At least eight types of bird flu that can kill humans are spreading in factory farms around the world - they may be more severe than Covid-19

Last modified on Friday, October 29, 2021 07.33 EDT

One day in December last year, 101,000 chickens on a huge farm near the city of Astrakhan in southern Russia began to collapse and die. Tests by the National Research Center showed that a relatively new and deadly avian influenza virus called H5N8 was spreading. Within days, 900,000 birds at the Vladimirskaya factory were urgently slaughtered to prevent an epidemic.

Avian influenza is another epidemic that continues to circulate in the world. H5N8 is just a strain that has been raging in thousands of chickens, ducks and turkey flocks in nearly 50 countries/regions including the United Kingdom in recent years. Signs of stopping.

But the Astrakhan incident was different. When testing 150 workers on the farm, it was found that 5 women and 2 men had the disease, although the symptoms were mild. This is the first time that H5N8 has jumped from birds to humans.

The World Health Organization (WHO) has received the alert, but at the height of the Covid-19 pandemic, even Anna Popova, the chief consumer adviser of the Russian Federation, warned on television that “to a certain extent, the interpersonal relationship of H5N8 The possibility that the spread will evolve soon", work on vaccine development should begin immediately.

Global attention is focused on the origin of Covid-19, whether in nature or in the laboratory, but there are now eight or more variants of avian influenza, all of which can infect and kill humans, and may More serious than Covid-19 Factory farms around the world often rattle, and the government hardly notices.

There were no further reports of human H5N8 infection in 2021, but last week’s concerns turned to China. Since its first detection in 2014, another avian flu called H5N6 has infected 48 people. Most of the cases are related to staff breeding birds, but there has been a surge in recent weeks, and more than half of the infected people have died, indicating that H5N6 is accelerating, mutating and extremely dangerous.

The WHO and Chinese virologists are already worried enough and call on governments to be more vigilant. "The possibility of human-to-human transmission is low [but] there is an urgent need for more extensive geographic monitoring in China's affected areas and nearby areas to better understand the risks and the recent increase in human transmission," WHO The Pacific region said the spokesperson in a statement.

Earlier this month, the Chinese Center for Disease Control and Prevention [CDC] discovered several mutations in the two recent H5N6 cases. Gao Fu, director of the CDC, and Shi Weifeng, dean of the School of Public Health of Shandong First Medical University, said the spread of the H5N6 virus now poses a “serious threat” to the poultry industry and human health. "The zoonotic potential of AIVs [avian influenza viruses] requires continuous and vigilant monitoring to avoid further spillovers that could lead to catastrophic pandemics," they said.

WHO suspects but has no evidence that Covid-19 is related to the intensive animal farming of many almost unregulated wildlife farms in Southeast Asia. The major epidemics in the past 30 years, including the outbreak of Q fever and highly pathogenic avian influenza in the Netherlands, are all related to intensive animal husbandry. The government and the 150 billion pounds a year poultry and livestock industry emphasize that intensive agriculture is usually extremely safe and is now essential to provide protein for a rapidly growing population, but scientific evidence shows that stressful and crowded environments can cause many infectious diseases The emergence and spread of. Diseases and act as an "epidemiological bridge" between wild animals and human infections.

United Nations agencies, scholars and epidemiologists recognize the connection between the emergence of highly pathogenic avian influenza viruses and the increasing intensive poultry farming. According to the Food and Agriculture Organization of the United Nations (FAO): “Avian influenza virus is evolving into a huge and diverse virus gene bank... The pathogen may become a highly virulent pathogen; In the single breeding of genetically identical animals with high feed conversion rate, a newly emerged highly virulent pathogen will spread rapidly in a flock or cattle herd.” The government and industry often accuse wild birds of migrating routes. It spreads bird flu, but more and more evidence shows that intensive farms are potential "mixing tanks" for new deadly viruses.

"The accusation of migrating waterfowl... is clearly no longer a valid position," said Rob Wallace, an American virologist, who believes that emerging influenza viruses are adapting to industrialized poultry production. "Influenza has penetrated industrial livestock and poultry so thoroughly that these farms now serve as their own [disease] reservoirs," he said. "They are their own source."

Wallace said that there are more than 20 billion chickens and nearly 700 million pigs being raised at any one time, and there is a high probability that new influenza virus strains and variants will appear and spread to humans.

He is supported by Sam Shepard, a biologist at the University of Bath. He said that overuse of antibiotics, overcrowding, and genetic similarities between animals have provided many bacteria, viruses, and other pathogens to fuse, mutate, spread, and then jump into humans. Ideal conditions.

Sheppard studied how keeping animals together can cause genetic changes in common pathogens such as Campylobacter, which is now common in poultry, pigs, and cattle. "These first appeared in the 20th century and coincided with a significant increase in the number of farmed cattle. Due to excessive drug use, these bugs are now resistant to antibiotics," he said.

It's not just poultry and pigs. The emergence of respiratory diseases such as Mers in camels, coronaviruses in mink farms, and BSE in cattle indicate that the intensive farming of any animals will increase the risk of infection.

Marius Gilbert, an epidemiologist at the Free University of Brussels in Belgium, and others have shown that avian influenza is related to the rapid intensification of poultry farming, which makes the avian influenza virus more dangerous now.

Public health experts have long warned of the dangers of industrialized agriculture, but since Covid, as the full cost of the modern pandemic is seen, the risks have become higher. Doctor of Medicine and historian Michael Gregg said he was The author of the book "Influenza: Our Virus". Hatch yourself.

Greg believes that human diseases have gone through three eras: First, we started domesticating animals about 10,000 years ago and contracted their diseases, such as measles and chickenpox; then in the 18th and 19th centuries, the industrial revolution led to diabetes, obesity, The prevalence of heart disease and cancer; and now, due to the intensification of agriculture, zoonotic or animal-borne diseases such as avian influenza, Salmonella, Mers, Nipah and Covid-19 are caused.

"From an evolutionary perspective, raising poultry, cattle, and pigs under high-intensity, crowded, enclosed, and completely unnatural conditions may be the most profound change in the relationship between humans and animals in 10,000 years," he said

"We have seen an unprecedented outbreak of a new bird flu virus. This is the greatest pandemic risk in history, and it is certainly likely to be more serious than Covid."

Gilbert said that not only is factory farming causing dangerous bird flu, but humans are also making changes to the wider environment. "Most viruses that spread in wild birds are very low-risk and have only minor effects. [But] they enter the poultry system from time to time, where they undergo evolutionary changes, mainly related to the conditions in which the animals are kept. We have Seeing that the low pathogenic virus has gained pathogenicity in the farm."

He said this may form a vicious circle, where the virus mutates on farms and then spills into wild bird populations, where it can spread further through migration. "Every time people are infected, there is a danger of the virus becoming more dangerous or spreading." Register for the monthly update of Animal Breeding, learn about the world's largest breeding and food story, and keep up with our investigations. You can send your stories and ideas to animalsfarmed@theguardian.com