A study from the University of California, Davis, and the National Institute of Agricultural Technology (INTA) in Argentina reveals that the highly contagious H5N1 avian influenza virus has evolved to transmit among birds and marine mammals, presenting a direct risk to wildlife conservation efforts.
The study, published in the journal Emerging Infectious Diseases, is the first genomic characterization of H5N1 in marine wildlife on the Atlantic shore of South America.
For the study, scientists collected brain samples from four sea lions, one fur seal, and a tern found dead at the most affected sea lion rookery in Argentina. All tested positive for H5N1.
Genome sequencing revealed that the virus was nearly identical in each of the samples. The samples shared the same mammal adaptation mutations that were previously detected in a few sea lions in Peru and Chile, and in a human case in Chile. Of note, the scientists found all these mutations also in the tern, the first such finding.
“This confirms that while the virus may have adapted to marine mammals, it still has the ability to infect birds,” said first author Agustina Rimondi, a virologist from INTA. “It is a multi-species outbreak.”
We know this because the virus sequence in the tern retained all mammal-adaptation mutations. Such mutations suggest a potential for transmission between marine mammals.
“This virus is still a relatively low risk for humans,” said senior author Marcela Uhart, a wildlife veterinarian with the UC Davis School of Veterinary Medicine’s One Health Institute and director of its Latin America Program within the Karen C. Drayer Wildlife Health Institute. “As long as the virus continues to replicate in mammals, it may make it a higher concern for humans. That’s why it’s so important to conduct surveillance and provide early warning.”
The journey of H5N1
Uhart calls clade 2.3.4.4b — the current variant of H5N1 – “this new monster.” It emerged in 2020, while the human world was reeling from a different pandemic, COVID-19. Avian influenza began killing tens of thousands of sea birds in Europe before moving to South Africa. In 2022, it entered the U.S. and Canada, threatening poultry and wild birds. It migrated to Peru and Chile in late 2022.
Then, almost exactly a year ago, in February 2023, highly pathogenic avian influenza entered Argentina for the first time. But it was not until August 2023 — when the virus was first found in sea lions at the tip of South America on the Atlantic coastline of Tierra del Fuego — that the virus unleashed its fatal potential in the region. From there, it moved swiftly northward, with deadly results, first for marine mammals and later for seabirds.
A recent paper Uhart co-authored showed a large outbreak killed 70% of elephant seal pups born in the 2023 breeding season. Mortality rates reached at least 96% by early November 2023 in the surveyed areas of Península Valdés in Argentina.
“When it first came to Argentina, we didn’t know if it would affect elephant seals,” Uhart said. “We never imagined the magnitude of what was to come.”
Since 2022, H5N1 in South America has killed at least 600,000 wild birds and 50,000 mammals, including elephant seals and sea lions in Argentina, Chile, and Peru, and thousands of albatrosses in the Malvinas/Falkland Islands.
Moving south
The virus is now heading southward from South America, and scientists are deeply concerned about its potential impact on penguins and other wildlife in Antarctica.
Uhart and Ralph Vanstreels, her colleagues at UC Davis’ Latin America Program in the School of Veterinary Medicine, are conducting wildlife surveillance for H5N1 in Antarctica this month.
“We need to keep an eye on the ability of this virus to reach species that have never been exposed to an H5N1 infection before,” Rimondi said. “The consequences in those species can be very severe.”
The concept of One Health honors the interconnectivity among humans, domestic animals, wildlife, and the environment. Interspecies disease outbreaks are unsettling examples of such connections and require global collaboration among public, wildlife, agricultural, health, and other sectors.
“We are trying to be at the forefront of documenting, recording, and providing early warning,” Uhart said. “We’ve been in this area for 30 years. We know these species. We work with scientists who have 30 years of data on these populations, so we can know what will be important for the future. We have to give voice to these poor creatures. Nobody’s taking note of how big this is.”
Reference: “Highly Pathogenic Avian Influenza A(H5N1) Viruses from Multispecies Outbreak, Argentina, August 2023” by Agustina Rimondi, Ralph E.T. Vanstreels, Valeria Olivera, Agustina Donini, Martina Miqueo Lauriente and Marcela M. Uhart, April 2024, Emerging Infectious Diseases.
