Feb 24th 2021

I was the Australian doctor on the WHO’s COVID-19 mission to China. Here’s what we found about the origins of the coronavirus

by Dominic Dwyer

 

Dominic Dwyer, Director of Public Health Pathology, NSW Health Pathology, Westmead Hospital and University of Sydney, University of Sydney

 

As I write, I am in hotel quarantine in Sydney, after returning from Wuhan, China. There, I was the Australian representative on the international World Health Organization’s (WHO) investigation into the origins of the SARS-CoV-2 virus.

Much has been said of the politics surrounding the mission to investigate the viral origins of COVID-19. So it’s easy to forget that behind these investigations are real people.

As part of the mission, we met the man who, on December 8, 2019, was the first confirmed COVID-19 case; he’s since recovered. We met the husband of a doctor who died of COVID-19 and left behind a young child. We met the doctors who worked in the Wuhan hospitals treating those early COVID-19 cases, and learned what happened to them and their colleagues. We witnessed the impact of COVID-19 on many individuals and communities, affected so early in the pandemic, when we didn’t know much about the virus, how it spreads, how to treat COVID-19, or its impacts.

We talked to our Chinese counterparts — scientists, epidemiologists, doctors — over the four weeks the WHO mission was in China. We were in meetings with them for up to 15 hours a day, so we became colleagues, even friends. This allowed us to build respect and trust in a way you couldn’t necessarily do via Zoom or email.

This is what we learned about the origins of SARS-CoV-2.

Animal origins, but not necessarily at the Wuhan markets

It was in Wuhan, in central China, that the virus, now called SARS-CoV-2, emerged in December 2019, unleashing the greatest infectious disease outbreak since the 1918-19 influenza pandemic.

Our investigations concluded the virus was most likely of animal origin. It probably crossed over to humans from bats, via an as-yet-unknown intermediary animal, at an unknown location. Such “zoonotic” diseases have triggered pandemics before. But we are still working to confirm the exact chain of events that led to the current pandemic. Sampling of bats in Hubei province and wildlife across China has revealed no SARS-CoV-2 to date.

We visited the now-closed Wuhan wet market which, in the early days of the pandemic, was blamed as the source of the virus. Some stalls at the market sold “domesticated” wildlife products. These are animals raised for food, such as bamboo rats, civets and ferret badgers. There is also evidence some domesticated wildlife may be susceptible to SARS-CoV-2. However, none of the animal products sampled after the market’s closure tested positive for SARS-CoV-2.

We also know not all of those first 174 early COVID-19 cases visited the market, including the man who was diagnosed in December 2019 with the earliest onset date.

However, when we visited the closed market, it’s easy to see how an infection might have spread there. When it was open, there would have been around 10,000 people visiting a day, in close proximity, with poor ventilation and drainage.

There’s also genetic evidence generated during the mission for a transmission cluster there. Viral sequences from several of the market cases were identical, suggesting a transmission cluster. However, there was some diversity in other viral sequences, implying other unknown or unsampled chains of transmission.

A summary of modelling studies of the time to the most recent common ancestor of SARS-CoV-2 sequences estimated the start of the pandemic between mid-November and early December. There are also publications suggesting SARS-CoV-2 circulation in various countries earlier than the first case in Wuhan, although these require confirmation.

The market in Wuhan, in the end, was more of an amplifying event rather than necessarily a true ground zero. So we need to look elsewhere for the viral origins.


Read more: Coronavirus: live animals are stressed in wet markets, and stressed animals are more likely to carry diseases


Frozen or refrigerated food not ruled out in the spread

Then there was the “cold chain” hypothesis. This is the idea the virus might have originated from elsewhere via the farming, catching, processing, transporting, refrigeration or freezing of food. Was that food ice cream, fish, wildlife meat? We don’t know. It’s unproven that this triggered the origin of the virus itself. But to what extent did it contribute to its spread? Again, we don’t know.

Several “cold chain” products present in the Wuhan market were not tested for the virus. Environmental sampling in the market showed viral surface contamination. This may indicate the introduction of SARS-CoV-2 through infected people, or contaminated animal products and “cold chain” products. Investigation of “cold chain” products and virus survival at low temperatures is still underway.


Read more: Could frozen food transmit COVID-19?


Extremely unlikely the virus escaped from a lab

The most politically sensitive option we looked at was the virus escaping from a laboratory. We concluded this was extremely unlikely.

We visited the Wuhan Institute of Virology, which is an impressive research facility, and looks to be run well, with due regard to staff health.

We spoke to the scientists there. We heard that scientists’ blood samples, which are routinely taken and stored, were tested for signs they had been infected. No evidence of antibodies to the coronavirus was found. We looked at their biosecurity audits. No evidence.

We looked at the closest virus to SARS-CoV-2 they were working on — the virus RaTG13 — which had been detected in caves in southern China where some miners had died seven years previously.

But all the scientists had was a genetic sequence for this virus. They hadn’t managed to grow it in culture. While viruses certainly do escape from laboratories, this is rare. So, we concluded it was extremely unlikely this had happened in Wuhan.


