Saturday, October 08, 2005
IN A RACE AGAINST TIME
Between 1347-1350, a time known as the Middle Ages, approximately 20 million people, a third to half of Western Europe's population, died in what became know as the Black Plague or Black Death.
That calamity had an enormous impact on the European economies. It created a widespread morass of dread and futility, inspired long-lasting fear and panic, and forever changed European history. It took hundreds of years for European population levels to recover.
Yet, the last century saw three separate pandemics, or worldwide epidemics.
The 1957 outbreak began in China and was a hybrid of a human and an avian, or bird, flu. Because humans had no immunity for a bird virus, the strain was particularly lethal, killing approximately 2-4 million people worldwide.
Then, in 1968, another hybrid virus emerged from China and killed about one million people around the globe.
While the latter two events paled in comparison to the Black Death of the Middle Ages, that epidemic pales in comparison to the Spanish Influenza outbreak of 1918. That particular outbreak created panic, prompting widespread quarantines.
Nonetheless, the pandemic ended up killing as many as 50 million people worldwide.
Those infected during the 1918 outbreak died very quickly, usually within two to four days of the onset of symptoms. People without symptoms could be struck suddenly and be rendered too feeble to walk within hours; many would die the next day.
That virus was closely related to the kind of influenzas that infect swine, suggesting that it entered the human population through pigs.
The Spanish Influenza is estimated to have infected up to one billion people — half the world's population at the time — and to have killed more people than any other single outbreak of disease, surpassing even the Black Death.
Now scientists around the globe are concerned about another possible pandemic. They are particularly concerned that it could be triggered by a strain of the avian flu called H5N1.
At present, H5N1 is mostly passed directly from bird to human, but health experts have warned that it is just a matter of time before it mutates into a form that is easily transmissible between people. When that happens, it could result in as many as 150 million human deaths.
So far, the virus has only killed about 60 people — mostly poultry workers — because as of now it doesn't spread easily from person to person. The fear is that H5N1 will mutate to spread easily, which would be catastrophic. Because it is so different from annual flu strains, humans have no natural immunity to it.
Whereas the global mortality rate from the 1918 outbreak was estimated at 2.5 percent–5 percent of the population, the avian bird flu presently has a 50 percent mortality rate.
World heath officials appear to be genuinely concerned.
This week President Bush commented on the worrisome potential of H5N1. Then Health and Human Services Secretary Mike Leavitt, the administration's top health official, said that "no one in the world is ready" for a potentially catastrophic outbreak of Avian bird flu. He added that U.S. officials and their counterparts around the globe recognize that a pandemic is possible and are working hard on ways to protect people from it.
Apparently the world is taking this threat seriously. More than 65 countries and international organizations participated in discussions on Thursday at the State Department about preparations for the possibility of an outbreak of bird flu.
According to a federal plan, U.S. health officials would rush overseas to wherever a bird flu outbreak occurred and work with local officials to try to contain it. If that fails, the plan calls for closing schools, restricting travel and other old-fashioned quarantine steps, depending on how fast the super-strain was spreading and the degree of its virulence.
Unfortunately, Leavitt says that state and local authorities aren't prepared to deal with the prospect of a quarantine — isolating the sick and closing large gatherings where diseases might spread.
To prepare for a potential outbreak, last month HHS began spending $100 million for the first large-scale production of a bird flu vaccine. But the department has been criticized because there isn't nearly enough of the anti-flu drug Tamiflu to treat the potential threat.
Tamiflu is the primary antiviral drug that countries around the world are now stockpiling to fend off the looming threat. Last week, the Senate passed legislation that would increase those purchases by $3 billion. Presently, U.S. health agencies have about 2 million doses of Tamiflu — enough to treat only about one percent of the population.
Leavitt cautioned that while there is a vaccine for H5N1, officials do not currently have the ability to mass produce it or get it to people quickly. Officials are concerned about a lack of ability to quickly create a vaccine to match whatever pandemic flu strain erupts.
That process currently takes months. If an outbreak were to occur, such an amount of time would be disastrous. Whereas AIDS killed 25 million in its first 25 years, the Spanish flu may have killed an equal number in just 25 weeks, beginning in September 1918.
Leavitt says the government's new plan will focus on refining vaccine production to speed the process.
There is also a real concern that as the virus mutates, the vaccines may continue to lose their effectiveness. Already a strain of the H5N1 virus is showing resistance to Tamiflu. Two reports in The Lancet medical journal this month said that resistance to anti-flu drugs was growing worldwide. In places such as China, drug resistance exceeded 70 percent.
Drug manufacturers are being urged to make more effective versions of an inhaled antiviral called Relenza, which is also known to be effective in battling the much feared H5N1.
In an effort to help them better understand and develop defenses against the threat of a future worldwide epidemic, scientists have made from scratch the Spanish flu virus that caused the 1918 worldwide outbreak. It is the first time an infectious agent behind a historic pandemic has been reconstructed.
Scientists hope their efforts will lead to effective vaccines that can thwart a global catastrophe.
Officials around the world share that hope, but many fear that they are in a race against time.