BEIJING (AP) The hunt for the origins of COVID-19 has gone dark in China, the victim of political infighting after a series of stalled and thwarted attempts to find the source of the virus that killed millions and paralyzed the world for months.
The Chinese government froze meaningful domestic and international efforts to trace the virus from the first weeks of the outbreak, despite statements supporting open scientific inquiry, an Associated Press investigation found. That pattern continues to this day, with labs closed, collaborations shattered, foreign scientists forced out and Chinese researchers barred from leaving the country.
The investigation drew on thousands of pages of undisclosed emails and documents and dozens of interviews that showed the freeze began far earlier than previously known and involved political and scientific infighting in China as much as international finger-pointing.
As early as Jan. 6, 2020, health officials in Beijing closed the lab of a Chinese scientist who sequenced the virus and barred researchers from working with him.
Scientists warn the willful blindness over coronavirus origins leaves the world vulnerable to another outbreak, potentially undermining pandemic treaty talks coordinated by the World Health Organization set to culminate in May.
At the heart of the question is whether the virus jumped from an animal or came from a laboratory accident. A U.S. intelligence analysis says there is insufficient evidence to prove either theory, but the debate has further tainted relations between the U.S. and China.
Unlike in the U.S., there is virtually no public debate in China about whether the virus came from nature or from a lab leak. In fact, there is little public discussion at all about the source of the disease, first detected in the central city of Wuhan.
Crucial initial efforts were hampered by bureaucrats in Wuhan trying to avoid blame who misled the central government; the central government, which muzzled Chinese scientists and subjected visiting WHO officials to stage-managed tours; and the U.N. health agency itself, which may have compromised early opportunities to gather critical information in hopes that by placating China, scientists could gain more access, according to internal materials obtained by AP.
In a faxed statement, China's Foreign Ministry defended Chinas handling of research into the origins, saying the country is open and transparent, shared data and research, and made the greatest contribution to global origins research. The National Health Commission, China's top medical authority, said the country invested huge manpower, material and financial resources and has not stopped looking for the origins of the coronavirus.
It could have played out differently, as shown by the outbreak of SARS, a genetic relative of COVID-19, nearly 20 years ago. China initially hid infections then, but WHO complained swiftly and publicly. Ultimately, Beijing fired officials and made reforms. The U.N. agency soon found SARS likely jumped to humans from civet cats in southern China and international scientists later collaborated with their Chinese counterparts to pin down bats as SARS natural reservoir.
But different leaders of both China and WHO, Chinas quest for control of its researchers, and global tensions have all led to silence when it comes to searching for COVID-19s origins. Governments in Asia are pressuring scientists not to look for the virus for fear it could be traced inside their borders.
Even without those complications, experts say identifying how outbreaks begin is incredibly challenging and that its rare to know with certainty how some viruses begin spreading.
Its disturbing how quickly the search for the origins of (COVID-19) escalated into politics, said Mark Woolhouse, a University of Edinburgh outbreak expert. Now this question may never be definitively answered.
Secrecy clouds the beginning of the outbreak. Even the date when Chinese authorities first started searching for the origins is unclear.
The first publicly known search for the virus took place on Dec. 31, 2019, when Chinese Center for Disease Control scientists visited the Wuhan market where many early COVID-19 cases surfaced.
However, WHO officials heard of an earlier inspection of the market on Dec. 25, 2019, according to a recording of a confidential WHO meeting provided to AP by an attendee. Such a probe has never been mentioned publicly by either Chinese authorities or WHO.
In the recording, WHOs top animal virus expert, Peter Ben Embarek, mentioned the earlier date, describing it as an interesting detail. He told colleagues that officials were looking at what was on sale in the market, whether all the vendors have licenses (and) if there was any illegal (wildlife) trade happening in the market.
A colleague asked Ben Embarek, who is no longer with WHO, if that seemed unusual. He responded that it was not routine, and that the Chinese must have had some reason to investigate the market. Well try to figure out what happened and why they did that.
Ben Embarek declined to comment. Another WHO staffer at the Geneva meeting in late January 2020 confirmed Ben Embareks comments.
The Associated Press could not confirm the search independently. It remains a mystery if it took place, what inspectors discovered, or whether they sampled live animals that might point to how COVID-19 emerged.
A Dec. 25, 2019, inspection would have come when Wuhan authorities were aware of the mysterious disease. The day before, a local doctor sent a sample from an ill market vendor to get sequenced that turned out to contain COVID-19. Chatter about the unknown pneumonia was spreading in Wuhans medical circles, according to one doctor and a relative of another who declined to be identified, fearing repercussions.
