Just when we seem to be easing out of the crisis, just as the death toll slows and new hospital admissions for coronavirus head towards zero, just as we begin to allow ourselves the first tentative sigh of relief, along comes a new book by an American doctor to tell us: this, folks, is just the dress rehearsal.
The real show, the plague in which half of us may well die, is yet to come.
And, if we don’t change our ways, it could be just around the corner. What we are experiencing now may feel bad enough but is, apparently, small beer.
In the ‘hurricane scale’ of epidemics, Covid- 19, with a death rate of around half of one per cent, rates a measly Category Two, possible a Three — a big blow but not catastrophic.
The Big One, the typhoon to end all typhoons, will be 100 times worse when it comes, a Category Five producing a fatality rate of one in two — a coin flip between life and death — as it gouges its way through the earth’s population of nearly eight billion people. Civilisation as we know it would cease.
What’s more, he adds ominously, ‘with pandemics explosively spreading a virus from human to human, it’s never a matter of if, but when’.
This apocalyptic warning comes from Dr Michael Greger, a scientist, medical guru and campaigning nutritionist who has long advocated the overwhelming benefits of a plant-based diet. He’s a self-confessed sweet potatoes, kale and lentils man. Meat, in all its forms, is his bete noire.
He has also done a lot of research into infectious diseases — the 3,600 footnotes and references in his mammoth 500-page book bear witness to that.
His conclusion is that our close connection to animals — keeping them, killing them, eating them — makes us vulnerable to the worst kind of epidemic. With every pork sausage, bacon sandwich and chicken nugget, we are dicing with death.
The key to all this woe awaiting us is ‘zoonoses’ — the scientific term for infections that pass from animals to humans. They cross over from them to us and overwhelm our natural immune systems, with potentially fatal consequences on an unimaginable scale.
These viruses are generally benign in the host, but mutate, adapt themselves to a different species and become lethal.
Thus tuberculosis was acquired millennia ago through goats, measles came from sheep and goats, smallpox from camels, leprosy from water buffalo, whooping cough from pigs, typhoid fever from chickens and the cold virus from cattle and horses. These zoonoses rarely get to humans directly, but via the bridge of another species.
Civets were the route for SARS to get from bats to humans; with MERS it was camels. Covid-19 originated in bats, but probably got to us by way of an infected pangolin, a rare and endangered scaly anteater whose meat is considered a delicacy in some parts of the world and whose scales are used in traditional medicines.
Once Covid-19 got a toehold, thanks to globalisation, it travelled fast and far among humans, leading to the perilous state we are in today. ‘Just one meal or medicine,’ notes Greger, ‘may end up costing humanity trillions of dollars and millions of lives’.
Which is a trifle, though, compared with what could happen next time, when the bridge the virus crosses to infect is likely to be just about the most prevalent creature on the planet — the humble chicken.
There are a mind-blowing 24 billion of them spread around the globe — getting on for double the number there were just 20 years ago.
We gulp down their cheap-as-chips meat and eggs by the ton, and turn a blind eye to the factory-farming conditions in which they are reared, force-fed with chemicals and slaughtered.
We in the West may kid ourselves into xenophobic complacency about lethal viruses, content to shrug off the blame for them getting out of hand onto cultures that lap up bat soup or pickled pangolins.
So it’s a bit of a shock to be told the greatest danger of all is lurking in our back yard.
Because if Dr Greger’s prediction is anywhere near true, the diseases harboured by chickens, notably influenza, could end up damn nearly wiping us out.
Influenza is scientists’ top pick for humanity’s next killer plague. It most famously turned deadly on a vast scale back in 1918-20, infecting at least 500 million people — a third of the world’s population at the time — and killing 10 per cent of them, possibly more.
The World Health Organisation describes it as the ‘most deadly disease event in the history of humanity’.
It killed more people in a single year than the Black Death — the bubonic plague in the Middle Ages — did in a century, and more people in 25 weeks than Aids killed in 25 years.
Death was quick but not gentle. ‘Spanish Flu’, as it misleadingly came to be known, began innocuously with a cough and aching muscles, followed by fever, before exploding into action, leaving many victims with blood squirting from their nose, ears, and eye sockets.
Purple blood blisters appeared on their skin. Froth poured from their lungs and many turned blue before suffocating. A pathologist who performed post-mortem examinations spoke of lungs six times their normal weight and so full of blood they looked ‘like melted redcurrant jelly’.
Normal flu — the type we see every year — targets the old and infirm, but the 1918 variety wiped out those in the prime of life, with mortality peaking among 20 to 34-year-olds. It stopped spreading after two years only when everyone was either dead or immune and it ran out of people to infect.
For decades, the precise starting point of humanity’s greatest killer was an unsolved puzzle, though pigs were suspected. Not until 2005 was it scientifically established that the Spanish Flu was avian influenza. Its source was birds.
This apocalyptic warning comes from Dr Michael Greger, a scientist, medical guru and campaigning nutritionist who has long advocated the overwhelming benefits of a plant-based diet
Since that mass outbreak among humans in the early part of the 20th century, bird flu has remained just that — largely confined to its host creature.
The worry is that the virus never stands still but is always mutating, and in 1997 a new strain emerged, known as H5N1, which crossed over into humans.
This is the monster lurking in the undergrowth, the one that makes epidemiologists shudder.
According to infectious disease expert Professor Michael Osterholm, it is a ‘kissing cousin of the 1918 virus’ and could lead to a repeat of 1918, but in an even more lethal way. The 1997 outbreak started with a three-year-old boy in Hong Kong, whose sore throat and tummy ache turned into a disease that curdled his blood and killed him within a week from acute respiratory and organ failure.
If it had spread, Lam Hoi-ka would have been patient zero for a new global pandemic. Fortunately, it was contained. Just 18 people contracted it, a third of whom died.
Those figures demonstrated its extreme lethality. but also that, thank goodness, it was slow to be transmitted. What worried public health scientists, however, was that the new strain turned out to be only a few mutations away from being able to replicate itself rapidly in human tissue. Here was the potential for a nightmare scenario — extreme lethality combined with ease of transmission.
One expert declared: ‘The only thing I can think of that could take a larger human death toll would be thermonuclear war.’
And where had the H5N1 in Hong Kong originated? Greger claims that in a subsequent investigation, the strongest risk factor to emerge was either direct or indirect contact with poultry. The birds in the pets corner at Lam Hoi-ka’s nursery even came under suspicion.
‘Thankfully,’ he adds, ‘H5N1 has so far remained a virus mainly of poultry, not people.’
But for how long? ‘It and other new and deadly animal viruses like it are still out there, still mutating, with an eye on the eight-billion-strong buffet of human hosts.’
And if, God forbid, it were to take hold, it would be many times worse than before. Like the 1918 version of the virus, H5N1 has a proclivity for the lungs, but it doesn’t stop there. It can go on to invade the bloodstream and ravage other internal organs until it is nothing short of a whole-body infection.