Bird flu could be the next pandemic
It’s one of the worst nightmares facing epidemiologists: that the virus could escape from poultry farms around the world and target human hosts.
Now researchers in India have developed models to estimate how long authorities would have to eliminate such a mutated virus before it would cause a new pandemic.
Europe is seeing an unprecedented spread of the highly pathogenic bird flu virus, prompting the cull of hundreds of millions of farmed birds, disrupting both food supplies and prices.
Although human infections are rare, researchers have raised concerns that potential mutations in the bird flu virus could make it a top candidate for causing a future pandemic.
Researchers at Ashoka University have developed a computer simulation to assess how an H5N1 outbreak might emerge, spread and be controlled in a population after the virus jumped from birds to humans.
Researchers used a computer model called BharatSim, which simulates how people interact in households, workplaces and markets, to map out how a virus might spread in real life.
They modeled the interactions of nearly 10,000 people in the Namakkal district of southern India, a major poultry hub with more than 1,600 poultry farms and a likely location where the virus could spread to humans.
In the simulation, the virus first jumps from birds to people working on a medium-sized farm or wet market.
These primary contacts infect their relatives, who form secondary contacts and spread it to tertiary contacts through broader interactions.
Researchers also simulated various interventions to prevent the spread of the virus, such as culling birds, quarantining infected people and a targeted vaccination campaign.
Culling could reduce transmission of the virus, but only if it happens within 10 days of detection of the outbreak, before peak infection spreads through the bird population.
“The sooner birds are culled, the greater the chance that a spillover can be prevented,” they said.
The simulation showed that quarantine was the most effective step to stop human-to-human spread, but this had to be done when the number of infected people was only two.
Assuming people move from home to workplace or school every 12 hours, researchers predict the virus could spread to tertiary contacts after just two days.
“It is in the very early stages of an outbreak that control measures make the most difference,” researchers noted. “Once community transmission takes over, broader public health measures such as lockdowns, mandatory masking and mass vaccination campaigns are the only options left.”