A scientist in China when the outbreak occurred said they heard of a Dec. 25 inspection from collaborating virologists in the country. They declined to be named out of fear of retribution.
WHO said in an email that it was not aware of the Dec. 25 investigation. It is not included in the U.N. health agencys official COVID-19 timeline.
When health officials from Beijing arrived in Wuhan on Dec. 31, they decided to disinfect the market before collecting samples, destroying critical information about the virus. Gao Fu, head of the China CDC, mentioned it to an American collaborator.
His complaint when I met him was that all the animals were gone, said Columbia University epidemiologist Ian Lipkin.
Robert Garry, who studies viruses at Tulane University, said a Dec. 25 probe would be hugely significant, given what is known about the virus and its spread.
Being able to swab it directly from the animal itself would be pretty convincing and nobody would be arguing about the origins of COVID-19, he said.
But perhaps local officials simply feared for their jobs, with memories of firings after the 2003 SARS outbreak still vivid, said Ray Yip, the founding head of the U.S. Centers for Disease Control and Prevention outpost in China.
They were trying to save their skin, hide the evidence, Yip said.
The Wuhan government did not respond to a faxed request for comment.
Another early victim was Zhang Yongzhen, the first scientist to publish a sequence of the virus. A day after he wrote a memo urging health authorities to action, Chinas top health official ordered Zhangs lab closed.
They used their official power against me and our colleagues, Zhang wrote in an email provided to AP by Edward Holmes, an Australian virologist.
On Jan. 20, 2020, a WHO delegation arrived in Wuhan for a two-day mission. China did not approve a visit to the market, but they stopped by a China CDC lab to examine infection prevention and controlprocedures, according to an internal WHO travel report. WHOs then-China representative, Dr. Gauden Galea, told colleagues in a private meeting that inquiries about COVID-19s origins went unanswered.
There are a few cadres who have performed poorly, President Xi Jinping said in unusually harsh comments in February. Some dare not take responsibility, wait timidly for orders from above, and dont move without being pushed.
The government opened investigations into top health officials, according to two former and current China CDC staff and three others familiar with the matter. Health officials were encouraged to report colleagues who mishandled the outbreak to Communist Party disciplinary bodies, according to two of the people.
Some people both inside and outside China speculated about a laboratory leak. Those suspicious included right-wing American politicians, but also researchers close to WHO.
The focus turned to the Wuhan Institute of Virology, a high-level lab that experimented with some of the worlds most dangerous viruses.
In early February 2020, some of the Wests leading scientists, headed by Dr. Jeremy Farrar, then at Britains Wellcome Trust, and Dr. Anthony Fauci, then director of the U.S. National Institutes of Health, banded together to assess the origins of the virus in calls, a Slack channel and emails.
They drafted a paper suggesting a natural evolution, but even among themselves, they could not agree on the likeliest scenario. Some were alarmed by features they thought might indicate tinkering.
There have (been) suggestions that the virus escaped from the Wuhan lab, Holmes, the Australian virologist, who believed the virus originated in nature, wrote in a Feb. 7, 2020, email. I do a lot of work in China, and I can (assure) you that a lot of people there believe they are being lied to.
American scientists close to researchers at the Wuhan Institute of Virology warned counterparts there to prepare.
James DeLuc, head of a Texas lab, emailed his Wuhan colleague on Feb. 9, 2020, saying hed already been approached by U.S. officials. Clearly addressing this will be essential, with any kind of documentation you might have, he wrote.
The Chinese government was conducting its own secret investigation into the Wuhan Institute. Gao, the head of the China CDC, and another Chinese health expert revealed its existence in interviews months and years later. Both said the investigation found no evidence of wrongdoing, which Holmes, the Australian virologist, also heard from another contact in China. But Gao said even he hadn't seen further details, and some experts suspect they may never be released.
WHO started negotiations with China for a second visit with the virus origins in mind, but it was Chinas Foreign Ministry that decided the terms.
Scientists were sidelined and politicians took control. China refused a visa for Ben Embarek, then WHOs top animal virus expert. The itinerary dropped nearly all items linked to an origins search, according to draft agendas for the trip obtained by the AP. And Gao, the China CDC head who is also a respected scientist tasked with investigating the origins, was left off the schedule.
Instead, Liang Wannian, a politician in the Communist Party hierarchy, took charge of the international delegation. Liang is an epidemiologist close to top Chinese officials and China's Foreign Ministry who is widely seen as pushing the party line, not science-backed policies, according to nine people familiar with the situation who declined to be identified to speak on a sensitive subject.
