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To: Brian Sullivan who wrote (145521)	11/2/2005 3:57:52 PM
From: Brian Sullivan	Read Replies (1) \| Respond to of 793964

In predicting bird flu's course, science looks to the past By Bruce Taylor Seeman Newhouse News Service WASHINGTON — Bird flu may kill millions, or it may fizzle out among the chickens. But if it does spread among humans, the legacies of earlier flu pandemics offer at least two lessons on what to expect: • There will probably be a warning. An early "smoldering" phase of relatively few deaths might offer a grace period to get started on a vaccine or reduce large shortages of treatment drugs. • If the flu does catch fire, a large proportion of the dead will be healthy young adults, either because they don't have immunity to the flu strain or because their defense systems go into dangerous overdrive. Those likelihoods, based on recent studies of the catastrophic 1918-19 Spanish flu and two later pandemics, may figure prominently into the federal government's long-awaited blueprint to prepare for and respond to a flu calamity. President Bush today will announce his strategy on how to prepare for the next flu pandemic. Knowing a pandemic might kill large numbers of working-age adults would be vital background for health authorities deciding which Americans would get scarce supplies of flu vaccines and treatment. "The healthy, the young are critical members of society," said Shelley Hearne, executive director of Trust for America's Health, a Washington group that tracks public-health issues. "They keep the lights on, the water running, they are the first responders. These are the people needed the most in a major health crisis." In a typical flu season, the elderly account for about 90 percent of fatalities. But in a flu pandemic, "you have about half the deaths or more in people under 65," said Lone Simonsen, an epidemiologist at the National Institute of Allergy and Infectious Diseases. In 1918-19, deaths soared among the young, while mortality among the elderly didn't even suggest a severe season. Young adults' vulnerability in a pandemic may be linked to the fatal overreaction of their strong immune systems. With a serious flu, the lungs may be flooded by too many immune cells, leading to inflamed tissues, clogged air passages and cells unable to properly absorb oxygen. Or, younger people may not have immunity. Studies have shown that people who were 77 or older in 1968-69 carried effective antibodies from being exposed to a similar flu virus around 1892. "There was some benefit from having those old antibodies hanging around from childhood," Simonsen said. The U.S. has experienced three flu pandemics since 1900; all told different stories. Still, all three flus had this in common: They qualified as pandemics not because of their large death tolls, but because they were "novel" viruses — new strains unrecognized by contemporary immune systems. The two most recent pandemics — the Asian flu of 1957-58 and the Hong Kong flu of 1968-69 — shared an important characteristic: Each virus became novel through a genetic process called "reassortment." Viruses survive by entering healthy cells, hijacking their hosts to replicate before spreading. Sometimes two viruses enter the same cell. If a human virus and a bird virus meet, they might swap genes — reassort — and create a novel strain. The final product can be nasty. Hong Kong flu killed 40,000 more people in the U.S. than a routine flu. Asian flu killed 60,000 more. "The concern is, you get the virulence from the avian flu, but the contagiousness from the human strain," said Dr. James Campbell, a researcher at the Center for Vaccine Development at the University of Maryland School of Medicine. The 1918-19 Spanish flu pandemic, on the other hand, was a bird virus that mutated differently. Somehow it spread among humans without picking up human genes. That mysterious jump, along with its awesome death toll — 500,000 Americans — is why experts fear the current bird flu could be devastating. "We have no idea how many [mutations] it would take before it takes off in humans," said researcher Richard Webby, a flu specialist at St. Jude Children's Research Hospital in Memphis, Tenn. "It could be it needs to change two amino acids. It could be it needs to change 20 to 30." Health experts once assumed pandemics acted like tornadoes, arriving with almost no warning and spreading with little interruption. But recent research found early waves sometimes are mild and account for few deaths. One study of New York City showed the Spanish flu caused modest death in spring 1918 before blooming into a full-blown crisis in the fall. The 1968-69 pandemic, initially mild in many countries, caused most of its deaths in the second season. On the other hand, the 1957-58 pandemic spread aggressively in its first season. With only three pandemics to study, experts are unable to predict how the next pandemic might unfold. seattletimes.nwsource.com

To: Brian Sullivan who wrote (145521)	11/2/2005 4:08:15 PM
From: Ish	Read Replies (1) \| Respond to of 793964

<<Actually the typical fatalities from Avian Bird Flu and the 1918 virus are children, especially teenage children.>> That's similar to the Hanta Virus outbreak in the Southwest US a few years ago. The old farts survived but the healthiest people in their 20s and 30s died. In a way it's like some forms of cancer as the higher a person's metabolism is the faster it develops.

