Pandemics: Tomorrow

"Pandemic" strikes fear in people who know what the word means, and health experts say it's lurking somewhere in the future — possibly very soon.

A deadly avian flu affecting poultry in eight Asian countries this year has already been transmitted to some humans. If it starts spreading person to person, it could be devastating, health experts warn.

Any flu outbreak is called an epidemic. A pandemic occurs when a new form of influenza or an old one against which people have no antibodies breaks out. Past pandemics have killed thousands and even millions.

A World Health Organization bulletin contains a sober warning: "WHO believes the appearance of H5N1, which is now widely entrenched in Asia, signals that the world has moved closer to the next pandemic. While it is impossible to accurately forecast the magnitude of the next pandemic, we do know that much of the world is unprepared for a pandemic of any size."

"It's hard to quantify the risk" of pandemic, said Dr. Patrick Luedtke, state deputy epidemiologist. "A pandemic will probably happen at some point. Will it be our lifetime or our children's? We don't know. . . . It will be how we respond to it that matters most."

"It's just the nature of the virus," said Salt Lake Valley Health Department epidemiologist Ilene Risk. "Influenza Type A has the ability to rapidly change and cause more severe disease, so it could happen."

Worldwide, health experts are gearing up in case the current Asian outbreak of avian flu starts spreading from person to person. Avian flu has killed 45 people so far, all of whom contracted it from birds. Testing is about to begin on an experimental vaccine, disease surveillance is moving into high gear and the U.S. government is stockpiling anti-viral drugs and vaccine.

The next pandemic

The World Health Organization has estimated that the next pandemic is likely to kill between 2 million and 50 million people. Because a pandemic is typically caused by a new form of virus, its real magnitude can't be predicted.

The mechanics of a pandemic seem deceptively simple.

Influenza A viruses all have two proteins on their surface, hemagglutinin and neuraminidase (the "H" and "N" health experts use to show which flu strain is going around). There are many subtypes of each — 15 H's and nine N's — that can combine in various ways to create a different virus. Not all attack humans.