Bird flu focus shifts to mid-sized farms

Mid-size traders and farms that sell poultry to small farmers could act as bird flu transmission hubs and there needs to be to better biosecurity at that level, a top UN expert said on Tuesday (April 20).

Bird flu outbreaks have generally been dealt with by culling birds, but health authorities are now trying to look up the supply chain to identify possible sources of infection, said David Nabarro, the UN's senior coordinator for avian and pandemic flu.

"We are finding that if we have a much clearer understanding of the patterns of movement of the virus, and in particular build-up points, we can then do much more sophisticated control strategies that have less economic damage for poorer people and more impact," Nabarro said.

Juan Lubroth, Chief Veterinary Officer at the UN's Food and Agriculture Organisation, said better management of animal stocks and farms was needed, but he worried that the message was not getting through.

Lubroth estimated that the mid-sized farms Nabarro mentioned accounted for 60-70% of farmed animals, but said systems were not in place to comprehensively monitor diseases among animal populations that may become a threat to humans.

"Not just influenza, we want to be tracking other pathogens of concern -- and not just emerging infectious diseases, there are some very old diseases that we know about that we are not doing enough about such as rabies or tuberculosis or foot and mouth disease (FMD)," he said.

Almost all of the human H5N1 infections to date were believed to have taken place directly from birds to humans, but health experts fear it could mutate to a form that could be easily transmitted human-to-human, sparking a deadly global pandemic.