Frequent reports of flu being detected in birds and other animals spark fear that avian influenza could cause the next pandemic.

Amid the ongoing battle against COVID-19, another virus looms on the horizon, reminding everyone of the potential dangers of animal-to-human transmission. Bird flu, or avian influenza, has resurfaced with alarming intensity, raising concerns about a possible global pandemic, according to the University of Cambridge.

The first significant alarm was raised in Hong Kong in 1997 when 18 people were infected with bird flu, resulting in six fatalities. This marked the first time the highly infectious H5N1 disease had jumped to humans, igniting urgent attention from influenza researchers studying animal-to-human transmission. The strain observed in Hong Kong had a mortality rate of one-third among those infected. The potentially catastrophic consequences of direct human-to-human transmission became a pressing concern.

Bird flu is classified by the World Health Organization (WHO) as a major pandemic threat, and the world is currently facing the most severe bird flu epidemic to date. Over the past year, there have been unprecedented outbreaks of bird flu on farms worldwide, leading to the death of more than 140 million poultry due to the disease or related culling since October 2021, according to the World Organization for Animal Health.

The scale and speed of this latest strain of bird flu are alarming. It exhibits unusually high fatality rates across a wide range of bird species and demonstrates enhanced transmissibility between them. While the origin of the virus remains unclear, a significant epidemic among wild birds has been identified as the primary source of infections on farms, placing immense pressure on farmers and posing a threat to our food supply.

The impact on wild bird populations has been devastating, pushing certain species to the brink of extinction. Unprecedented mass mortality events have been observed, with gannets, terns and cranes among the casualties. The severity of the situation has even led to the closure of areas like Lindisfarne due to the high prevalence of wild bird disease on the island.

Transmission of bird flu from wild birds to farmed birds typically occurs through direct contact or via feces in farmyards or feed stores. Poultry farmers are now tasked with implementing rigorous biosecurity measures to prevent contact between their birds and wild birds. This includes the use of netting, keeping birds indoors, employing bird scarers and eliminating attractants like ponds. Failure to maintain proper biosecurity has often been the cause of outbreaks on farms, emphasizing the critical role of human diligence.

Outbreaks on farms appear to exhibit seasonality, aligning with the migration patterns of wild birds. Furthermore, since birds are capable of long-distance flight, the outbreak has spread globally. The dynamics of infection within wild bird populations are still not fully understood, underscoring the necessity of continuous surveillance efforts.

In the United States, the bird flu outbreak reached such a scale that it was deemed the worst outbreak in the country's history. The virus was detected in wild birds across all 50 states, resulting in approximately 58 million bird fatalities, according to the United States Department of Agriculture (USDA). The severity of the situation prompted the testing of vaccines for poultry, as the government sought new strategies to combat the growing outbreak. However, concerns were raised about the potential impact on poultry product exports if commercial birds were immunized.

Experts have speculated that avian influenza could become endemic in the United States, posing long-term threats to food security and the economy. Addressing this multifaceted challenge requires collaboration among federal agencies, state agencies, the agriculture sector, and wildlife management.

While the likelihood of bird flu causing the next pandemic remains uncertain, preparedness for future global health crises is crucial. Professor Derek Smith, Director of the Center for Pathogen Evolution at the University of Cambridge, has emphasized the importance of ongoing vaccine development.

According to him, by identifying key virus variants and creating vaccines that offer broad immunity against multiple strains, we can enhance our readiness for future pandemics. Vaccines have proven to be our best defense, saving countless lives during the COVID-19 pandemic, and there is every reason to believe that they can be developed just as swiftly for future influenza pandemics.