UPDATED AT 1:38 PM EDT Monday, Jul. 7, 2003
The Globe and Mail (CANADA)

Canada may finally be getting some relief from its latest worrisome
diseases. SARS is declining in Toronto and, in Alberta, there have been
no new cases of Creutzfeldt-Jakob -- mad-cow disease. It's time now to
ask where these diseases are coming from and what can be done to prevent
them.

SARS and mad-cow represent what's known as zoonotic infections --
diseases transmitted from animals to humans. Researchers believe SARS
was spread to humans from a cat-like animal, the masked palm civet,
regarded as a delicacy in southern China where the illness festered for
months before going global. Mad-cow is transmitted by eating infected
cattle.

>From SARS, to West Nile virus, to Ebola fever, humans are catching our
animal cousins' diseases. In the medical world, we are frequently told
that the cross-species jump of infections is wildly improbable -- until
it occurs. Currently, we have had no idea what is coming in the future
until we get an epidemiological retrospective of what has occurred in
the past.

Evidence indicates chimpanzees from central Africa are the original
source of the HIV/AIDS epidemic, and that transmission was through a
simian immunodeficiency virus (SIV). The source of human contact is
thought to be exposure to blood from chimpanzees killed for "bush meat."

The bush-meat crisis -- the slaughter of animals such as chimpanzees,
gorillas and bonobos for meat -- has increased as logging companies
build roads deep into formerly unreachable forests, allowing hunters
easier access to prey. Almost more worrisome than HIV/AIDS is that new
research has identified other SIVs in other African primate species,
raising the possibility of more catastrophic epidemics with the
increased consumption of bush meat.

Ebola, one of the world's deadliest diseases, has killed 114 out of the
128 humans who contracted it in the latest outbreak in the Congo.
Although not the primary carrier of Ebola, gorillas are the likely link
in the most recent outbreak. They succumb to Ebola, and in turn, the
virus is passed on through the consumption of their meat. In the
November, 2002, outbreak alone, the disease is estimated to have killed
between 600 and 800 Western Lowland gorillas. The decimation of the
world's great apes and other primates can be seen not only in ethical
terms and scientific loss, but also represents a clear and present
danger to global health.

Humans have a long history of catching animal-borne viruses. Of the more
than 1,700 known viruses, bacteria and other pathogens that infect
humans, about half come from animals. When our ancestors descended from
the trees, they picked up parasitic worms from animals on the savannah.
When humans migrated from the savannah to Europe and Asia, new
infections emerged such as bubonic plague from rats; gangrene, tetanus
and brucellosis, largely from eating wild game. When humans began to
settle into farming societies, more zoonotic illness emerged. Not so
long ago, we caught measles from dogs and tuberculosis from cows.

So are animal-borne diseases not inevitable? Growing evidence suggests
the process may be accelerating due to massive demographic changes and
environmental degradation. In central Africa, the forced relocation of
huge populations under colonial rule, rapid urbanization, and the
logging that opened the forest to bush-meat hunters has set the stage
for even more spread of disease. Add to this mix a very poor
public-health infrastructure and civil unrest. In Asia, it is not
surprising the SARS epidemic came from southern China, where the
proximity of wild animals -- many shipped in from tropical zones -- and
domestic animals within human settlements has supplied the perfect
breeding ground for a new genetically recombined virus. The risk is
compounded because consumers and animals are often not from similar
ecosystems and have not co-existed for long periods of time.

Consumption of bush meat in Asia and Africa has gone from occasional
domestic use to a rapidly growing commercial enterprise. In middle
Africa, this is largely due to huge Western logging initiatives; in
Asia, to growing economic power and increased trade with neighbouring
countries -- allowing many more people to indulge a tradition of eating
wildlife dishes called ye wei -- literally , "wild taste."

Biodiversity is richest closest to the equator, the very area where
burgeoning human populations exist -- many living in poverty and extreme
heat without access to running water, the perfect conditions for viruses
to fester and emerge as new zoonotic disease. Contemporary global travel
guarantees that virtually any place on Earth can be reached within 36
hours, in many cases, time enough to allow for incubation before
symptoms emerge.

The belief has been that developing nations have more urgent priorities
than conservation of animal species. The false dichotomy is: people or
the environment. The reality is the two are inseparable; destructive
environmental practice produces high costs at all levels of development.

How can we prevent a new animal-borne disease from becoming the next
pandemic? The answers will be found in a weave of environmental
protection, poverty alleviation and global health initiatives. The
often-ignored growing inequality in access to basic standards of human
health and wellbeing is staggering. We now know that this comes at a
high price.

Somehow, ethical considerations have not been enough to act. Let us hope
the threat to global health will be.

University of Toronto bioethicist Kerry Bowman is founder of the
Canadian Great Ape Alliance.