Avian influenza, popularly known as bird flu, is a disease that primarily infects birds. It consists of a high and low classified pathogenicity. The low pathogenicity classification often presents mild illness with unnoticed symptoms. The high pathogenicity causes severe illness, spreads rapidly, and has a high mortality rate among many species of birds. H5N1 is the most well-known high-pathogenicity strain of bird flu.
The Growing Danger of H5N1
Less than 1,000 humans have contracted H5N1 since 1997. Although infrequent, when H5N1 has crossed over to human infections, it has a 56% mortality rate. Compare that to the coronavirus’s 1-2% worldwide mortality rate. The saving grace, thus far, regarding H5N1’s crossover to humans has been its inability to spread rapidly among humans.
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An escalating concern among scientists is the recent rate of change in H5N1’s spread among migratory birds and mammals. The risk of a potential variant leaping to humans is increasing. In 2022 the US experienced its largest outbreak of H5N1 avian flu to date, resulting in the death of 58 million birds, primarily commercial. Every state in the country experienced a measure of this outbreak. This is one of the leading causes of why the price of eggs is so high for consumers in early 2023.
In January 2023, the Pan American Health Organization issued an alert after detecting the increasing presence of avian flu outbreaks in birds among ten countries in the region of the Americas. This alert included the detection of one human infection of the high pathogenicity classification of bird flu in South America in January 2023 and another in North America in April 2022. In January 2023 alone, the World Organization for Animal Health recorded 70 outbreaks across three continents, resulting in the culling of three million birds in a three-week reporting period.
The spread of the disease among humans is currently difficult, but scientists warn that risks remain.
As the H5N1 strain ravaged bird populations since 2020, including poultry and wild birds, there has been increased recorded spillover among mammals, including foxes, raccoons, tigers, and bears. It is assumed these mammals fed on infected wild birds. Recently, H5N1 spread through an entire mink farm of 50,000 in Spain. Avian flu has been detected among 120 wild mammals in the US alone. In the last month, the disease has been detected among seals in Scotland and sea lions in Peru.
A potential for concern among scientists is that mammals, such as dogs or cats who have contracted the coronavirus, could also contract H5N1 and provide the springboard for the deadly strain of avian flu to pass to and among humans. That is only a theoretical concern so far. Presently, there are no recorded instances of H5N1 passing from person to person, only from animal to people.
One of the critical reasons for H5N1’s surge in recent decades is the nature of the world food system. As the global population has surged, the nature of food harvesting and distribution has shifted. During the 1990s, the world’s poultry population grew 76% in developing countries, 23% in developed countries. The poultry farms of the developing world provided a fertile environment for H5N1 to grow while wild migratory birds carried this deadly avian flu across the globe.
Is There A Vaccine for Avian Flu?
Yes, but as a recent editorial in the New York Times observed, the current US stockpile is nowhere near enough if an outbreak occurred.
The only company with an F.D.A.-approved non-egg-based H5N1 vaccine expects to be able to produce 150 million doses within six months of the declaration of a pandemic. But there are seven billion people in the world.
Click on the avian flu timeline infographic for a larger image.
Avian flu is the “big one!” It is a potential ticking time bomb existing right under our noses and most are unaware it is out there. Even worse, it is trending in a dangerous direction. Bookmark our monthly tracker here to follow monthly reports and insights regarding avian flu’s expansion across the globe.