NEW research has modelled the speed at which avian influenza can spread in Asia’s live bird markets. 

The findings will help researchers evaluate the impact of potential control measures to reduce H9N2 (a subtype of avian influenza) in markets.

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H9N2 is a zoonotic virus defined as low pathogenic and causes mild diseases that can lead to production losses for poultry farmers. 

Genes from H9N2 have, however, also been found in the emergence of new influenza virus variants, making it a potential pandemic threat, with its first human infection reported in Vietnam in April 2024.

Published in Nature Communications, the study found that: 

  • More than nine in 10 chickens that enter live bird markets without having been previously exposed to the H9N2 subtype of avian influenza virus become infected, should they remain there for one day.
  • The time between a bird being infected with H9N2 and it becoming contagious can be less than five and a half hours in a live bird market.
  • One in 10 birds arrive at live bird markets already exposed to H9N2.

Dr Guillaume Fournié, Researcher at the RVC and INRAE, said: “Our research suggests that unless any practical measures designed to protect market traders and shoppers are complemented by interventions in the networks and supply chains that deliver the birds to market – they are unlikely to have enough impact. 

“To be successful a pandemic prevention strategy must also target chicken farmers and transporters in countries where the virus is endemic in order to reduce viral burden in markets.

“Our findings make a clear case for considering multipronged interventions, including vaccination strategies for all poultry destined for sale in live bird markets.”

The full paper can be accessed at: https://www.nature.com/articles/s41467-024-47703-9