The paper, from senior scientists in the GCRF One Health Poultry Hub, describes how a computer model of avian influenza virus transmission was for the first time input with biological data obtained from chickens in live bird markets (also known as wet markets). Previous attempts to model avian influenza spread have only ever been theoretical.
The findings, published in Nature Communications, show 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 with it 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.
The H9N2 sub-type of avian influenza virus is zoonotic, i.e., it can spread to people. It is defined as low pathogenic and causes mild disease but can lead to substantial production losses for chicken farmers.
The H9N2 virus has been involved as a gene donor in the emergence of new influenza virus variants. Hence it is considered a potential pandemic threat. Earlier this month, Vietnam reported its first human infection with H9N2.