Read more: British people blame Chinese government more than their own for the spread of coronavirus


A team of investigators

When I say “we”, the mission was a joint exercise between the WHO and the Chinese health commission. In all, there were 17 Chinese and ten international experts, plus seven other experts and support staff from various agencies. We looked at the clinical epidemiology (how COVID-19 spread among people), the molecular epidemiology (the genetic makeup of the virus and its spread), and the role of animals and the environment.

The clinical epidemiology group alone looked at China’s records of 76,000 episodes from more than 200 institutions of anything that could have resembled COVID-19 — such as influenza-like illnesses, pneumonia and other respiratory illnesses. They found no clear evidence of substantial circulation of COVID-19 in Wuhan during the latter part of 2019 before the first case.

Where to now?

Our mission to China was only phase one. We are due to publish our official report in the coming weeks. Investigators will also look further afield for data, to investigate evidence the virus was circulating in Europe, for instance, earlier in 2019. Investigators will continue to test wildlife and other animals in the region for signs of the virus. And we’ll continue to learn from our experiences to improve how we investigate the next pandemic.

Irrespective of the origins of the virus, individual people with the disease are at the beginning of the epidemiology data points, sequences and numbers. The long-term physical and psychological effects — the tragedy and anxiety — will be felt in Wuhan, and elsewhere, for decades to come.


Read more: Yes, we need a global coronavirus inquiry, but not for petty political point-scoring


Dominic Dwyer, Director of Public Health Pathology, NSW Health Pathology, Westmead Hospital and University of Sydney, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Browse articles by author

More Essays

Jun 10th 2021
EXTRACT: "“The greatness of a nation and its moral progress,” Mahatma Gandhi said, “can be judged by the way its animals are treated.” If we apply that test to the world as a whole, how much moral progress have we made over the past two millennia? ...... That question is suggested by The Golden Ass, arguably the world’s earliest surviving novel, written around 170 CE, when Emperor Marcus Aurelius ruled the Roman Empire. Apuleius, the author, was an African philosopher and writer, born in what is now the Algerian city of M’Daourouch."
Jun 4th 2021
EXTRACT: "Research we’ve done, which looked at 37 adults with type 2 diabetes, found that over two weeks, prolonged sitting was associated with high blood sugar levels. But we also found that when people stood up or walked around between periods of sitting, they had lower blood sugar levels. Other studies have also had similar results."
May 28th 2021
EXTRACT: "Paul Van Doren's legacy lies in a famous company, and in his advice to young entrepreneurs to get their hands dirty, and to know what goes into making what they are selling."
May 19th 2021
EXTRACT: "May 7th marked three hundred and ten years since the philosopher David Hume was born. He is chiefly remembered as the most original and destructive of the early modern empiricists, following John Locke and George Berkeley." .... " Shocking as it may (and should) sound, Hume is implying nothing less than that the next time you turn the key in your car ignition, you are as justified to expect the engine will start as you are in believing it will turn into a pumpkin. For there is a radical contingency that pervades all our experience. We could wake up tomorrow to a world that looks and behaves very differently to the one we are in now. Matters of fact are dependent on experience and can never be known a priori — they are purely contingent, and could always turn out different than what we expect."
May 1st 2021
EXTRACT: " The sad reality is that the Mizrahim (Jews of Middle Eastern and North African descent) were discriminated against from the day of Israel’s inception, whose Ashkenazi (European Jewish) leaders viewed them as intellectually inferior, “backward,” and “too Arab,” and treated them as such, largely because the Ashkenazim agenda was to maintain their upper-class status while controlling the levers of power, which remain prevalent to this day." ..... " The greatest heartbreaking outcome is that for yet another generation of Israelis, growing up in these debilitating conditions has a direct effect on their cognitive development. A 2015 study published in Nature Neuroscience found that “family income is significantly correlated with children’s brain size…increases in income were associated with the greatest increases in brain surface area among the poorest children.” "
Apr 25th 2021
EXTRACT: "We all owe Farah Nabulsi an enormous debt of gratitude. In a short 24-minute film, The Present, she has exposed the oppressive indecency of the Israeli occupation while telling the deeply moving story of a Palestinian family. What is especially exciting is that after winning awards at a number of international film festivals​, Ms. Nabulsi has been nominated for an Academy Award for this remarkable work of art. " 
Apr 25th 2021
EXTRACT: "When I crashed to the floor of my home in Bordeaux recently after two months of Covid-19 dizziness, I was annoyed. The next day I collapsed again. Now I was worried. What I didn’t know was that my brain was sloshing around inside my skull, causing a mild concussion. Nor did I know that I was in for a whole new world of weird and wonderful hallucinations."
Apr 13th 2021
EXTRACT: "Overall, our review has found that there isn’t evidence to back up the claims that veganism is good for your heart. But that is partly because there are few studies ....... But veganism may have other health benefits. Vegans have been found to have a healthier weight and lower blood glucose levels than those who consume meat and dairy. They are also less likely to develop cancer, high blood pressure and diabetes. "
Apr 8th 2021
EXTRACT: "Pollock’s universe, the universe of Mural, cannot be said to be a rational universe. Nor is it simply devoid of all sense. It is not a purely imaginary world, although in it everything is in a constant state of flux. Mural invokes one of the oldest questions of philosophy, a question going back to the Pre-Socratic philosophers Parmenides and Heraclitus – namely, whether the nature of Reality constitutes unchanging permanence or constant movement and flux. For Pollock, the only thing that is truly unchanging is change itself. The only certainty is that all is uncertain."
Apr 8th 2021
EXTRACT: "Many present day politicians appear to have psychopathic and narcissistic traits too. It’s easy to spot such leaders, because they are always authoritarian, following hardline policies. They try to subvert democracy, to reduce the freedom of the press and clamp down on dissent. They are obsessed with national prestige, and often persecute minority groups. And they are always corrupt and lacking in moral principles."
Apr 6th 2021
EXTRACT: "This has led some to claim that not just half, but perhaps nearly all advertising money is wasted, at least online. There are similar results outside of commerce. One review of field experiments in political campaigning argued “the best estimate of the effects of campaign contact and advertising on Americans’ candidates choices in general elections is zero”. Zero!"
Mar 30th 2021
EXTRACT: "The Father is an extraordinary film, from Florian Zeller’s 2012 play entitled Le Père and directed by Zeller. I’m here to tell you why it is a ‘must see’." EDITOR'S NOTE: The official trailer is attached to the review.
Mar 28th 2021
EXTRACT: "Picasso was 26 in 1907, when he completed the Demoiselles; de Kooning was 48 in 1952, when he finished Woman I.  The difference in their ages was not an accident, for studies of hundreds of painters have revealed a striking regularity - the conceptual painters who preconceive their paintings, from Raphael to Warhol, consistently make their greatest contributions earlier in their careers than experimental painters, from Rembrandt to Pollock, who paint directly, without preparatory studies."
Mar 26th 2021
EXTRACT: "Mental toughness levels are influenced by many different factors. While genetics are partly responsible, a person’s environment is also relevant. For example, both positive experiences while you’re young and mental toughness training programmes have been found to make people mentally tougher."
Mar 20th 2021

