Geneva – The H5N1 virus bird fluwith a high mortality rate in humans although with a contagion rate limited for now, is rapidly expanding to continents such as the American continent due to factors such as climate changehighlighted this Wednesday an expert from the World Health Organization (WHO).
“Climate change has impacted the routes of migratory birds, and this has played a role in the unprecedented spread of H5N1 in animals,” the head of the WHO's global influenza prevention program, Zhang Wenqing, stressed at a press conference.
The expert stressed that the 2.3.4.4b variant of the virus “emerged in 2020, crossed the Atlantic in 2021 to North America and in 2022 reached South America”, with various outbreaks observed in recent years not only in birds, but also in mammals.
The recent detection of outbreaks of avian flu in cattle and goats in USAwhich has caused the first cow-to-man infection ever recorded on a farm, has increased the concern of the medical community about the possible mutations of this virus, which according to the WHO has epidemic and pandemic potential.
The head of emerging diseases and zoonoses at the WHO, María Van Kerkhove, added that since 2021 only 28 cases of avian flu have been detected in humans, but the increase in outbreaks in animals has led the health agency to maintain for seven years a global surveillance system, as well as development programs for possible vaccines.
“Although there is currently no transmission between humans, we are concerned about the virus, because we know that the flu has the potential to cause epidemics and pandemics, that is why we maintain the system”remarked the person also responsible for the WHO response against Covid-19.
Last week, the WHO stated that the H5N1 virus has also been found in the milk of cattle and goats infected by the outbreaks in the United States, which is why it insisted on maintaining food safety practices such as the exclusive consumption of pasteurized dairy products. .
Faced with millions of birds infected and dying in the last two decades by H5N1, cases in humans remain rare (about 900 since 2003), although the high level of lethality that the disease currently has in humans is worrying, since more Half of the infections have been fatal for the patient.
The WHO recognizes an “exponential growth” since 2020 in the number of infections in birds, in addition to more and more mammals affected, including seals, mink, sea lions, foxes and since recent weeks also cattle and goats.
“Detection in dairy cattle does not change our risk assessment, but it is worrying that this epizootic (epidemic in animals) has occurred under our noses during the covid pandemic,” highlighted the expert.