We worry about the Ebola virus and rabies. These rare diseases make sensational headlines. But 40,000 people per year are killed by influenza in the US alone and we ignore it. To most of us, flu means little more than a bad cold. In reality, influenza is one of the deadliest diseases known to man, which can kill within two days of infection. All you need to do to be infected is to breathe. In the pandemic in 1918, influenza killed an estimated 40 million people worldwide, causing internal bleeding and turning their lungs into red jelly. Everyone who lived through it knew someone who didn't. Known as "the Spanish Lady", the plague was wrongly believed to have originated in Spain. In fact, it began in pigs in the US in the spring of 1918. Its preferred target was healthy, young adults and it spread to Europe on overcrowded first World War troop carriers, then circumnavigated the globe within a matter of months. Today, thanks to air travel, the next pandemic will spread within days.
There is no question that it will happen. "The odds in my mind are 100 per cent that we will have a pandemic in the future . . . we know it's possible because it happened once," says Dr Jeffrey Taubenberger, a military molecular pathologist in the US who is obsessed with cracking the genetic code of the 1918 virus. He has managed to genetically analyse tissue samples of the epidemic's victims and, in a sensational breakthrough which was published in Science in 1997, revealed that the virus originated in pigs and that it was completely unique to anything seen before.
The next vicious influenza pandemic will kill at least 100 million people worldwide - one in 60 of all people on the earth, estimates Pete Davies, author of a new book on the 1918 pandemic, Catching Cold. The devastation will be unthinkable because we are not prepared for it. We are no more able to treat influenza at the end of the 20th century than we were at the beginning. The Cambridge World History of Human Disease has a description of influenza which is the equivalent of a mass death sentence: "There is no specific cure that is effective against this viral disease".
It is salutary to remember what happened in 1918. Entire communities in Ireland and the rest of the world were devastated as the virus arrived on trains and mail-boats. Hundreds of people would be stricken within days of the arrival of one infected person. Contemporary accounts throughout the Western world tell of a nightmare situation, in which children died in their parents' arms and parents died where they stood. There was no room in hospitals, morgues were packed, there were endless funerals and the bereaved were forced to dig graves for their own dead. In Alaska, Inuit children were found huddled around the bodies of their parents, already being eaten by their wolfish dogs. In Wales, a doctor commented that he had buried more young mothers in the previous five weeks than he had in the previous 10 years.
In the US, where 550,000 were killed - about 10 times the battle deaths of Americans in the first World War - people tied cucumbers to their ankles in a vain attempt to avoid infection. In Ireland, doctors treated the epidemic with calomel, oxygen, stimulants, salicylates and even strychnine, but the truth was that the only treatment was rest and hope. Between October 1918 and March 1919, 18,376 people died on the island of Ireland. As in the rest of the world, two-thirds of the Irish victims were young: between 15 and 45 years of age, or else younger than five years old. Newborns didn't stand a chance.
"Since the period of the Great Famine (`the Black Forty-seven'), with its awful attendant horrors of fever and cholera, no disease of an epidemic nature created so much havoc in any one year in Ireland as influenza in 1918," wrote Sir William J. Thompson, MD, registrar-general, in Mortality from Influenza in Ireland, published in 1920.
More people died of influenza in 1918 than in the previous 20 years' epidemics combined - including enteric fever, typhus, smallpox, measles, scarlet fever, whooping cough and diptheria, as well as influenza.
The Plague was worst in Co Dublin, where the death rate was 406 per 100,000, among the highest in the world, due perhaps to the concentration of workhouses and fever sheds in the capital. The Dublin City Report upon the State of Public Health, 1919, records that in the 30 days from October to November 1918, the death rate doubled to 50 people per 1,000. In other words, one in 20 people died - at least half of them from influenza and many more from influenza-related pneumonia. The records of medical personnel give us an idea of what we could be up against when the next pandemic strikes. The 1918 virus turned human lungs into bloody, spongy, Swiss cheese when attacked by an especially nasty strain of influenza. Thompson, conducting autopsies in Dublin in 1918, noted that the influenza virus filled lungs with stinking sputum and could also wreck the spleen, kidneys, heart and liver. Dr Hubert French, a British doctor who treated patients in both civilian and military hospitals in 1918, gave a dramatic account. "The patient would be seized rapidly, or almost suddenly, with a sense of such prostration as to be utterly unable to carry on with what he might be doing; from sheer lassitude he would be obliged to lie down where he was, or crawl with difficulty back to bed."
