New Insights from Indian Scientists on Potential Bird Flu Infections in Humans

Thu Dec 18 2025 18:58:39 GMT+0200 (Eastern European Standard Time)

A recent study by Indian researchers sheds light on how the avian flu, particularly the H5N1 strain, may spread to humans and suggests strategies for prevention and containment.

Indian scientists have developed a model that predicts how H5N1 bird flu could potentially infect humans and emphasizes the importance of timely intervention. The study suggests that early action can contain outbreaks effectively and highlights the need for robust surveillance systems as the virus continues to affect the poultry industry worldwide.

For years, scientists have warned that bird flu - better known as H5N1 - could one day make the dangerous leap from birds to humans and trigger a global health crisis.

Avian flu - a type of influenza - is entrenched across South and South-East Asia and has occasionally infected humans since emerging in China in the late 1990s. From 2003 to August 2025, the World Health Organization (WHO) has reported 990 human H5N1 cases across 25 countries, including 475 deaths - a 48% fatality rate.

In the US alone, the virus has struck more than 180 million birds, spread to over 1,000 dairy herds in 18 states, and infected at least 70 people - mostly farmworkers - causing several hospitalisations and one death. In January, three tigers and a leopard died at a wildlife rescue centre in India's Nagpur city from the virus that typically infects birds.

Symptoms in humans mimic a severe flu: high fever, cough, sore throat, muscle aches and, at times, conjunctivitis. Some people have no symptoms at all. The risk to humans remains low, but authorities are watching H5N1 closely for any shift that could make it spread more easily.

That concern is what prompted new peer-reviewed modelling by Indian researchers Philip Cherian and Gautam Menon of Ashoka University, which simulates how an H5N1 outbreak might unfold in humans and what early interventions could stop it before it spreads.

The model uses real world data and computer simulations to play out how an outbreak could spread. Prof Menon said, 'The threat of an H5N1 pandemic in humans is a genuine one, but we can hope to forestall it through better surveillance and a more nimble public-health response.'

A bird flu pandemic, researchers say, would begin with a single infected bird passing the virus to a human - most likely a farmer or market worker. From there, the danger lies not in that first infection but in what happens next: sustained human-to-human transmission.

Because outbreaks often start with limited data, the researchers used BharatSim, a simulation platform originally designed for analysing Covid 19, to explore H5N1's potential spread.

The models estimate that once cases rise beyond roughly two to ten, the disease is likely to spread beyond primary and secondary contacts. Effective intervention measures were highlighted, showing that quarantining primary contacts when just two cases are detected can contain outbreaks.

The simulations indicate that culling infected birds works well, but timing is critical. If humans become infected, isolating them and their households can prevent further spread, but once tertiary infections emerge, containing an outbreak is challenging without stricter measures like lockdowns.

Ultimately, the study emphasizes the crucial need for effective, timely public health responses when faced with H5N1, especially given India's significant poultry industry, which poses risks if outbreaks are not carefully monitored and managed.