Gwynne Dyer: Millions face death threat from the past

On January 28, an 8-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. Since then, her father has died of the same flu, and her 9-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 18 people 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 then starts to pass from one person to another that the alarm bells start to ring. They are ringing now.

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 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 per cent of the world's population and killed 20 million people in four months, twice as many as died in World War I. Most of the victims were young, healthy people who died of complications such as bronchitis and pneumonia.

If a flu virus like that appeared now, could it do as much damage?

Despite the 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 such as cholera, anthrax and malaria have complex life cycles and mutate slowly, so they are easy to contain.

But if the latest version of "bird flu" is transmissible between people, we could have 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 culprit.

This was a comforting conclusion, because it meant it was a bacterial disease with a complicated life-cycle easily contained by hygiene and antibiotics, that would never come back.

But it never made sense, because the standard treatment for the Black Death, tried and tested over 300 years, was to quarantine affected families and villages for 40 days. That could not have worked if it were carried by rats, which do not respect quarantines.

Two years ago, professors Christopher Duncan and Susan Scott, of Liverpool University, suggested in their book, Biology of Plagues, that the Black Death was an Ebola-like virus, a haemorrhagic fever transmitted directly from person to person. It is frighteningly plausible.

There were two great pandemics. The first hit Europe and the Middle East in 541AD. The Roman empire had been relatively unharmed by great plagues, apart from bouts of smallpox in 170AD and measles in 250AD which killed mostly children and left survivors immune. But the new plague was different.

It returned about every 10 years for the next two centuries, and reduced the population of the Mediterranean area by between 30 and 50 per cent.

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 and 1350. It reached Europe in 1347, and killed between 30 and 40 per cent 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. Glasgow had an outbreak of bubonic plague as recently as the 1890s.

If Duncan and Scott are right, a virus is lying dormant while it tries out mutations that might break through the genetic defences that human beings evolved to defeat it last time.

When it does this, it 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, "bird flu" may be coming.

* Gwynne Dyer is a London-based independent journalist.

Herald feature: Health