Most of the WHO delegation was not allowed to go to Wuhan, which was under lockdown. The few who did learned little. They again had no access to the Wuhan Institute of Virology or the wildlife market and obtained only scant details about China CDC efforts to trace the coronavirus there.
On the train, Liang lobbied the visiting WHO scientists to praise Chinas health response in their public report. Dr. Bruce Aylward, a senior adviser to WHO Director-General Tedros Adhanom Ghebreyesus, saw it as the best way to meet Chinas need for a strong assessment of its response.
The new section was so flattering that colleagues emailed Aylward to suggest he dial it back a bit.
It is remarkable how much knowledge about a new virus has been gained in such a short time, read the final report, which was reviewed by Chinas top health official before it went to Tedros.
As criticism of China grew, the Chinese government deflected blame. Instead of firing health officials, they declared their virus response a success and closed investigations into the officials with few job losses.
There were no real reforms, because doing reforms means admitting fault, said a public health expert in contact with Chinese health officials who asked not to be identified because of the sensitivity of the matter.
In late February 2020, the internationally respected doctor Zhong Nanshan appeared at a news conference and said that the epidemic first appeared in China, but it did not necessarily originate in China.
Chinese officials told WHO that blood tests on lab workers at the Wuhan Institute of Virology were negative, suggesting they hadnt been previously infected with bat coronaviruses. But when WHO pressed for an independent audit, Chinese officials balked and demanded WHO investigate the U.S. and other countries as well.
By the time WHO led a third visit to Wuhan in January 2021, a year into the pandemic, the atmosphere was toxic.
Liang, the Chinese health official in charge of the first two WHO visits, continued to promote the questionable theory that the virus was shipped into China on frozen food. He suppressed information suggesting it could have come from animals at the Wuhan market, organizing market workers to tell WHO experts no live wildlife was sold and cutting recent photos of wildlife at the market from the final report. There was heavy political scrutiny, with numerous Chinese officials who werent scientists or health officers present at meetings.
Despite a lack of direct access, the WHO team concluded that a lab leak was extremely unlikely. So it came as an infuriating surprise to Chinese officials when, months later, WHO chief Tedros said all origins hypotheses, including the lab leak theory, remained on the table.
China told WHO any future missions to find COVID-19 origins should be elsewhere, according to a letter obtained by AP. Since then, global cooperation on the issue has ground to a halt; an independent group convened by WHO to investigate the origins of COVID-19 in 2021 has been stymied by the lack of cooperation from China and other issues.
Chinese scientists are still under heavy pressure, according to 10 researchers and healthofficials. Researchers who published papers on the coronavirus ran into trouble with Chinese authorities. Others were barred from travel abroad for conferences and WHO meetings. Gao, the China CDC director, was investigated after U.S. President Joe Biden ordered a review of COVID-19 data, and again after giving interviews on the virus origins.
New evidence is treated with suspicion. In March 2023, scientists announced that genetic material collected from the market showed raccoon dog DNA mixed with COVID-19 in early 2020, data that WHO said should have been publicly shared years before. The findings were posted, then removed by Chinese researchers with little explanation.
The head of the China CDC Institute of Viral Disease was forced to retire over the release of the market data, according to a former China CDC official who declined to be named to speak on a sensitive topic.
It has to do with the origins, so theyre still worried, the former official said. If you try and get to the bottom of it, what if it turns out to be from China?
Other scientists note that any animal from which the virus may have originally jumped has long since disappeared.
There was a chance for China to cooperate with WHO and do some animal sampling studies that might have answered the question, said Tulane Universitys Garry. The trail to find the source has now gone cold.
Cheng reported from Geneva.
Epidemics
Influenza is still the biggest threat to global health as WHO raises fears about the spread of avian strain
Sat 20 Apr 2024 04.52 EDT
Influenza is the pathogen most likely to trigger a new pandemic in the near future, according to leading scientists.
An international survey, to be published next weekend, will reveal that 57% of senior disease experts now think that a strain of flu virus will be the cause of the next global outbreak of deadly infectious illness.
The belief that influenza is the worlds greatest pandemic threat is based on long-term research showing it is constantly evolving and mutating, said Cologne Universitys Jon Salmanton-Garca, who carried out the study.
Each winter influenza appears, he said. You could describe these outbreaks as little pandemics. They are more or less controlled because the different strains that cause them are not virulent enough but that will not necessarily be the case for ever.
Details of the survey which involved inputs from a total of 187 senior scientists will be revealed at European Society of Clinical Microbiology and Infectious Diseases (ESCMID) congress in Barcelona next weekend.
