By Francis Allan L. Angelo
As the influenza A(H5N1) virus continues to spread among animals and occasionally infect humans, global health agencies are closely monitoring the situation to assess public health risks.
According to a recent joint assessment by the Food and Agriculture Organization (FAO), the World Health Organization (WHO), and the World Organisation for Animal Health (WOAH), the global risk to public health from these viruses remains low, although the situation demands vigilance.
The report, which analyzes data up to July 18, 2024, underscores the increasing genetic diversity and geographic spread of A(H5N1) viruses, particularly those belonging to clade 2.3.4.4b.
Since their emergence in 2020, these viruses have caused significant die-offs among wild birds and outbreaks in poultry worldwide.
Additionally, the virus has spilled over into non-avian species, including domestic mammals such as cats and dogs, as well as marine mammals.
Human infections remain relatively rare, with only 35 cases reported globally since 2021, and no sustained human-to-human transmission has been observed.
Most human cases were linked to direct or indirect contact with infected animals, often in environments like live poultry markets or farms.
“Despite the ongoing spread of A(H5N1) viruses, the overall public health impact at a global level is currently minor,” the report noted.
However, the recent detection of A(H5N1) in dairy cattle in the United States has raised concerns. The virus has been found in 162 dairy herds across 13 states, leading to illness in cattle and associated deaths in other animals, including cats fed on contaminated milk.
“This is a new development that requires careful monitoring,” the report emphasized.
Human cases linked to these dairy cattle infections have been documented, but these were mild and did not lead to further transmission.
Global health agencies stress the importance of preventive measures, including the use of personal protective equipment by those in close contact with infected animals, to mitigate the risk of transmission to humans.
The report also calls for increased surveillance and timely sharing of data to better understand and control the spread of the virus.
