The human patient had a mutation, PB2 E627K, which is linked to the virus adapting to mammalian hosts
Photo for representation: iStock
The recent confirmation of a second human case of H5N1 avian influenza in the United States has reignited anxieties about a potential bird flu pandemic. This follows months of widespread outbreaks in wild birds and poultry flocks, causing significant economic damage and raising concerns about the virus's potential to jump species.
On April 1, 2024, a case of a Texas dairy worker contracting H5N1 after exposure to infected cows was reported, raising questions about the virus’s potential for human-to-human transmission. A dozen cow herds in six states and three cats in Texas have also died due to infection.
The White House, on April 3, 2024, said it is closely tracking and monitoring the situation. The US reported its first-ever human case of H5N1 bird flu in 2022.
Read more: First cases of avian flu found in Antarctic region
Meanwhile, the virus may be fast spreading in Antarctic Peninsula region. An expedition of scientists from Federation University, Australia found the carcasses of 532 Adélie penguins on a small part of an island, and suspect the casualties may be much higher, going into several thousands.
Although the researchers believe this was caused by high-pathogenicity avian influenza, virus presence has not been confirmed and additional testing will be conducted in the coming months to determine the cause of death.
The human patient had a mutation, PB2 E627K, which is linked to the virus adapting to mammalian hosts, according to US Centers for Disease Control and Prevention (CDC). The development is concerning, as bird flu viruses typically don’t infect humans. However, rare cases of human infection have occurred with some of these viruses, according to CDC. However, the mutation has been detected earlier.
“Overall, the genetic analysis of HPAI A(H5N1) viruses in Texas supports CDC’s conclusion that the human health risk currently remains low,” CDC said in a statement.
Read more: We should only worry about bird flu making us sick when we see human-to-human transmission
However, some experts have raised concerns regarding the virulence and mortality of the virus, warning about a bird flu pandemic. According to United Kingdom based news website Daily Mail, experts have warned that a bird flu pandemic could be “100 times worse than COVID” and kill up to half of those infected.
“'I think this is a virus that has the greatest pandemic threat [that is] playing out in plain sight and is globally present,” Dr Suresh Kuchipudi, a bird flu researcher in Pittsburgh, was quoted as saying by the Daily Mail report.
The report also mentioned that the infection has been observed in various mammals such as cows, cats, and humans, which raises concerns about the virus potentially mutating to become more easily transmissible, the report added. However, other experts have also pointed out it was too early to panic because there were still too many unknowns about recent cases to warrant sounding an alarm, it added.
The virus has long been on the radar of experts as a pandemic risk.
Read more: French bird flu vaccine for ducks may be launched soon
A recent study, published in journal Emerging Infectious Diseases, indicated that the avian influenza A virus subtype H5N1 entered a significant panzootic phase between 2020 and 2023, akin to a pandemic within the animal kingdom.
Researchers analysed data on infected mammals from 59 scientific articles spanning two distinct periods: 2020–2023 and 2003–2019. The study highlights the potential risks posed to human health by mammalian adaptation of the virus, noting a lack of comprehensive information on the current panzootic event (2020–2023).
In 2005, the World Health Organization (WHO) and influenza experts worldwide had expressed concerns over the spread of the avian flu virus. The global health agency predicted that, even in the best-case scenarios, the pandemic could lead to 2 to 7 million deaths and tens of millions needing medical care.
According to a 2007 research paper published in International Journal of Health Sciences, “The first ominous sign that avian influenza viruses (H5N1) could directly infect humans from avian species on a large scale occurred in 1997 in Hong Kong, resulting in 18 documented cases and six fatalities.”
Read more: Learning from COVID-19: Here’s what is needed to prepare for the next global health emergency
India reported its first and only case of human avian influenza A(H5N1) in Haryana on July 21, 2021.
The current strain causing worry, H5N1, has been circulating aggressively in birds across the globe since late 2021. Wild birds are natural carriers of this virus, and their migratory patterns contribute to its rapid spread. This has resulted in a significant increase in confirmed bird flu cases compared to past years. Since January 1, 2022, the US Department Of Agriculture has reported close to 9,500 cases in wild birds.
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