The next most likely cause of a pandemic, after influenza, is likely to be a virus dubbed Disease X that is still unknown to science, according to 21% of the experts who took part in the study. They believe the next pandemic will be caused by an as-yet-to-be-identified micro-organism that will appear out of the blue, just as the Sars-CoV-2 virus, the cause of Covid-19, did, when it started to infect humans in 2019.
Indeed, some scientists still believe Sars-CoV-2 remains a threat, with 15% of the scientists surveyed in the study rating it their most likely cause of a pandemic in the near future.
Other deadly micro-organisms such as Lassa, Nipah, Ebola and Zika viruses were rated as serious global threats by only 1% to 2% of respondents. Influenza remained by a very large degree, the number one threat in terms of its pandemic potential in the eyes of a large majority of world scientists, added Salmanton-Garca.
Last week, the World Health Organization raised fears about the alarming spread of the H5N1 strain of influenza that is causing millions of cases of avian flu across the globe. This outbreak began in 2020 and has led to the deaths or killing of tens of millions of poultry and has also wiped out millions of wild birds.
Most recently, the virus has spread to mammal species, including domestic cattle which are now infected in 12 states in the US, further increasing fears about the risks to humans. The more mammalian species the virus infects, the more opportunities it has to evolve into a strain that is dangerous to humans, Daniel Goldhill, of the Royal Veterinary College in Hatfield, told the journal Nature last week.
The appearance of the H5N1 virus in cattle was a surprise, added virologist Ed Hutchinson, of Glasgow University. Pigs can get avian flu but until recently cattle did not. They were infected with their own strains of the disease. So the appearance of H5N1 in cows was a shock.
It means that the risks of the virus getting into more and more farm animals, and then from farm animals into humans just gets higher and higher. The more the virus spreads, then the chances of it mutating so it can spread into humans goes up and up. Basically, we are rolling the dice with this virus.
To date, there has been no indication that H5N1 is spreading between humans. But in hundreds of cases where humans have been infected through contact with animals over the past 20 years, the impact has been grim. The mortality rate is extraordinarily high because humans have no natural immunity to the virus, said Jeremy Farrar, chief scientist of the World Health Organization.
The prospect of a flu pandemic is alarming, although scientists also point out that vaccines against many strains, including H5N1, have already been developed. If there was an avian flu pandemic it would still be a massive logistical challenge to produce vaccines at the scale and speed that will be needed. However, we would be much further down that road than we were with Covid-19 when a vaccine had to be developed from scratch, said Hutchinson.
Nevertheless, some lessons of preventing disease spread have been forgotten since the end of the Covid pandemic, said Salmanton-Garca. People have gone back to coughing into their hands and then shaking hands with other people. Mask-wearing has disappeared. We are going back to our old bad habits. We may come to regret that.
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In the month since federal authorities announced an outbreak of bird flu on dairy farms, they have repeatedly reassured the public that the spate of infections does not impact the nations food or milk supply, and poses little risk to the public.
Yet the outbreak among cows may be more serious than originally believed. In an obscure online update this week, the Department of Agriculture said there is now evidence that the virus is spreading among cows, and from cows to poultry.
Officials in North Carolina have detected bird flu infections in a cattle herd with no symptoms, The New York Times has learned information the U.S.D.A. has not shared publicly. The finding suggests that the infections may be more widespread than thought.
Whether there are asymptomatic animals elsewhere remains unclear, because the U.S.D.A. is not requiring farms to test cattle for infection. It has been reimbursing farmers for testing, but only for 20 cows per farm that were visibly ill. This week, the department said it would begin reimbursing farms for testing cows without symptoms.
Federal officials have shared limited genetic information about the virus with scientists and with officials in other countries, which is important for learning how the virus might be evolving as it spreads.
They are not actively monitoring infections in pigs, which are famously effective hosts for evolving flu viruses, and which are often kept in proximity to cattle. And officials have said they have no concern about the safety of milk, despite a lack of hard data.
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The H5N1 bird flu virus strain has been detected in very high concentrations in raw milk from infected animals, the WHO said Friday, though how long the virus can survive in milk is unknown.
Avian influenza A(H5N1) first emerged in 1996 but since 2020, the number of outbreaks in birds has grown exponentially, alongside an increase in the number of infected mammals.
The strain has led to the deaths of tens of millions of poultry, with wild birds and land and marine mammals also infected.
Cows and goats joined the list last montha surprising development for experts because they were not thought to be susceptible to this type of influenza.
US authorities earlier this month said a person working on a dairy farm in Texas was recovering from bird flu after being exposed to cattle.
