Monday, January 16, 2012

Bird flu jumps to pigs - Article Sept 2010

The H5N1 bird flu virus may be evolving the ability to spread from mammal to mammal, says a team who have discovered that pigs in Indonesia have been infected with the disease since 2005. It's one step in the frightening chain of events that could lead to human transmission and a pandemic.

The H5N1 bird flu kills 60 per cent of the people it infects. However, most infections occur after direct contact with an infected bird and the disease does not appear to spread well between humans. As long as human to human transmission remains rare, the virus cannot cause a flu pandemic.

This could change. One way the virus could develop the ability to spread among humans is to first infect pigs, which have many biochemical similarities to humans. Flu viruses adapted to pigs have less trouble adapting to humans than do bird flu viruses – one pig-adapted virus caused the swine flu pandemic in 2009.

Chairul Nidom of Airlangga University in Surabaya, Indonesia, and colleagues in Japan, have been tracking H5N1 in pigs since 2005 in Indonesia, the country hardest hit by the avian flu virus. They now report that between 2005 to 2007 when the avian flu peaked, 7.4 per cent of 700 pigs they tested also carried H5N1. There have been sporadic reports of H5N1 in pigs, but this is the first time the extent of the problem has been measured. Read More