New Scientist (September 11 – 17, 2010 issue 2777)
H5N1 bird flu virus may be evolving the ability to spread from mammal to mammal, the crucial change that could lead to a pandemic, according to a team that has tracked infected pigs in Indonesia since 2005.
The H5N1 strain kills 60 per cent of infected people. However, most infections occur after direct contact with an infected bird and as long as human transmission remains rare, the virus cannot cause a pandemic.
Chairul Nidom of Airlangga University in Surabaya, Indonesia, and colleagues, has been tracking H5N1 in pigs in Indonesia. In each case, the virus in pigs closely resembled H5N1 from nearby outbreaks in poultry, suggesting it had jumped from birds to pigs. That, and the small proportion of pigs infected, suggests the virus cannot yet spread readily from pig to pig.
But Nidom says that in one pig, the virus had developed the ability to bind to a molecule present in the noses of both pigs and humans - exactly the kind of change that could allow it to spread easily between people
Influenza A (H5N1) Viruses from Pigs, Indonesia
Chairul A. Nidom, Ryo Takano, Shinya Yamada, Yuko Sakai-Tagawa, Syafril Daulay, Didi Aswadi, Takashi Suzuki, Yasuo Suzuki, Kyoko Shinya, Kiyoko Iwatsuki-Horimoto, Yukiko Muramoto, and Yoshihiro Kawaoka
Emerging Infectious Diseases,2010 October epublised before print doi: 10.3201/eid1610.100508).
Link to EID article [pdf]