The COVID-19 pandemic, which has killed more than 21 million people, has elevated an existential question into concrete immediacy. After COVID-19, when will the next pandemic of a highly deadly nature strike again?
The first-ever widespread global epidemic of monkeypox affected several countries on almost every continent. It was as if the world had dodged a bullet when the cases began to subside. Additionally, the outbreak of the extremely deadly Ebola Sudan virus in Uganda threatened the region and beyond as it spread through the densely populated capital of Kampala. These potential crises have appeared much more frequently in recent years, making new pandemics an inescapable risk for the world’s population.
The first new pandemic after COVID-19, which continues to infect billions, may already be in plain sight, but mostly ignored or dismissed by most media and without any political attention.
The largest outbreak of highly pathogenic avian influenza (HPAI) on record has killed millions of birds since October 2021. As a result of the disease and related culling, over 140 million poultry, including 60 million in North America and 48 million in Europe, have been killed, according to the World Organization for Animal Health (WOAH).
Genetic analysis of the H5N1 influenza virus in the current avian pandemic has located it to a clade (family of viruses) circulating among poultry and wild birds on several continents, but most closely related to strains among seabirds Europeans.
The first cases in North America were detected in December 2021 in Newfoundland and Labrador, Canada, at a bird farm. In February 2022, Florida’s Fish and Wildlife Conservation Commission reported that black vulture deaths in Hontoon Island State Park were caused by the same virus.
Over the following months, the virus spread to many species of wild birds, commercial poultry, as well as mammals including grizzly bears, red foxes, coyotes, seals and dolphins, as well as a human case confirmed on April 27 by the United States. Centers for Disease Control and Prevention (CDC) in an incarcerated person in Colorado who had been involved in the slaughter of infected poultry.
In February 2022, the the wall street journal noted that bird flu had affected a chicken farm in Fulton, Ky., and a Tyson Foods chicken processing farm, raising concerns of a repeat of the last major bird flu calamity in 2015.
Egg prices rose almost 60% in December, compared to the previous year, with egg stocks down 29%. Currently, Nebraska has recorded 6.7 million poultry deaths, up from 4.8 million during the 2015 outbreak. According to the Log, Colorado has lost 90% of its laying hens.
As disastrous as the outbreak has been for the bird population, the fear remains that the virus will learn to effectively use a human host to transmit itself. So far, according to the World Health Organization (WHO), between 2003 and March 2022, there have been only 864 cases of H5N1 in humans in 18 countries around the world. The infection in the United States was the first time for that country.
The death rate, however, is dangerously high with 456 deaths among the 864 cases, giving a 53% chance of dying if infected. So far, cases have remained sporadic, in small clusters, involving exposure to infected poultry or contaminated environments.
But scientists are increasingly concerned that a more virulent form of the virus could suddenly evolve and spread rapidly through the human population as a deadly airborne pathogen. Wend Blay Puryear, a molecular virologist at Tufts University, told the Guardian, “There are fears that it has pandemic potential. Before COVID was on anyone’s radar, this was the one we were all watching closely.
As a recent report in Think global health noted: “Any time one species transmits the virus to another, it constitutes a spillover event. These multiple spillovers – among wild bird species, from wild birds to domestic birds, from birds to mammals, and from animals to humans – raise serious concerns about the adaptive and evolutionary potential of this influenza lineage and the risk continuum associated with avian migration. . Understanding which species among these many hosts can help the virus adapt is crucial for targeted monitoring and mitigation efforts.
The last pandemic to cause such massive devastation to birds began in December 2014, when more than 50 million birds died, costing farmers more than $1.6 billion. However, in the summer of 2015, the virus suddenly disappeared as quickly as it appeared. Migratory birds returning to Canada have been found to be virus free.
However, in the present case, the epidemic was maintained throughout the summer and increased again this winter. Active surveillance has identified more than 3,300 infected birds across 100 species, an immense scale of transmission compared to the 2014-2015 outbreak, when fewer than 100 wild birds tested positive for H5N1.
A Colorado Department of Agriculture veterinarian, Maggie Baldwin, told the Log, “One of the challenges is that we don’t know why it [the virus] has been able to thrive for so long. We are almost a full year into this outbreak and it is continuing. »
Mike Tincher, rehabilitation coordinator for Colorado’s Rocky Mountain Raptor program, said, “There is no historical context for this. It’s like when COVID hit humans… We’ve never seen that before. And it just doesn’t slow down.
As the US Department of Agriculture recently noted, “wild birds can be infected with HPAI and show no signs of disease. They can carry the disease to new areas during migration, potentially exposing domestic poultry to the virus. Such asymptomatic the spread of the virus represents an exceptional challenge for the international community unless surveillance systems are strengthened in the animal and human sectors.
A recent report from Eurosurveillance attracted a lot of attention on social media. He describes the outbreak of HPAI H5N1 in intensively farmed mink in the Galicia region of northwestern Spain in October 2022. Professor of Evolution and Genomics at the University of Oxford Aris Katzourakis tweeted, “[I] don’t understand how mink farming can be defended. Viruses move easily between mink and humans, and this could play a big role in the emergence of future pandemics.
When the initial outbreak occurred, veterinarians assumed the illness was caused by SARS-CoV-2, as it had already hit mink farms in Denmark in November 2020. However, lab tests revealed that the culprit was HPAI H5N1. More than 52,000 mink on the farm had to be slaughtered.
As the Eurosurveillance According to the report, the mink were kept in open barns and fed raw fish and poultry by-products from the same region. Their detailed analysis revealed that the virus was similar to the virus circulating among birds on several continents.
A Science the article published this week on the outbreak of avian flu in Spanish mink farms states: “The virus is not known to spread well between mammals; people almost always catch it from infected birds, not each other. But now H5N1 appears to have spread through a densely populated mammalian population and acquired at least one mutation that promotes mammal-to-mammal spread. Virologists warn that H5N1, which is now rampant among birds around the world, could invade other mink farms and become even more transmissible.
Tom Peacock, a virologist at Imperial College London, warned: ‘This is incredibly concerning. This is a clear mechanism for an H5 pandemic to occur.
The mutation in question is uncommon and has only been seen once before, in a European polecat, according to CIDRAP. The mutation may have evolved spontaneously in mink in a convergent evolutionary pathway. The new variant, labeled 2.3.4.4b, appeared in Europe in late 2020 and has become predominant among wild birds. It is thought to have originated in Korea as a result of a reassortment process between H5N1 and clade 2.3.4.4b H5N8.
Although the mutation appears to be less pathogenic for humans, around six people have so far caught the virus and one has died. It also seems more suitable for all birds, as noted by influenza researcher Richard Webby. It is worrying that in this resurgence of H5N1, many species of mammals have been infected.
Thomas Mettenleiter, director of the Friedrich Loeffler Institute, addressing Science on the low pathogenicity (lethality) of the new strain in humans, explained: “Of course, this can also be bad news, because it could facilitate the spread of the virus under the radar, giving it more possibilities of to evolve. ”