"The case in Texas is the first case of a human infected by avian influenza by a cow," said Wenqing Zhang, head of the global influenza program at the World Health Organization.
"Bird-to-cow, cow-to-cow and cow-to-bird transmission have also been registered during these current outbreaks, which suggest that the virus may have found other routes of transition than we previously understood," she told a media briefing in Geneva.
It was only the second case of a human testing positive for bird flu in the United States, and came after the virus sickened herds that were apparently exposed to wild birds.
"Now we see multiple herds of cows affected in an increasing number of US states, which shows a further step of the virus spillover to mammals," Zhang said.
"The virus has also been detected in milk from infected animals."
Zhang said there was a "very high virus concentration in raw milk", but experts were still investigating exactly how long the virus is able to survive in milk.
The Texas health department has said the cattle infections do not present a concern for the commercial milk supply, as dairies are required to destroy milk from sick cows. Pasteurization also kills the virus.
"It is important for people to ensure safe food practices, including consuming only pasteurized milk and milk products," said Zhang.
From 2003 to April 1 this year, the WHO said it had recorded 463 deaths from 889 human cases across 23 countries, putting the case fatality rate at 52 percent.
Zhang noted that the human cases recorded in Europe and the United States in the past few yearssince the virus surgedhave been mild cases.
So far, there is no evidence that A(H5N1) is spreading between humans.
And Zhang stressed that the A(H5N1) viruses identified in cows and in the human case in Texas showed no increased adaptation to mammals.
As for potential vaccines, if required, Zhang said there were some in the pipeline.
"Having candidate vaccine viruses ready allows us to be prepared to quickly produce vaccines for humans, if this becomes necessary," she said.
"For this particular H5N1 virus detected in dairy cows, there are a couple of candidate vaccine viruses available."
In the case of a pandemic, there are close to 20 influenza vaccines licensed for pandemic use and they could be tailored with the specific virus strain in circulation, she said.
Health
By Amy Eisinger
Published April 19, 2024, 11:31 a.m. ET
A recent statement from the World Health Organization is sure to ruffle a few feathers.
The international health group expressed great concern over the rising number of bird flu cases in humans. The organization also announced Friday that the virus has been found in raw milk.
Dr. Jeremy Farrar, chief scientist at the WHO, noted that the avian flu, also called H5N1, had an extremely high mortality rate among those who had been infected around the world.
The illness remains extremely rare in the US, with just two known cases, one that occurred earlier this month and one that occurred in 2022, according to the Centers for Disease Control and Prevention. In both of those cases, the infected individuals worked in close proximity to livestock.
No human-to-human transmissions of the disease have occurred.
The great concern, of course, is that [the] virus now evolves and develops the ability to infect humans. And then critically, the ability to go from human-to-human transmission, Farrar warned.
On Friday, the WHO further warned that the virus has been found in raw milk. Officials said that drinking pasteurized milk which is the kind sold throughout the US in grocery stores is still safe. Dairy farmers in the US are also required to destroy milk from infected cows, so it should not make its way into the food supply chain in the first place.
Dr. Wenqing Zhang, who leads the WHOs global flu program, said that the virus had been identified in a very high virus concentration in raw milk from infected cows, according to the Daily Mail. Researchers are still trying to determine how long the virus might be able to survive in milk.
In general, drinking raw milk is always a bad idea, as raw milk can carry other contaminants, like salmonella, listeria and E. coli all of which can make you sick.
Zhang also reiterated the cases that have been identified in the US and in Europe have been relatively mild.
There are two types of avian flu tracked by the CDC low pathogenic and highly pathogenic. The latter, as you can probably guess, is more serious because it has a higher mortality rate in poultry, 90% 100% and often within 48 hours. The person in Texas who contracted the illness earlier this month has the highly pathogenic form of the virus.
Since January 2022, the CDC notes that over 90 million birds have been infected in 48 states. But the current outbreak isnt just affecting birds, its affecting cattle as well. Currently, eight states have avian flu cattle outbreaks.
The WHO urged US officials to monitor the situation closely because the virus could evolve into transmitting in different ways.
Do the milking structures of cows create aerosols? Is it the environment which theyre living in? Is it the transport system that is spreading this around the country? Farrar questioned. This is a huge concern and I think we have to make sure that if H5N1 did come across to humans with human-to-human transmission, that we were in a position to immediately respond with access equitably to vaccines, therapeutics and diagnostics.
This is hardly the first warning of a potential bird flu pandemic.
Earlier this month, scientists sounded the alarm that such a pandemic could be 100 times worse than COVID.
