The Return of the Plagues?

21 February 2003

The Return of the Plagues?

By Gwynne Dyer

On 28 January an eight-year-old girl from Hong Kong visiting relatives in southern China fell ill with influenza and was admitted to hospital. A week later she died, and since then her father has died of the same flu, while her nine-year-old brother lies gravely ill in an isolation ward in Hong Kong. The virus is outwardly similar to the A (H5N1) strain, also known as ‘bird flu’, that killed six of the eighteen people who were infected in the last outbreak in Hong Kong in 1997.

New strains of viral diseases that can kill human beings generally emerge by mutation as they hop back and forth between people and their domesticated animals. This exchange of viruses goes on all the time in farming areas — but it’s only when a lethal new virus crosses the species barrier AND THEN STARTS TO PASS FROM ONE PERSON TO ANOTHER that the alarm bells start to ring. They are ringing now.

“If this virus is transmissible from human to human then it is far more serious,” said a spokesperson for the World Health Organisation in Geneva on 19 February. The 1997 flu virus was stopped by slaughtering the 1.4 million chickens, ducks and geese in Hong Kong, but if the new one is already loose all over southern China that solution will not really work. Even the normal wave of flu that circles the world every year, slightly changed genetically each time, exacts a serious toll in lives, but once in a while something really lethal comes along. This could be one of those times.

The ‘Spanish flu’ pandemic of 1918 infected between 20 and 40 percent of the world’s population and killed 20 million people in four months, twice as many as died in the First World War — and the majority of the victims were young, healthy people who died of complications like bronchitis and pneumonia. If a flu virus like that appeared now, could it do as much damage?

Certainly the two subsequent flu pandemics, occurring after the development of anti-viral medicines, did not cause the same carnage. The impact of the 1957 ‘Asian flu’ pandemic was greatly reduced by mass vaccination: only one human being in six caught it, and it killed an estimated two million people worldwide. The 1968 ‘Hong Kong flu’ pandemic killed only a million people, and as in 1957 most of the victims were elderly. But viruses are not impressed by medical technology.

Despite the far higher standards of sanitation and medical care in the developed world, influenza death rates there have not been significantly lower than in poorer countries. Viral diseases mutate fast, antibiotics are no use against them, and good hygiene is no protection either. Bacterial diseases like cholera, anthrax and malaria have complex life cycles and mutate only slowly, so they are easy to contain — but if the latest version of ‘bird flu’ is transmissible between people, we could be looking at millions of deaths over the next year. Nor is that the worst that could happen.

The true nature of the ‘Black Death’ was long a mystery, but early in the 20th century, after doctors had found and described bubonic plague in India, experts jumped to the conclusion that a more virulent form of that disease, endemic in rats and transmitted to humans by their fleas, was the real culprit. This was a comforting conclusion, because it meant that it was a bacterial disease with a complicated life-cycle, easily contained by hygiene and antibiotics, that would never come back to trouble modern human beings.

But it never actually made sense, because the standard treatment for the Black Death, tried and tested over three hundred years, was to quarantine affected families and villages for forty days. That could not have worked if it were carried by rats, which do not respect quarantines. So two years ago professors Christopher Duncan and Susan Scott of Liverpool University suggested in their book, ‘Biology of Plagues’, that the Black Death was really an Ebola-like virus, a haemorrhagic fever transmitted directly from person to person. It is frighteningly plausible.

There were actually two Great Pandemics, and the first hit Europe and the Middle East in 541 AD. The Roman empire had been relatively unharmed by great plagues, apart from bouts of smallpox in 170 and measles in 250 which killed mostly children and left survivors immune, but the new plague was different. It returned about every ten years for the next two centuries, and reduced the population of the Mediterranean area by between 30 and 50 percent. Large parts of the Middle East and North Africa did not recover their pre-540 populations until about 100 years ago.

The plague called the Black Death appeared in Mongolia in the 1320s, and killed two-thirds of China’s population between 1330-50. It reached Europe in 1347, and killed between 30 and 40 percent of the population in the first onslaught. It returned at intervals of about a decade, with gradually diminishing lethality, until it disappeared at the end of the 17th century. The aching, the bleeding from internal organs, the red blotches on the skin caused by the effusion of blood under the skin, were all typical of Ebola-style fevers. Besides, bubonic plague, unlike the Black Death, did not disappear. There was an outbreak of bubonic plague in Glasgow as recently as the 1890s.

If Duncan and Scott are right, therefore, there is a virus out there somewhere, dormant for the moment while it tries out mutations that might break through the genetic defences that human beings evolved to defeat it last time, which could kill a significant portion of the human race in a year. The Black Death is not dead, it’s only sleeping. And in the meantime, the ‘bird flu’ may be coming.


This is a longer article of about 950 words. To shorten to 775 words, omit paragraphs 3 and 9 (“If…times”; and “There are…ago”). To shorten further to 700 words, omit also paragraph 5 (“Certainly…technology”)