Researchers unlock secrets of 1918 flu pandemic

[Guest guest]

Love the part where it says: "They mixed samples of the 1918

influenza strain with modern seasonal flu viruses to find the three

genes and said their study might help in the development of new flu

drugs."Gee that sounds safe. But I'm sure we can trust the scientists!

Researchers unlock secrets of 1918 flu pandemic57 mins agoWASHINGTON

(Reuters) – Researchers have found out what made the 1918 flu pandemic

so deadly -- a group of three genes that lets the virus invade the

lungs and cause pneumonia.They mixed samples of the 1918

influenza strain with modern seasonal flu viruses to find the three

genes and said their study might help in the development of new flu

drugs.The discovery, published in Tuesday's issue of the

Proceedings of the National Academy of Sciences, could also point to

mutations that might turn ordinary flu into a dangerous pandemic strain.Yoshihiro

Kawaoka of the University of Wisconsin and colleagues at the

Universities of Kobe and Tokyo in Japan used ferrets, which develop flu

in ways very similar to humans.Usually flu causes an upper

respiratory infection affecting the nose and throat, as well as

so-called systemic illness causing fever, muscle aches and weakness.But

some people become seriously ill and develop pneumonia. Sometimes

bacteria cause the pneumonia and sometimes flu does it directly.During pandemics, such as in 1918, a new and more dangerous flu strain emerges."The

1918 influenza pandemic was the most devastating outbreak of infectious

disease in human history, accounting for about 50 million deaths

worldwide," Kawaoka's team wrote.It killed 2.5 percent of

victims, compared to fewer than 1 percent during most annual flu

epidemics. Autopsies showed many of the victims, often otherwise

healthy young adults, died of severe pneumonia."We wanted to know why the 1918 flu caused severe pneumonia," Kawaoka said in a statement.They

painstakingly substituted single genes from the 1918 virus into modern

flu viruses and, one after another, they acted like garden-variety flu,

infecting only the upper respiratory tract.But a complex of three genes helped to make the virus live and reproduce deep in the lungs.The

three genes -- called PA, PB1, and PB2 -- along with a 1918 version of

the nucleoprotein or NP gene, made modern seasonal flu kill ferrets in

much the same way as the original 1918 flu, Kawaoka's team found.Most

flu experts agree that a pandemic of influenza will almost certainly

strike again. No one knows when or what strain it will be but one big

suspect now is the H5N1 avian influenza virus.H5N1 is

circulating among poultry in Asia, Europe and parts of Africa. It

rarely affects humans but has killed 247 of the 391 people infected

since 2003.A few mutations would make it into a pandemic strain that could kill millions globally within a few months.Four

licensed drugs can fight flu but the viruses regularly mutate into

resistant forms -- just as bacteria evolve into forms that evade

antibiotics.(Reporting by Maggie Fox, editing by Will Dunham and O'Callaghan)http://news.yahoo.com/s/nm/20081229/sc_nm/us_flu1918The discovery, published in Tuesday's issue of the

Proceedings of the National Academy of Sciences, could also point to

mutations that might turn ordinary flu into a dangerous pandemic strain.Yoshihiro

Kawaoka of the University of Wisconsin and colleagues at the

Universities of Kobe and Tokyo in Japan used ferrets, which develop flu

in ways very similar to humans.Usually flu causes an upper

respiratory infection affecting the nose and throat, as well as

so-called systemic illness causing fever, muscle aches and weakness.But

some people become seriously ill and develop pneumonia. Sometimes

bacteria cause the pneumonia and sometimes flu does it directly.During pandemics, such as in 1918, a new and more dangerous flu strain emerges."The

1918 influenza pandemic was the most devastating outbreak of infectious

disease in human history, accounting for about 50 million deaths

worldwide," Kawaoka's team wrote.It killed 2.5 percent of

victims, compared to fewer than 1 percent during most annual flu

epidemics. Autopsies showed many of the victims, often otherwise

healthy young adults, died of severe pneumonia."We wanted to know why the 1918 flu caused severe pneumonia," Kawaoka said in a statement.They

painstakingly substituted single genes from the 1918 virus into modern

flu viruses and, one after another, they acted like garden-variety flu,

infecting only the upper respiratory tract.But a complex of three genes helped to make the virus live and reproduce deep in the lungs.The

three genes -- called PA, PB1, and PB2 -- along with a 1918 version of

the nucleoprotein or NP gene, made modern seasonal flu kill ferrets in

much the same way as the original 1918 flu, Kawaoka's team found.Most

flu experts agree that a pandemic of influenza will almost certainly

strike again. No one knows when or what strain it will be but one big

suspect now is the H5N1 avian influenza virus.H5N1 is

circulating among poultry in Asia, Europe and parts of Africa. It

rarely affects humans but has killed 247 of the 391 people infected

since 2003.A few mutations would make it into a pandemic strain that could kill millions globally within a few months.Four

licensed drugs can fight flu but the viruses regularly mutate into

resistant forms -- just as bacteria evolve into forms that evade

antibiotics.(Reporting by Maggie Fox, editing by Will Dunham and O'Callaghan)http://news.yahoo.com/s/nm/20081229/sc_nm/us_flu1918