Snowy Owl
Retired in 2010, In Memoriam
AVIAN FLU: A primer
May 21, 2006. 02:40 AM
<!-- icx_story_begin -->What: A new highly pathogenic avian influenza virus, the H5N1 strain, was first observed in Hong Kong in 1997. It reappeared on a large scale in late 2003 and has spread to several Asian countries, such as Indonesia, China, Vietnam and Thailand, as well as to Europe.
How: Scientists say the main hosts for the H5N1 virus are domestic ducks and migratory waterfowl that shed the virus without falling ill. Their seasonal migration patterns are spreading H5N1 avian influenza to ever more countries.
Impact: Experts say there is a great likelihood of H5N1 avian influenza virus evolving into a humanly transmissible form. What remains uncertain is when and how virulent the "human H5N1" virus will be.
Compared to SARS: A potential human H5N1 virus would have several key differences to the coronavirus that caused SARS:
1. Influenza viruses are airborne, easily transmitted by a cough or a sneeze; SARS was droplet-borne: only close face-to-face contact transmitted SARS.
2. People infected by influenza viruses are infectious before they are sick. This means the basic measures that helped control SARS, such as fever-checks, airport screening and isolating sick people, would be of little or no use against a possible human H5N1 virus.
3. SARS's incubation period is 10 days, giving time to trace contacts and quarantine suspects. Influenza has a 2- to 3-day incubation period, so these measures would be useless.
4. H5NI could potentially spread to all five continents within weeks. Once SARS became virulent in early 2003, it spread from South China to Hong Kong, Vietnam and Canada within three weeks.
Online resources:
World Health Organization: http://www.who.int/csr/disease/ avian_influenza/en.
International Society for Infectious Diseases: http://www.promed mail.org.
U.S. Center for Disease Control and Prevention: http://www.cdc .gov/flu/avian/index.htm.
U.S. government: http://www.pan demicflu.govSource: Citigroup
http://www.thestar.com
May 21, 2006. 02:40 AM
<!-- icx_story_begin -->What: A new highly pathogenic avian influenza virus, the H5N1 strain, was first observed in Hong Kong in 1997. It reappeared on a large scale in late 2003 and has spread to several Asian countries, such as Indonesia, China, Vietnam and Thailand, as well as to Europe.
How: Scientists say the main hosts for the H5N1 virus are domestic ducks and migratory waterfowl that shed the virus without falling ill. Their seasonal migration patterns are spreading H5N1 avian influenza to ever more countries.
Impact: Experts say there is a great likelihood of H5N1 avian influenza virus evolving into a humanly transmissible form. What remains uncertain is when and how virulent the "human H5N1" virus will be.
Compared to SARS: A potential human H5N1 virus would have several key differences to the coronavirus that caused SARS:
1. Influenza viruses are airborne, easily transmitted by a cough or a sneeze; SARS was droplet-borne: only close face-to-face contact transmitted SARS.
2. People infected by influenza viruses are infectious before they are sick. This means the basic measures that helped control SARS, such as fever-checks, airport screening and isolating sick people, would be of little or no use against a possible human H5N1 virus.
3. SARS's incubation period is 10 days, giving time to trace contacts and quarantine suspects. Influenza has a 2- to 3-day incubation period, so these measures would be useless.
4. H5NI could potentially spread to all five continents within weeks. Once SARS became virulent in early 2003, it spread from South China to Hong Kong, Vietnam and Canada within three weeks.
Online resources:
World Health Organization: http://www.who.int/csr/disease/ avian_influenza/en.
International Society for Infectious Diseases: http://www.promed mail.org.
U.S. Center for Disease Control and Prevention: http://www.cdc .gov/flu/avian/index.htm.
U.S. government: http://www.pan demicflu.govSource: Citigroup
http://www.thestar.com