This virus [has been] on the top of the pandemic list for many, many years and probably decades, said Dr. Suresh Kuchipudi, a bird flu researcher from Pittsburgh, according to the Daily Mail.
The only hope, officials went on, is that the virus would be less deadly in humans than it is in birds.
Once its mutated to infect humans, we can only hope that the [fatality rate] drops, said John Fulton, a pharmaceutical industry consultant for vaccines, according to the Mail.
Between 2003 and 2019, 861 cases of the avian flu were identified globally and 455 people have died, meaning that the fatality rate is nearly 53%, according to the CDC.
If a pandemic were to occur, the Food and Drug Administration has a few vaccines for humans on hand, Forbes reported. Currently, theres not enough to protect all Americans, and the CDC has previously stated that it would take months and be a multi-step process to create enough in the event of a pandemic.
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In her three decades of working with elephant seals, Dr. Marcela Uhart had never seen anything like the scene on the beaches of Argentinas Valds Peninsula last October.
It was peak breeding season; the beach should have been teeming with harems of fertile females and enormous males battling one another for dominance. Instead, it was just carcass upon carcass upon carcass, recalled Dr. Uhart, who directs the Latin American wildlife health program at the University of California, Davis.
H5N1, one of the many viruses that cause bird flu, had already killed at least 24,000 South American sea lions along the continents coasts in less than a year. Now it had come for elephant seals.
Pups of all ages, from newborns to the fully weaned, lay dead or dying at the high-tide line. Sick pups lay listless, foam oozing from their mouths and noses.
Dr. Uhart called it an image from hell.
In the weeks that followed, she and a colleague protected head to toe with gloves, gowns and masks, and periodically dousing themselves with bleach carefully documented the devastation. Team members stood atop the nearby cliffs, assessing the toll with drones.
What they found was staggering: The virus had killed an estimated 17,400 seal pups, more than 95 percent of the colonys young animals.
FILE PHOTO: Brown eggs are shown in their carton in a home in Palm Springs, California, Aug. 17, 2015. Photo by Sam Mircovich/Reuters
A bird flu outbreak in U.S. dairy cows has grown to affect more than two dozen herds in eight states, just weeks after the nation's largest egg producer found the virus in its chickens.
Health officials stress that the risk to the public is low and that the U.S. food supply remains safe and stable.
READ MORE: Largest U.S. fresh egg producer detects bird flu in chickens, halts production
"At this time, there continues to be no concern that this circumstance poses a risk to consumer health, or that it affects the safety of the interstate commercial milk supply," the U.S. Food and Drug Administration said in a statement.
Here's what you need to know about bird flu and food:
As of Friday, the strain of bird flu that has killed millions of wild birds in recent years has been found in at least 26 dairy herds in eight U.S. states: Idaho, Kansas, Michigan, New Mexico, North Carolina, Ohio, Texas and South Dakota.
The virus, known as Type A H5N1, has been detected in a range of mammals over the last few years, but this is the first time it has been found in cattle, according to federal health and animal agencies. Genetic analysis of the virus does not show that it has changed to spread more easily in people, the U.S. Centers for Disease Control and Prevention said.
Agriculture officials in at least 17 states have restricted imports of dairy cattle from states where the virus has been detected, but, so far, government agencies say it's had little effect on commercial milk production. Officials believe cows likely have been infected by exposure to wild birds, but said cow-to-cow spread "cannot be ruled out."
READ MORE: Texas patient diagnosed with bird flu after contact with cows presumed to be infected
Farmers are testing cows that show symptoms of infection, including sharply reduced milk supply and lethargy. Animals that show signs or test positive for illness are being separated from other animals on the farms. The animals appear to recover within two weeks.
U.S. egg producers are watching the situation closely after bird flu was detected in chickens in Texas and Michigan. Millions of birds have been killed, but the FDA said the risk of affected eggs getting into the retail market or causing infections in humans is low because of federal inspections and other safeguards.
Scientists say there's no evidence to suggest that people can contract the virus by consuming food that's been pasteurized, or heat-treated or properly cooked.
"It's not a food safety concern," said Lee-Ann Jaykus, an emeritus food microbiologist and virologist at North Carolina State University.
Two people in U.S. have been infected with bird flu to date. A Texas dairy worker who was in close contact with an infected cow recently developed a mild eye infection and has recovered. In 2022, a prison inmate in a work program caught it while killing infected birds at a Colorado poultry farm. His only symptom was fatigue, and he recovered.
Yes, according to food safety experts and government officials.
U.S. producers are barred from selling milk from sick cows and must divert and destroy it. In addition, milk sold across state lines is required to be pasteurized, or heat-treated using a process that kills bacteria and viruses, including influenza.
