increasing close contact between animals and humans, the rise of flu variants that can jump between the two is expected.”
He added that post-pandemic vigilance has likely sharpened monitoring systems. “It is better after COVID-19. To me, it seems that detection has increased post-pandemic due to surveillance, but impossible to say for sure.”
Early detection and rapid response remain the most critical tools in preventing escalation, experts stress.
As human-animal interfaces grow – through farming, urbanisation, and environmental changes – the opportunities for viruses to cross species barriers are also expanding.
In contrast, some experts urge a measured perspective. Dr Ishwar Gilada, a Mumbai-based infectious disease specialist, noted that human infections remain exceedingly rare.
“Very rarely, it goes from animal to human being,” he said, pointing out that globally, fewer than 1,000 cases have been recorded.
In India, only a handful of cases have ever been documented and in the last couple of years, no case, he added, referring to the absence of recent confirmed human infections within the country.
Dr Gilada emphasised that those most at risk are individuals with direct exposure to infected animals, such as poultry workers or those handling livestock. “As long as it is not coming to human beings, it is not a major concern,” he said.
Crucially, he highlighted that sustained human-to-human transmission of H5N1 – the most concerning bird flu strain – has not been confirmed.
Yet, even this cautious view does not fully dispel the unease among scientists.
The Navapur outbreak, like others before it, has already led to drastic containment measures, including mass culling and heightened surveillance.
Poultry farmers, facing heavy financial losses, are seeking compensation as authorities scramble to contain the spread.
But beyond the immediate crisis lies a more complex and potentially dangerous reality. The virus is no longer confined to birds alone, and each new host species it infects increases the chances of genetic changes that could alter its behaviour.
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