DOI: 10.3201/eid3004.231725
News
Completely New Use Discovered – This Traditional Herb Has Remarkable Nerve Regenerative Properties
Blessed thistle (Cnicus benedictus), a member of the Asteraceae family, thrives in our climate. This plant has been utilized for centuries as a medicinal herb, often consumed as an extract or tea to support [...]
Scientists study lipids cell by cell, making new cancer research possible
Imagine being able to look inside a single cancer cell and see how it communicates with its neighbors. Scientists are celebrating a new technique that lets them study the fatty contents of cancer cells, [...]
Antibiotic Breakthrough: Revolutionary Chinese Study Paves Way for Superbug Defeating Drugs
New research reveals that fluorous lipopetides act as highly effective antibiotics. Bacterial infections resistant to multiple drugs, which no existing antibiotics can treat, represent a significant worldwide challenge. A research group from China has [...]
Signs of Multiple Sclerosis Show Up in Blood Years Before Symptoms Appear
UCSF scientists clear a potential path toward earlier treatment for a disease that affects nearly 1,000,000 people in the United States. By Levi Gadye In a discovery that could hasten treatment for patients with multiple [...]
Advanced RNA Sequencing Reveals the Drivers of New COVID Variants
A study reveals that a new sequencing technique, tARC-seq, can accurately track mutations in SARS-CoV-2, providing insights into the rapid evolution and variant development of the virus. The SARS-CoV-2 virus that causes COVID has the unsettling [...]
No More Endless Boosters? Scientists Develop One-for-All Virus Vaccine
End of the line for endless boosters? Researchers at UC Riverside have developed a new vaccine approach using RNA that is effective against any strain of a virus and can be used safely even by babies or the immunocompromised. Every [...]
How Are Hydrogels Shaping the Future of Biomedicine?
Hydrogels have gained widespread recognition and utilization in biomedical engineering, with their applications dating back to the 1960s when they were first used in contact lens production. Hydrogels are distinguished from other biomaterials in [...]
Nanovials method for immune cell screening uncovers receptors that target prostate cancer
A recent UCLA study demonstrates a new process for screening T cells, part of the body's natural defenses, for characteristics vital to the success of cell-based treatments. The method filters T cells based on [...]
New Research Reveals That Your Sense of Smell May Be Smarter Than You Think
A new study published in the Journal of Neuroscience indicates that the sense of smell is significantly influenced by cues from other senses, whereas the senses of sight and hearing are much less affected. A popular [...]
Deadly bacteria show thirst for human blood: the phenomenon of bacterial vampirism
Some of the world's deadliest bacteria seek out and feed on human blood, a newly-discovered phenomenon researchers are calling "bacterial vampirism." A team led by Washington State University researchers has found the bacteria are [...]
Organ Architects: The Remarkable Cells Shaping Our Development
Finding your way through the winding streets of certain cities can be a real challenge without a map. To orient ourselves, we rely on a variety of information, including digital maps on our phones, [...]
Novel hydrogel removes microplastics from water
Microplastics pose a great threat to human health. These tiny plastic debris can enter our bodies through the water we drink and increase the risk of illnesses. They are also an environmental hazard; found [...]
Researchers Discover New Origin of Deep Brain Waves
Understanding hippocampal activity could improve sleep and cognition therapies. Researchers from the University of California, Irvine’s biomedical engineering department have discovered a new origin for two essential brain waves—slow waves and sleep spindles—that are critical for [...]
The Lifelong Cost of Surviving COVID: Scientists Uncover Long-Term Effects
Many of the individuals released to long-term acute care facilities suffered from conditions that lasted for over a year. Researchers at UC San Francisco studied COVID-19 patients in the United States who survived some of the longest and [...]
Previously Unknown Rogue Immune Key to Chronic Viral Infections Discovered
Scientists discovered a previously unidentified rogue immune cell linked to poor antibody responses in chronic viral infections. Australian researchers have discovered a previously unknown rogue immune cell that can cause poor antibody responses in [...]
Nature’s Betrayal: Unmasking Lead Lurking in Herbal Medicine
A case of lead poisoning due to Ayurvedic medicine use demonstrates the importance of patient history in diagnosis and the need for public health collaboration to prevent similar risks. An article in CMAJ (Canadian Medical Association [...]