Hospitals filled as temperatures rocketed up to 104 degrees. Patients had coated tongues, flushed faces, drooping eyelids and hawking coughs. People grew so sore that they could not move or speak as frothy liquids welled up in their throats. Nosebleeds could be so heavy as to soak the sheets. Those who survived got better within a few days. Those who did not, moved on to the fatal stage.
The deadliest symptom, writes Davies, was heliotrope cyanosis. "Starved of oxygen, the victim's lips and ears would turn purple or blue, while the rest of his skin first flushed, then turned pale white or grey, the colour of wet ashes. This would herald widespread haemorrhages, with blood-soaked swellings in the intercellular tissue, and the coughing and spitting up of enormous quantities of purulent sputum."
This mass murder was made possible by the virus's secret weapons, hemagglutinin spikes which catch hold of the host cell, allowing the virus to insert its genetic material. Once inside the host cell, the virus dismembers it and uses the material from it to replicate itself. These new viruses are released as the host disintegrates, and head off to attack more cells in their turn.
"In essence," writes Davies, "it's a destructive form of molecular burglary; flu gets into the building, cracks the safe, takes what it wants, and wrecks the place on the way out. Moreover, the chemical intricacy of the process by which it breaks in is dazzlingly ingenious. It had to be because the genome, the heart of the virus, is extremely vulnerable; left out on its own, this genetic material would fall prey to marauding enzymes and be chopped to bits in no time. The genome is therefore secured inside a lipid, spherical envelope, on whose surface the hemagglutinin stands ready to tie up the victim."
It is indeed ironic that at the end of a century in which we travelled to the moon, we are held hostage by something we cannot see without a microscope. We have antibiotics to treat secondary lung infections associated with flu, but overuse of antibiotics has resulted in many of the bacteria which cause pneumonia becoming antibiotic-resistant killers. There are one or two anti-viral drugs which may be effective against an especially vicious virus, but supply is so limited that in the event of an epidemic, use would probably be limited to medical staff and essential government and army personnel. We have vaccines against the influenza viruses we know, but each new influenza is different. A virus is like a terrorist, moving swiftly and always changing disguises. Each year, experts from the World Health Organisation and the Centres for Disease Control in Atlanta, Georgia, get together to decide which known flu virus is most likely to be deadly, and which vaccine to manufacture. Our own Department of Health follows their advice and provides the vaccine for the elderly, the immune-compromised and babies.
But the unsettling fact is that a new virus will one day emerge that WHO and the CDC are not prepared for, as the CDC knows only too well. Through a process known as "antigenic drift", viruses can change so dramatically as to be completely unrecognisable to our immune systems and to known vaccines. We can always make a new vaccine, but this can take six months, by which time 100 million lives could be lost.
You would think that such a sinister timebomb as an imminent flu pandemic would be receiving generous intergovernmental funding and a well-organised international research campaign. Instead, the effort to understand flu is disorganised and inefficient, run by a small clique of determined, competitive and, at times, eccentric scientists all determined to be the first to make the breakthrough. If world governments were serious about preventing the next epidemic, they wouldn't be leaving the matter to the ambitions of a handful of scientists, Davies argues.
Mankind had a narrow escape in 1993 in Philadelphia, and again in late 1997 in Hong Kong, when a pathogenic strain of influenza was turning chickens into "bloody Jell-O", in the words of one observer. The virus passed from chickens to kill six people, among them a three-year-old boy. Worldwide plague was avoided when every chicken in Hong Kong was slaughtered. But Hong Kong is a sophisticated, well-organised city. We have no idea what's happening in China for example, where people farm and live in close quarters with domesticated fowl and pigs and where viruses are persistently mutating. If such a virus moves to the human population undetected, what we will be able to do will be too little, too late.
Davies warns: "This tiny packet of molecules, so tiny that a million of them can fit on a pinhead and leave room to spare, contains in its shape-shifting genes an awesome power. Somewhere in the world, it's killing someone even as you're reading this." And the flu season doesn't even start until September.
Catching Cold by Pete Davies (published by Michael Joseph, £12.99 in the UK)