TRUAX,
Saskatchewan, Canada, posted October 18, 2007: It's
pretty easy for the average person to get lost in the acronyms
around avian influenza, but you can bet chicken farmers know
what they mean. Saskatchewan's outbreak of the H7N3 strain
of the virus (not to be confused with the H5N1, which is linked
to human illness) left a lot of concern in the poultry industry.
Due partly to supply management, Canada is not a big exporter
of poultry, so the border closures that accompanied the outbreak
were less serious than they might otherwise have been. Measures
developed after B.C's outbreak of the H7N3 strain in 2004
left the industry better prepared to deal with this problem.
Nevertheless, there is a great deal of worry around the globe
concerning what are called Highly Pathogenic Influenza A viruses.
The science around the development and spread of these viruses
is evolving continually, but can be coloured by the special
interests involved. To understand the debate, a few concepts
are needed.
Highly Pathogenic viruses are ones that spread rapidly and
are deadly. A large percentage of infected birds will die.
There are also Low Pathogenic versions of Influenza A. These
occur everywhere in birds, both wild and domestic, but are
rarely fatal. Where they are found in tame poultry, it is
believed they come mainly from wild birds.
The Low Pathogenic versions are not too significant, since
fowl have lived with them for ages. What is important is that
this virus, Influenza A, is able to undergo molecular transformation
that allows it to adapt to new hosts and potentially cause
major disease outbreaks in birds, but also in humans.
Old thinking: factory farms safer
When the H5N1 version appeared in Asia, scientists began
to speculate both on its origins, and how it was spread. Readers
may remember that the first to be blamed were wild birds and
small, backyard chicken flocks. It was thought that the disease
came from wild fowl, and easily spread to the chickens scratching
around the back yards of rural and urban dwellers in crowded
Asian countries.
Large confinement poultry farms, often owned by multinational
agribusiness companies, were quick to point the finger there,
and demand small flocks, as reservoirs of the disease, be
eliminated. After all, how could flocks confined entirely
in buildings have come in contact with the disease-carrying
wild birds?
This thinking was also promoted by agencies working to promote
economic development in poor countries. Organizations like
the United Nation's Food and Agriculture Organization have
long promoted intensive rearing of animals like hogs and chickens
as a way of enhancing the quantity and quality of food available
in underdeveloped countries. Thus the idea that small flocks
might be a health risk fit nicely into the agendas of a number
of players—governments, large agribusiness corporations
and agencies like the FAO and the World Bank. Countries were
warned to watch for a spread of Avian Influenza when fall
bird migrations began in the northern hemisphere.
A number of scientists and ecology groups challenged this
whole notion. And new evidence seems to show they were right.
Highly Pathogenic viruses do not appear to be common in wild
fowl. Sampling of wild bird populations around the world has
shown this. It is now believed that the Highly Pathogenic
strains of Avian Influenza appear in domestic poultry as a
result of molecular changes in existing versions of the Influenza
A virus in domestic flocks. In light of this the FAO is doing
some re-thinking of its ideas about poultry.
In a report issued last week, the FAO suggested that a worldwide
shift to concentrated intensive livestock operations has "potentially
serious consequences for local and global disease risks, which,
so far, have not been widely recognized."
New thinking: think again
The report pointed to the industrial style of these production
units as a potential source of both the development and rapid
spread of pathogens. In an about-face from past policies,
the FAO stated that "policy makers in both developing
and developed countries appear to accept that large-scale
industrial farms have higher standards and self-discipline
in biosecurity, while smallholders need more rigorous public
oversight. But the realities of animal health, economic incentives,
and the public interest in disease prevention are far too
complex for simple rules of thumb like this to be optimal
for society."
This change of heart on the part of the FAO will hopefully
accompany a lot of sober second thought about the nature of
development. Millions of poor around the world depend on backyard
poultry flocks to supply a modest amount of protein and some
badly needed cash. In a country like Vietnam, for example,
more than half of all households, urban and rural, raise poultry.
In isolated rural areas, the figure reaches 90 percent. An
average flock in Vietnam consists of about 16 birds (4 hens,
1 cock and 11 growers and chicks). The poorer the family,
the greater a contribution to family income the poultry flock
makes in Vietnam.
The introduction of intensive poultry rearing in countries
like Vietnam usually reduces the value of birds raised by
small farmers. Many development agencies have recognized this,
but have been unable to overcome the belief that the greater
"efficiency" of these operations will provide greater
overall benefits.
The idea that these intensive operations may be a major concern
in the development and spread of Highly Pathogenic viruses
should give all governments some pause to reconsider this
form of industrialization.
|
