Avian influenza spreads via migratory bird flyways, impacting wildlife globally. Water, viruses, and species are intertwined. World Migratory Bird Day in 2023 recalls the urge for prevention. Analysis.
By Dr. Sarah Olson, Director of Health Research at WCS (Wildlife Conservation Society) and Member of the Steering Committee of PREZODE.
As we observe World Migratory Bird Day in 2023, the chosen theme, ‘Water,’ ripples with profound significance. Water, in its various forms, serves as both a barrier and a facilitator in birds’ extraordinary travels. Oceans, rivers, lakes, and wetlands are indispensable waypoints for these resilient travelers, shaping their migratory routes while also creating aerial superhighways for opportunistic, hitchhiking pathogens to travel the globe.
Astounding breadth of species impacts
Historically, these hitchhikers were predominantly low-pathogenic avian influenza viruses, meaning they did not cause high mortality in wild birds. Then, about two years ago, a highly pathogenic lineage of avian influenza took advantage of the flyways and became an unprecedented global pandemic. Likely millions of wild birds have been killed worldwide, and the breadth of species impacts has been astounding:
As the virus traversed continents, it crossed species barriers:
The Growing Threat of Avian Influenza
For good reasons, scientists are advocating a watchful approach. Since 1900, avian influenza has caused five human pandemics, nearly all tracing back to an animal source with the largest in 1918 killing an estimated 50 million people. In the last two decades there have been hundreds of isolated human fatalities of people exposed to sick animals. So far these spillover events have been self-limiting, and virologists point out that its ability to transmit among mammals is concerning but not yet reason to panic. The contemporary lineage that is wreaking havoc spent 25 years evolving in poultry, resulting in deaths of at least 400 million domestic animals and US$20 billion of economic losses. In recent years it was likely responsible for egg and turkey shortages and rationing in your local grocery store.
Moving Beyond Surveillance: A Call for Systemic Change
Beyond watchful waiting, efforts like Preventing ZOonotic Disease Emergence (PREZODE) are advocating salient steps to address the emergence of viruses at the source. The current avian influenza pandemic demands a reevaluation of our food systems and practices. Wild birds and mammals are the most current victims of our unsafe and unsustainable agricultural practices. If business as usual continues, there is a risk we could be next and victims of our own industrial food animal production. It is clear that human intensification of poultry farming contributed to the emergence and spread of the virus. Prevention initiatives like PREZODE are needed to bring public, conservation and livestock sectors together so that better policies are informed by health risks and costs alongside the economic drivers and constraints of the industry. We need to consider a reorientation of our approach to food production and promote sustainable practices that prioritize the health of ecosystems, all animals, and the well-being of humans.
The challenge at hand is not one that any nation or community can face alone. World Migratory Bird Day 2023 is a yearly reminder of the need for both international collaboration and action. Yes, it is imperative that we all work to increase surveillance of avian influenza virus in animals to track the continuing evolution and impacts of the pathogen. Moreover, the mass mortalities and frequency of outbreaks of migratory birds and other animals from this virus are sending us an urgent message. We are in troubled waters and we need more than watchful waiting.
Efforts like PREZODE that get to the source and help foster better food industry practices and policies are the only path to smoother water. Governments, NGOs, scientists, and communities must come together to implement prevention strategies, reevaluate food systems, and safeguard the health of our shared environment for generations to come.