READ MORE: Dairy cows in Texas, Kansas test positive for avian flu
"We firmly believe that pasteurization provides a safe milk supply," Tracey Forfa, director of the FDA's Center for Veterinary Medicine told a webinar audience this week.
The FDA and the CDC are less certain about unpasteurized, or raw, milk sold in many states, saying there's limited information about the possible transmission of the H5N1 virus in such products.
So far, no herds linked to raw milk providers have reported cows infected with bird flu, but the agencies recommend that the industry not make or sell raw milk or raw milk cheese products made with milk from cows that show symptoms or are exposed to infected cows.
U.S. health officials have long warned against the risk of foodborne illness tied to raw milk, which the CDC said caused more than 200 outbreaks that sickened more than 2,600 people between 1998 and 2018.
Still, raw milk proponents like Mark McAfee, owner of Raw Farm USA in Fresno, Calif., said the outbreak of H5N1 in commercial cows appears to have spurred higher sales of the products, despite federal warnings.
Only dairy cows, not beef cattle, have been infected or shown signs of illness to date, agriculture officials said.
The largest egg producer in the U.S. temporarily halted operations on April 2 after finding bird flu in its chickens. Cal-Maine Foods culled about 1.6 million laying hens and another 337,000 pullets, or young hens, after the detection.
The company said there was no risk to eggs in the market and that no eggs had been recalled.
Eggs that are handled properly and cooked thoroughly are safe to eat, said Barbara Kowalcyk, director of the Center for Food Safety and Nutrition Security at George Washington University.
"A lot of people like runny eggs. Personally, if I eat an egg, it's very well cooked," she said.
Still, Kowalcyk and others cautioned that the situation could change.
"This is an emerging issue and clearly this pathogen is evolving and there's a lot that we don't know," she said. "I do think that everybody is trying to figure it out as quickly as possible."
From flu to coronavirus to the ominously-named 'Disease X', epidemiologists around the world have ranked what they believe will be the most likely cause of the next global pandemic after Covid-19
Medical experts have revealed that the flu is the most likely cause of the next global pandemic, according to a new study.
The majority of infectious disease experts from around the world have ranked influenza as the top pathogen of concern in terms of its potential to spark a pandemic. Second on the list was an illness ominously dubbed 'Disease X', while others highlighted as potential causes included Coronavirus, Ebola, the original SARS virus from the early 2000s and Crimean-Congo haemorrhagic fever (CCHF).
The study, set to be formally presented at the European Society of Clinical Microbiology and Infectious Diseases' (ESCMID) Global Congress in Barcelona later this month, surveyed 187 global infectious disease experts from 57 different countries. Each expert was asked to rank various pathogens based on their perceived pandemic risk, including diseases featured in the World Health Organisation's Research and Development Blueprint for Action to Prevent Epidemics.
The experts ranked the pathogens in order of their perceived risk and also suggested additional pathogens not listed to include in their maximum of 14. Their responses revealed that influenza viruses were the top concern, with more than half (57%) ranking it first and around a sixth (17%) ranking it second. Over a fifth (21%) of the experts ranked the as-yet-unknown Disease X as having the highest pandemic potential, with another 14% ranking it second.
Coronavirus, or SARS-CoV-2, came third with nearly one in ten (8%) ranking it first and 16% ranking it second, while the original SARS-CoV virus that circulated in 2002-03 was voted number one by two per cent of respondents and second by eight per cent. The CCHF and Ebola viruses were joint fifth, with 1.6% of experts voting them first. Nipah virus, henipavirus, and Rift Valley fever virus were among the pathogens ranked lowest in terms of their perceived pandemic potential.
Dr Jon Salmanton-Garcia, the lead author of the study from the University of Cologne in Germany, explained: "The study revealed that influenza, Disease X, SARS-CoV-2, SARS-CoV, and the Ebola virus are the most worrisome pathogens concerning their pandemic potential. These pathogens are characterised by their transmissibility through respiratory droplets and a history of previous epidemic or pandemic outbreaks."
On influenza receiving the top ranking, Dr Salmanton-Garcia said the flu already causes 'mini pandemics' across the world each winter. "Each winter we have an influenza season," he said. "Yet, every season the strains involved change, that is the reason why we can get influenza several times in life and vaccines change year to year."