To: Brian Sullivan who wrote (145521)	11/2/2005 4:14:33 PM
From: Brian Sullivan	Read Replies (1) \| Respond to of 793964

Bird-flu victims fit few stereotypes By Margie Mason The Associated Press HANOI, Vietnam — One of the many mysteries of bird flu is that it has not infected more people like Ha Thi Quynh. The woman in her late 30s holds up a plump, live goose by its feet at Hanoi's largest poultry market. Although blood, feathers and bird droppings cling to her pants and rubber sandals, she doesn't worry about bird flu. "I have no problem," she says. Quynh has driven a motorbike loaded with about 35 chickens and geese on a two-hour trip to the market every day for the past 10 years. "If customers ask me to slaughter the chicken, then I will do it." Quynh and the others at Long Bien market say they're living proof bird flu is hard for people to catch. They work without fear or protective gear in a place where fresh blood runs through open gutters and stray feathers glide through the humid air, thick with the stench of death. They say not a single person from the market has ever gotten sick or died from the H5N1 bird-flu virus. Researchers agree. They're just not sure why these people have stayed healthy. Farmers at large poultry facilities and those who transport, sell and slaughter birds daily typically have not been infected since the virus began spreading through Asia in late 2003. Even those who slaughtered hundreds of sick birds when the virus was raging did not fall ill. It's a question that's left scientists guessing. Why has the disease attacked mostly healthy children and young adults, who may have had a few chickens pecking in their backyards or villages? Is there some sort of immunity acquired by commercial farmers and others who have worked around the poultry for so long, or is it some other reason? "The honest truth is that on a lot of answers to these questions, your guess is almost as good as mine," said Dr. Jeremy Farrar, director of Oxford University's clinical research unit at the Hospital for Tropical Diseases in Ho Chi Minh City. Farrar was part of a large research committee that reported in the New England Journal of Medicine last month what's known about those infected with bird flu. The youth of most of the virus' victims was striking. Out of 41 confirmed cases examined in the article (which doesn't include all of them) from outbreaks in 2004-05, the ages of those infected ranged from 2 to 58. In Thailand and Cambodia, researchers calculated the median age of those infected: age 14 in Thailand and 22 in Cambodia. For the Vietnam outbreak in 2004, the average age was 14. The researchers also noted that recent infections have caused "high rates of death among infants and young children. The case fatality rate was 89 percent among those younger than 15 years of age in Thailand." The paper says most victims were those who: plucked and prepared sick birds; handled and groomed fighting cocks; played with birds, including ducks that could have been infected but did not show symptoms; or ate raw duck-blood pudding or possibly undercooked meat. At least 121 people have been infected and at least 62 have died in Southeast Asia, mostly in Vietnam. Farrar said it's possible some people could have a pre-existing immunity protecting them, but there has been no research to prove that. He also said the type of contact between people and poultry could play a role. For example, a man who grooms and bandages a prize-winning fighting cock or a child who plays with a pet duck likely have relationships with birds very different from mass poultry farmers and those who slaughter the birds. Peter Horby, an epidemiologist at the World Health Organization in Hanoi, and other researchers have theorized that more children may be at risk because they're closer to the ground, crawling or walking barefoot across soil sprinkled with poultry droppings and possibly putting soiled hands or dirt into their mouths. But most of it is just guesswork. Dr. Frederick G. Hayden is a virus expert from the University of Virginia who also participated in writing the paper. He said scientists need to better understand how clusters of family members got sick, how and where the virus enters the body and why it sometimes spreads from the lungs to other organs and the central nervous system. "Clearly, this is a virus that is incredibly pathogenic in multiple species and so it really requires careful monitoring," Hayden said from Ho Chi Minh City, where he was working with health officials on a study that would help determine how to treat seasonal and bird-flu patients. He said too little is known about patients' response to antiviral medicines. Hayden said he believes a flu pandemic is coming, but there's no way of knowing when. "My sincere hope is that the virus will give us time." seattletimes.nwsource.com