world 'due for a new pandemic'

World 'due for a new pandemic'
13/02/2006
The bird-flu virus outbreak was in line with historical precedent which showed the world was due for another pandemic, said the National Institute for Communicable Diseases on Monday.

"We are due for one (a pandemic)... if the periodicity holds," said the institute's director, Professor Barry Schoub in Johannesburg.

Since the 12th century, pandemics have occurred at a rate of about two or three every 100 years, he said.

The last pandemic was the Hong Kong flu of 1968 to 1969.

"It's a probability, but not a certainty," he said of the likelihood of the H5N1 virus spreading between humans.

The second cause for concern, Schoub said, was that the virus was established in the bird population and was a threat to humans.

For the H5N1 virus to cause the next pandemic, three factors were needed. The first two - the presence of the virus and for it to cross the species barrier - were already present.

Similarities with deadly Spanish flu

The third factor was efficient human-to-human transmission.

Schoub said there was little evidence of efficient transmission between humans.

A worrying factor, however, was that there were many "molecular similarities" between the virulent H5N1 virus and that which caused the Spanish influenza of 1918 to 1919.

This killed an estimated 40 million people worldwide.

Schoub said the fact that the virus, first detected in Hong Kong in 1997, had still not spread between humans was cause for hope.

"It has had the opportunity, but has not grasped it," he said.

The H5N1 virus has so far killed 88 - mainly young - people out of 166 infected in seven, mostly east Asian, countries.

"There is now preliminary evidence of some resistance to (anti-viral drug) Tamiflu, but it's still an effective drug," Schoub said.

The World Health Organisation had stockpiled five million doses of the drug.

So many unpredictables

International travel would help to spread a pandemic very quickly.

The Spanish influenza took between five and six months to spread, in an era when global travel was not yet common.

"No country in the world is really fully prepared for a global pandemic. It's very difficult because there are so many unpredictables."

It was also difficult to screen people at airports because the virus could be in incubation.

The recent discovery of the virus in Nigeria was cause for concern, said Schoub.