13-7-2023 (GENEVA) The World Health Organization (WHO) issued a warning on Wednesday regarding the escalating bird flu outbreaks among mammals, stating that it could facilitate the virus’s transmission to humans.
Europe has been grappling with its most severe bird flu outbreak since late 2021, while North and South America have also witnessed significant outbreaks.
Consequently, millions of poultry worldwide, many carrying the H5N1 strain of the virus that first emerged in 1996, have been culled.
However, there has been a worrying surge in infections among mammals in recent times.
“While avian influenza viruses typically spread among birds, the growing number of H5N1 avian influenza cases among mammals, which are genetically closer to humans than birds, raises concerns that the virus may adapt to infect humans more readily,” warned the WHO in a statement.
The WHO also highlighted that some mammals could serve as mixing vessels for influenza viruses, potentially leading to the emergence of new, more harmful strains that pose a threat to both animals and humans.
Reports of outbreaks have emerged across 26 species, including farmed minks in Spain and sea lions in Chile. Additionally, cases of H5N1 infection in cats have been recently detected in Poland.
“Paradigm change”
The WHO, alongside the United Nations’ Food and Agriculture Organization (FAO) and the World Organisation for Animal Health (WOAH), called for international collaboration to safeguard animals and protect human health.
WOAH’s chief scientist, Gregorio Torres, emphasized the recent paradigm shift in the ecology and epidemiology of avian influenza, which has raised global concerns due to its spread to new geographical regions, unusual mass bird deaths, and a significant rise in mammalian cases.
In humans, infections from bird flu can lead to severe diseases with high mortality rates.
Human cases of bird flu typically occur through direct or indirect exposure to infected live or dead poultry, as well as contaminated environments.
“The virus does not appear to easily transmit from person to person, but vigilance is necessary to detect any viral evolution that could change this,” stated Sylvie Briand, the WHO’s pandemic preparedness chief.
Experts are closely monitoring potential changes in the virus that could pose greater risks to humans, urging countries to enhance their monitoring capabilities, Briand added. This is particularly crucial as the virus now affects countries with limited prior experience in avian flu surveillance.
Devastating impact on birds
According to the WHO, since 2020, a variant of the virus has caused an “unprecedented” number of deaths in wild birds and poultry across various countries in Africa, Asia, and Europe.
In 2021, the virus spread to North America and subsequently reached Central and South America in 2022.
Last year, highly pathogenic H5N1 bird flu outbreaks were reported in 67 countries across five continents, resulting in the loss of over 131 million domestic poultry due to death or culling on affected farms and in villages.
In 2023, an additional 14 countries reported outbreaks, primarily in the Americas, indicating the continued spread of the disease.
These outbreaks have caused extensive damage to poultry populations, devastating farmers’ livelihoods and impacting the food trade, according to the WHO.
The UN health agency also noted several instances of mass bird deaths, highlighting that while primarily affecting animals, these outbreaks pose ongoing risks to humans.
“The epidemiology of H5N1 continues to rapidly evolve,” remarked Keith Sumption, the FAO’s chief veterinary officer. He appealed for the timely sharing of genetic sequences to facilitate monitoring for changes, ultimately enhancing risk assessment and disease control efforts.
