Dear Martin,
Much like the recent article by Laurie Garrett, this article is peppered with statements and half truths that do not accord with the situation on the ground.
Of particular importance is the fact that much of the disease in smallholder poultry goes undiagnosed. In countries with poorly developed veterinary services it is only when a case occurs in a commercial farm that the problem is diagnosed and brought to the attention of veterinary authorities.
A clear distinction needs to be made between farms that have in place sound biosecurity systems, which usually remain free from disease, and those where production systems are inadequate to prevent entry of pathogens.
I note that Lao PDR has been used again as an example of a place where all outbreaks occurred in commercial flocks – but these were not high level, biosecure farms.
Much of the problem in Asia has been caused by farms developing to service the rapidly growing urban demands for poultry without concurrent enhancement of farm biosecurity (i.e. a backyard flock grows bigger). This is not being driven by the big multinational companies but by smallholders who see the economic benefit of servicing these markets. These farmers grow more birds under fairly primitive conditions and do not implement appropriate disease control measures. The solution to this problem is to enhance the biosecurity of these farms.
This article also suggests that the virus needs to circulate in poultry to become pathogenic. This is not the case with the H5N1 viruses circulating currently. These are already highly pathogenic from the moment they enter a flock and have been since 1996.
As I have stated many times this is predominatly a disease of poultry but it is incorrect to blame its emergence on intensive farming.
Regards,
Les Sims
Post edited by: martin, at: 2006/03/01 15:59