Concerns Raised by World Health Organization over H5N1 Bird Flu
The World Health Organization has expressed deep concerns about the spread of H5N1 bird flu, which has shown an “extraordinarily high” mortality rate among humans, according to the organization’s chief scientist, Jeremy Farrar.
The outbreak, which began in 2020, has resulted in the deaths or widespread culling of tens of millions of poultry. The WHO now warns about the virus’s transmission to several mammal species, even including domestic cattle in the United States. This increased transmission to mammals elevates the risk of potential spillover to humans, endangering global health security.
Unexpected Impact on Mammalian Species
Surprisingly, last month both cows and goats joined the growing list of species affected by H5N1 bird flu. Experts were taken aback by this development, as it was previously believed that these animals were not susceptible to this particular influenza strain. Reports from US authorities also indicate that a person in Texas has recently recovered from bird flu after coming into contact with dairy cattle. Furthermore, 16 herds across six states have been infected, apparently from exposure to wild birds.
A Cordoning Global Zoonotic Animal Pandemic
The A(H5N1) variant of the bird flu has now evolved into a “global zoonotic animal pandemic,” as emphasized by Chief Scientist Farrar. The primary concern remains the virus attaining the ability to infect humans and subsequently achieve human-to-human transmission, which could lead to a devastating global health crisis.
No Evidence of Human-to-Human Transmission Yet
While no evidence of human-to-human transmission has been found so far, infection in humans primarily occurs through contact with sick animals. In the past two decades, hundreds of cases of human H5N1 infection have been reported, showcasing an exceptionally high mortality rate due to the lack of natural human immunity to this virus strain. The World Health Organization has documented 889 cases and 463 deaths caused by H5N1 globally across 23 countries between 2003 and 2024, resulting in a case fatality rate of 52%.
Heightened Risk with Mammalian Infection
The recent case of human infection after contact with an infected mammal in the United States spotlights the increased risk. As this virus is now present in mammalian populations, it approaches closer to humans, creating a potential pathway for human infection. Farrar keenly warns that H5N1 is actively seeking new and novel hosts, underscoring the urgent need for increased monitoring to facilitate quick adaptation detection in case of zoonotic transmission.
Call for Preparedness and Accessible Resources
Farrar emphasizes the necessity of efforts aimed at developing vaccines, therapeutics, and diagnostics for H5N1. Additionally, he stresses the importance of equipping regional and national health authorities worldwide with the necessary capacity to identify and diagnose the virus promptly. This preparedness is crucial to enable an immediate and effective response, ensuring global health security in the event of H5N1 achieving human-to-human transmission. Farrar strongly advocates for equitable access to vaccines, therapeutics, and diagnostics to mitigate the impact of potential outbreaks.
