Killer Flu Virus Changes Its Skin

It happened three times in the last century -- and nearly happened again in 1997. Now experts say that another killer flu epidemic is brewing.

Will it emerge to kill millions -- as did the 1918 Spanish flu? Or will it be nipped in the bud, as in the 1997 emergence of chicken flu in humans? There are no easy answers. But now the same experts who led the successful effort to stop the 1997 virus in Hong Kong raise troubling new questions.

Those questions come from a report in the June 25 issue of the prestigious Proceedings of the National Academy of Sciences. The report shows that flu viruses similar to the killer 1997 strain reappeared in Hong Kong in 2001. It happened again this year, the authors now say.

"We don't want this in humans or the world will be in deep, deep trouble," researcher Robert G. Webster, PhD, tells WebMD. "What will you do if one of these gets away? You haven't got anything to do. Are we going to be prepared for this? It is going to happen sooner or later, and authorities are not stockpiling effective drugs. We have had two years of very mild flu, and now these drugs are in very short supply. If one of these viruses gets away, we are in for trouble."

And while none of the 2001 or 2002 viruses infected humans, they had acquired dangerous new genes. Lab mice exposed to some of these viruses quickly developed brain infections and died. Webster is director of the World Health Organization collaborating center on influenza viruses in lower animals and birds.

Flu viruses can change their genes to become more infectious and more deadly to humans. The new study shows that the potentially deadly Hong Kong flu virus known as H5N1 has been shifting in alarming ways.

"This time, this virus has picked up a whole set of new internal genes," Webster says. "What worries me is this shows it is possible for this virus to 'mate' with a number of different viruses and produce viruses highly [lethal] for poultry. The key question is, 'What is the potential in humans?' Can you afford to let the experiment happen? The worrying thing is that all these original viruses continue to circulate. If this virus mates with a virus that allows it to spread from human to human, it would be of great worry to me."

David L. Suarez, DVM, PhD, is lead scientist for avian influenza at the U.S. Department of Agriculture's Southeast Poultry Research Laboratory in Athens, Ga. He's the point man for U.S. efforts to track emerging flu epidemics in poultry.

"There is danger of human infection -- the risk is not zero," Suarez tells WebMD. "The major concern is that the genes that made up the 1997 outbreak are still circulating. Fortunately, we haven't seen a virus with the same set of genes as in 1997, but the fear is that we could always see something like that."

Another author of the PNAS study is J.S. Malik Peiris, MD, PhD, professor of microbiology at the University of Hong Kong. Peiris points out that none of the H5N1 viruses seen since 1997 had the right gene combination to let them infect humans.

But Peiris also says that we should not be concentrating solely on the H5N1 viruses as a possible cause of a global flu epidemic. A number of other influenza viruses -- some more widespread than H5N1 -- also deserve close attention, he says.

In 1997, Hong Kong authorities had all of the city's 3 million chickens slaughtered. While there were 18 human infections and eight deaths, all of these infections came directly from birds. Killing the poultry stopped the outbreak before the virus could learn to spread from human to human. It was a close call -- and the first time a human action prevented a worldwide epidemic.

In 2001, Hong Kong authorities again ordered the deaths of hundreds of thousands of chickens. They also established strict new rules for the area's poultry farmers and live-poultry markets. Affected chickens were killed this year, too, but a new poultry vaccine was used to prevent spread among uninfected birds. Unfortunately, no such safeguards are in place in mainland China.

Mainland China is still denying they have a problem, Saurez says. "For me it is a very big concern." Every year since 1997 we have seen flu viruses that cause severe disease -- the source for which was China, he says. "It is there. So obviously they are unable or unwilling to control it. It is a huge risk."

The 1918 flu virus killed 675,000 Americans and more than 20 million people around the world. The just-fought World War had cost 9 million casualties.

The virus spread like wildfire and killed its victims by causing fluid buildup in the lungs - pulmonary edema - or by compromising the immune system so bacterial pneumonia developed.

I had an ancestor in Fort Collins CO who went to work healthy, felt sick at noon, asked to leave early, then went home and died that very evening.

Now imagine a flu virus is on the loose. It has mutated so its effect on humans is severe to fatal. A person on vacation or business visits the locale, and contracts the virus. He flies home that day, infecting all who he breathes on or touches. He interacts with family members. They now have the virus. He goes to work the next day. He attributes his headache and lack of energy to jet lag. He gets through the day, and goes home feeling drained. He self-medicates with alcoholic beverages and so fails to realize he's getting sicker.

The next morning his wife finds him collapsed in the bathroom. Over his mumbled protests she calls the hospital. He's admitted and tests are done. The results have everyone scratching their heads. Someone thinks to ask where the man has traveled lately. A tropical disease specialist is called in. Various noxious diseases are ruled out. Then man is very ill indeed now. He has fluid in his lungs. At last someone compares him with flu victims from medical journals. He's rushed to an isolation ward and the Center for Disease Control is notified. All the while everyone is spreading the infection.

New flu victims start to trickle into hospitals in the area, and in some far-flung locales. The trickle becomes a flood in 2 days. The man who brought the flu home succumbs to pulmonary edema. He is the first victim. Will there be hundreds more?
Thousands?
Millions?

Have you ever noticed how there has never been an outbreak of the "Cleveland flu" or the "Denver flu", but there's always some new strain of flu floating in from China, every year, like clockwork? The cause is the appallingly poor sanitation in the rural areas of China, and the very close proximity of the humans to pigs and ducks, including their traditional practice of feeding raw human waste to pigs. The result is a new flu every year, something new to cause people to get sick and die all over the world.

It sure would be nice if the government of China could maybe spend a little less on missiles and bombs and airplanes and nuclear weapons and maybe spend a little more on plumbing and sanitation and toilets and hygene classes for the masses. Just a thought. Might spare us all a major epidemic.

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