A recently emerged strain of avian influenza virus in poultry in Southeast Asia known as A(H5N6) represents a new threat to animal health and livelihoods and must be closely monitored, the U.N. Food & Agriculture Organization (FAO) said Sept. 22.
Authorities in China first reported the influenza A(H5N6) virus in poultry in April 2014. Since then, Laos and Vietnam have also detected the H5N6 virus in poultry.
"Influenza viruses are constantly mixing and recombining to form new threats," FAO chief veterinary officer Juan Lubroth said. "However, H5N6 is particularly worrisome, since it has been detected in several places so far from one another, and because it is so highly pathogenic, meaning infected poultry quickly become sick and, within 72 hours, death rates are very high."
The fact that the virus is highly virulent in chickens and geese and potentially spread across a large part of Southeast Asia translates into a real threat to poultry-related livelihoods. Poultry contributes to the incomes of hundreds of millions of people throughout the region, FAO said.
The World Organization for Animal Health (OIE), which works together with FAO and the World Health Organization (WHO) to support countries' responses to animal and human disease threats, is also monitoring the situation closely.
"An effective surveillance and an early detection of animal disease at source are two main keys to reduce the risk of dissemination and to ensure safe trade. OIE calls on its 180 member countries to respect their commitment and to immediately notify on WAHIS any outbreak detected on their territory," OIE director-general Bernard Vallat said.
Limited threat to human health
Only one case of H5N6 has been reported in humans after contact with exposure to poultry shortly after its detection in China, FAO said. The person later died. There have been no other human cases.
Although the scientific community is still in the process of understanding the dynamics of this new strain, it is unlikely that H5N6 represents an immediate and significant threat to human health, FAO reported.
"Current evidence suggests H5N6 poses a limited threat to human health at this stage," WHO epidemiologist Elizabeth Mumford added. "It's been detected in multiple places in poultry, yet we only have one human infection reported. This suggests that the virus does not easily jump from animals to humans. Of course, we still need to remain vigilant, because prevalence in poultry and therefore human exposure could increase during the winter."
Even if the public health risks posed by H5N6 currently appears to be low, other pathogens, including other subtypes of influenza viruses such as H5N1 and H7N9, still can present cause for concern.
FAO and WHO are stressing that at this time it is critical for countries in Southeast and East Asia — especially those with links to poultry production and trade — to ramp up efforts to detect and report influenza viruses in poultry and monitor for any human infections.