Stories tagged avian influenza

Oct
10
2005

It's in the news. People are dying from a relative of the 1918 Influenza virus half a world away, and scientists fear it may be the next pandemic. Sounds like science fiction, or the latest box-office smash, right? Unfortunately, it's real, and is happening right now.

chickens: (Photo courtesy Laura Hadden)
chickens: (Photo courtesy Laura Hadden)

In Southeast Asia, a virus known as avian influenza or avian flu has the potential to spread and kill humans with terrifying speed. Avian flu is also known as H5N1 for the proteins that bind, infect, and destroy its host cell to thrive. Chickens can die within hours of exposure, swollen and hemorrhaging, but it is just as lethal to mammals from lab mice to tigers. The virus has decimated bird flocks in 11 countries mostly in Asia, and has killed 62 people (half the known cases) to date, with highest fatalities occurring in Vietnam, Cambodia, and Thailand. So far, nearly all people infected contracted the sickness directly from infected poultry and at this point there is no confirmed evidence of efficient human-to-human transmission. However, health authorities fear that the H5N1 strain will likely mutate into a pathogen easily passed between humans if it continues to persist in the environment. If that happens, and authorities believe it's only a matter of time, the world could face a catastrophic pandemic.

Many health organizations and governments are stockpiling a drug (Tamiflu) to protect against this potential pandemic, but scientists are reporting that a strain of H5N1 avian flu virus is showing resistance to the antiviral drug. Scientists are working to avoid this disaster by detecting changes in the evolving H5N1 virus. As a first step, scientists have rebuilt the 1918 flu-a disease that killed as many as 50 million people-from pieces of genetic material retrieved from the lungs of people who died 87 years ago. Gene-swapping experiments are starting to give scientists some clues in the lab. When small substitutions were made, the reconstructed virus could no longer replicate in the lungs of mice, kill animals, or attach itself to human lung cells.

So far H5N1 has not yet learned the trick of racing from person to person like the ordinary flu and maybe never will. Nevertheless, experts fear that the risk could materialize and are urging the world to prepare for the worst.

United Nations Food and Agriculture Program

NPR Health and Science Report

Jun
10
2005

The Avian Flu, or bird flu, is an infection caused by influenza viruses in birds. Wild birds worldwide carry influenza viruses but do not usually become sick from them. However, the same influenza virus that does not make wild birds sick can make some domesticated birds, such as chickens and turkeys, very sick and can kill them.

Scientists are closely monitoring an outbreak of avian flu in Asia. Avian flu has been found in birds in Cambodia, China, Hong Kong, Indonesia, Japan, Laos, Pakistan, South Korea, Thailand, and Vietnam. Human cases of avian influenza have been reported in Thailand and Vietnam, some of which have lead to deaths.

Organizations such as the World Health Organization and the Center for Disease Control are worried that the avian flu will become the next pandemic — an outbreak of an infectious disease that affects people over a large geographic area.

An influenza pandemic occurs when a new influenza virus emerges in people, causes serious illness, and then spreads easily from person to person worldwide. This is different from seasonal outbreaks of influenza. Seasonal outbreaks are caused by influenza viruses that are already in existence among people, where pandemic outbreaks are caused by new subtypes or by subtypes that have never circulated among people. Past influenza pandemics have been extremely costly. For example, from 1918 — 1919 the "Spanish flu" pandemic caused the deaths of more than 500,000 people in the U.S.

Many scientists and researchers believe it is just a matter of time until the next influenza pandemic. It is unlikely that a vaccine would be available in the early stages of the pandemic, and once a vaccine is developed it takes several months before it becomes widely available.

In order to be as prepared as possible for an influenza pandemic, the US Department of Health and Human Services has developed a Pandemic Influenza Response and Preparedness Plan. To view the plan, and to learn more about the avian flu, visit the US Department of Health and Human Service's web site.