"In case a new strain becomes more virulent, this control could be lost." However, Dr Salmanton-Garcia added that the world is now much more prepared for a global pandemic after Covid. In the Covid-19 pandemic, we have learned many things on how to approach a respiratory virus pandemic," he continued. "This includes social distancing, hand cleaning, face masks, a renewed focus on vaccination, and trust in healthcare institutions. In parallel, institutions have also learnt a lot. Preparedness and surveillance are now, vitally, better-funded." The study was published in the journal Travel Medicine and Infectious Disease.
in the month after H5N1, bird flu spread to more humans, especially dairy cow herds, more experts in the United States are focusing more attention on the issue.
It was unexpected news last month that cows from a milking herd in Texas had tested positive for H5N1, but apparently, pasteurization of milk kills this specific virus.
Meanwhile, the World Health Organization (WHO) is expressing great concern over the increase in bird flu cases in humans, Michigan health officials are warning against raw milk, and a prominent journalist is demanding more information from USDA.
These are among the reactions that have occurred since about April 1, when a second human bird flu illness was reported in the United States.
WHO has great concern that the bird flu virus might evolve and develop an ability to infect humans.
Michigan put raw or unpasteurized milk on the foods most susceptible to the bird flu virus.
Journalist Helen Branswell, writing for STAT, raises a lot of food safety implications from bird flu, including milk, raw milk, and possible spread from chickens to cattle and even people and/or pigs.
She reports an inevitable failure in either transparency or fast-response research.
USDA claims that since the bird flu outbreak began in early 2022, the department has been practicing timely and transparent release of information.
Outside USDA, researchers are demanding the government gather samples on an ongoing basis to check for dangerous changes in the virus, but only a few genetic sequences from this outbreak have been uploaded to GISAID, the Global Initiative on Sharing All Influenza Data,
Previously, it was known as the Global Initiative on Sharing Avian Influenza Data, a global science initiative established in 2008 to provide access to GISAID, an international database widely used by scientists.
Genetic sequences are shared from early in the outbreak, which prevents outside scientists from monitoring if the virus has changed as it has moved from cow to cow or herd to herd.
USDA said it has offered outside scientists copies of a sample virus for research purposes. The department offers that USDA is analyzing other virus outbreaks, and the Centers for Disease Control and Prevention sequences will be shared in the coming days.
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The H5N1 bird flu virus strain has been detected in very high concentrations in raw milk from infected animals, the WHO said Friday, though how long the virus can survive in milk is unknown.
Avian influenza A(H5N1) first emerged in 1996 but since 2020, the number of outbreaks in birds has grown exponentially, alongside an increase in the number of infected mammals.
The strain has led to the deaths of tens of millions of poultry, with wild birds and land and marine mammals also infected.
Cows and goats joined the list last month -- a surprising development for experts because they were not thought to be susceptible to this type of influenza.
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US authorities earlier this month said a person working on a dairy farm in Texas was recovering from bird flu after being exposed to cattle.
"The case in Texas is the first case of a human infected by avian influenza by a cow," said Wenqing Zhang, head of the global influenza programme at the World Health Organization.
"Bird-to-cow, cow-to-cow and cow-to-bird transmission have also been registered during these current outbreaks, which suggest that the virus may have found other routes of transition than we previously understood," she told a media briefing in Geneva.
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It was only the second case of a human testing positive for bird flu in the United States, and came after the virus sickened herds that were apparently exposed to wild birds.
"Now we see multiple herds of cows affected in an increasing number of US states, which shows a further step of the virus spillover to mammals," Zhang said.
"The virus has also been detected in milk from infected animals."
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Zhang said there was a "very high virus concentration in raw milk", but experts were still investigating exactly how long the virus is able to survive in milk.
The Texas health department has said the cattle infections do not present a concern for the commercial milk supply, as dairies are required to destroy milk from sick cows. Pasteurisation also kills the virus.
"It is important for people to ensure safe food practices, including consuming only pasteurised milk and milk products," said Zhang.
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From 2003 to April 1 this year, the WHO said it had recorded 463 deaths from 889 human cases across 23 countries, putting the case fatality rate at 52 percent.
Zhang noted that the human cases recorded in Europe and the United States in the past few years -- since the virus surged -- have been mild cases.
So far, there is no evidence that A(H5N1) is spreading between humans.
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And Zhang stressed that the A(H5N1) viruses identified in cows and in the human case in Texas showed no increased adaptation to mammals.
As for potential vaccines, if required, Zhang said there were some in the pipeline.
"Having candidate vaccine viruses ready allows us to be prepared to quickly produce vaccines for humans, if this becomes necessary," she said.
"For this particular H5N1 virus detected in dairy cows, there are a couple of candidate vaccine viruses available."
In the case of a pandemic, there are close to 20 influenza vaccines licensed for pandemic use and they could be tailored with the specific virus strain in circulation, she said.
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