The city of Homs has been ravaged by war, leaving millions of people homeless and

Mar 20th 2021
EXTRACT: "There are two main rival models of ethics: one is based on rights, the other on duties. The rights-based model, which traces its philosophical origins to the work of John Locke in the 17th century, starts from the assumption that individuals have rights ....... According to this approach, duties are related to rights, but only in a subordinate role. My right to health implies a duty on my country to provide some healthcare services, to the best of its abilities. This is arguably the dominant interpretation when philosophers talk about rights, including human rights." ........ "Your right to get sick, or to risk getting sick, could imply a duty on others to look after you during your illness." ..... "The pre-eminence of rights in our moral compass has vindicated unacceptable levels of selfishness. It is imperative to undertake a fundamental duty not to get sick, and to do everything in our means to avoid causing others to get sick. Morally speaking, duties should come first and should not be subordinated to rights." ..... "Putting duties before rights is not a new, revolutionary idea. In fact it is one of the oldest rules in the book of ethics. Primum non nocere, or first do no harm, is the core principle in the Hippocratic Oath historically taken by doctors, widely attributed to the ancient Greek philosopher and physician Hippocrates. It is also a fundamental principle in the moral philosophy of the Roman statesman Marcus Tullius Cicero, who in De Officiis (On Duties) argues that the first task of justice is to prevent men and women from causing harm to others."
Mar 18th 2021
EXTRACT: "Several studies have recently compared the difference between antibodies produced straight after a coronavirus infection and those that can be detected six months later. The findings have been both impressive and reassuring. Although there are fewer coronavirus-specific antibodies detectable in the blood six months after infection, the antibodies that remain have undergone significant changes. …….. the “mature” antibodies were better at recognising the variants."
Mar 15th 2021
EXTRACT: "Like Shakespeare, Goya sees evil as something existing in itself – indeed, the horror of evil arises precisely from its excess. It overflows and refuses to be contained by or integrated into our categories of reason or comprehension. By its very nature, evil refuses to remain within prescribed bounds – to remain fixed, say, within an economy where evil is counterbalanced by good. Evil is always excess of evil." ....... "Nowhere is this more evident than in war. Goya offers us a profound and sustained meditation on the nature of war ........ The image of a Napoleonic soldier gazing indifferently on a man who has been summarily hanged, probably by his own belt, expresses the tragedy of war – its dehumanization of both war’s victims and victors."
Mar 14th 2021
EXTRACT: "A blockchain company has bought a piece of Banksy artwork and burnt it. But instead of destroying the value of the art, they claim to have made it more valuable, because it was sold as a piece of blockchain art. The company behind the stunt, called Injective Protocol, bought the screen print from a New York gallery. They then live-streamed its burning on the Twitter account BurntBanksy. But why would anyone buy a piece of art just to burn it? Understanding the answer requires us to delve into the tricky world of blockchain or “NFT” art."
Mar 14th 2021
EXTRACT: "Exercise is good for your health at every age – and you can reap the benefits no matter how late in life you start. But our latest research has shown another benefit of being physically active throughout life. We found that in the US, people who were more physically active as teenagers and throughout adulthood had lower healthcare costs."