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
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
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
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.