Web Zap*Germs Archive

March 28, 2006

UN's Dr. Nabarro on Avian Flu

Today's NYT has a profile of Dr David Nabarro, the United Nations' chief avian flu coordinator. After focusing on how scared Dr. Nabarro is of the potential impact of H5N1 bird flu, the scribber gets down to specifics, of which the quotes below are a sample.

I especially like his point about the sudden spread of the virus, after years of "smoldering" in Asia. He attributes it to migratory birds. But those birds migrate every year, and it wasn't till last year that they apparently picked up the disease and took it with them to new regions. Why that delay? And, what about the role of bird smuggling as a vector? Not much talk is being made of that.
The infection of millions more birds in many more countries "has led to an exponential increase of the load of virus in the world," he said. And influenza is a fast-mutating virus. Each infected bird and person is actually awash in minutely different strains, and it takes lengthy genetic testing to sequence each one — so if a pandemic strain were to appear, "it might be quite difficult for us to pick up that change when it happens."

To skeptics who doubt that the A(H5N1) strain will become a threat to humans because it has existed for 10 years without doing so, he counters that it had the same 10 years to move out of Southeast Asia but did not until last year, when it shot across half the globe.

The skepticism reminds him of his stint in East Africa in the 1980's. No one realized then how widespread the AIDS virus was, and it was still unclear whether it was transmitted by sex. Some experts argued that sex was such an inefficient method of disease transmission that it would never be much of a threat. It has now killed 20 million people, and 40 million more are infected.

"We failed to give it the proper focus, right at the beginning," he said.

Like early AIDS, he said, avian flu has too many unanswered questions, like: Why did the disease, after years of smoldering in poultry, suddenly start hitchhiking in migratory birds? Why does the northern China strain — the one now spreading westward — turn up so many false negatives in diagnostic tests? Why did so many people fall sick so quickly in Turkey?

"Bits of the puzzle are missing," he said. "In six months, will we be cursing ourselves for missing some key phenomena now?"

He fears that the virus will soon be endemic in birds everywhere, rendering containment fruitless and condemning the world to mounting a perpetual vigil for human outbreaks. Its movement into cats frightens him even more because humans routinely curl up with them.


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