The 1918 influenza
pandemic infected one-fifth of the world's population. On an increasingly hot,
overcrowded planet, could Ebola be our next global scourge?
By Paul R. Ehrlich The
Daily Climate
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Gloves and hospital garb worn by workers treating Ebola patients are set to dry. Some 4,200 people across West Africa have become infected since the first Ebola case was confirmed in Guinea earlier this year. Photo courtesy Jean-Luis Mosser/European Commission. |
We have a problem with
"emergent" diseases, ones that are becoming potentially serious to a
larger and more vulnerable human population. Ebola and Marburg viruses, because
of their high death rates, could become this generation's version of the flu
pandemic that swept the globe at the end of World War I.
If it does, we have
only to blame ourselves: Our degraded environment, our unchecked population
growth, our nonchalance at global poverty, hunger and disease and our
jet-setting ways.
The filoviruses are native
to Africa and commonly infect non-human primates (don't eat chimpanzee meat)
and some bats, which may be the main natural reservoir. The favorable
conditions for transfer are directly related to human population size. The more
people who come into contact with animal reservoirs and the more people who
need "bushmeat," the higher the odds of a virus transferring into
people.
A global problem
Those odds also are increased with
the number of immune-compromised people. Today that number may be in the
billions globally because of hunger, micronutrient deficiency and the
prevalence of HIV/AIDS.
Furthermore, the human population size necessary for a
self-extinguishing disease to persist is another determinant of the potential
for generating a pandemic. Needless to say, the existence of rapid global
transport systems (especially airlines) certainly makes any infectious disease
a global problem, regardless of where it first appeared among people.
The Ebola epidemic has already
involved 10 times as many people as any previous one; it has invaded Nigeria
and is moving into urban areas, spreading fast. The more people infected, the
higher the chance that its mode of transmission may evolve. If the virus
evolves – and viruses have a nasty habit of doing so – to move in droplets,
Homo sapiens could be in deep trouble.
Other threats are the possibility
that Ebola will evolve to live in new reservoirs, or that the reservoirs will evolve
in response to climate disruption. Furthermore, virulence itself may evolve,
especially in response to evolution in transmission. If Ebola evolves the
ability to be carried by, say, mosquitoes, it might become even more virulent
because immobile patients can easily be a source of virus spread.
Need for preparedness
In the current emergency, the world
should mobilize rapidly to send medical aid to isolate and treat victims in
Africa.
Beyond that effort, the world community should put much more effort into
preparedness; doing the biomedical research and building the infrastructure in
vulnerable developing countries (stocks of drugs and protective gear, more
isolation facilities, etc.) needed to guard against pandemics in general.
All nations should promote
educational programs for medical doctors and the general public that give much
more attention to the relatively neglected topics of demography and evolution
and their connections to emergent diseases. People need to understand that the
human system and the environmental system are totally intertwined and
coevolving.
Ever-changing interactions
These ever-changing interactions are
important not just from the viewpoint of pandemics. Population growth, for
instance accelerates climate disruption, since the more people there are, the
more greenhouse gases.
That disruption can clobber agriculture; as billions
more mouths to feed arrive. Climate-damaged food production presents a great
threat to the nutritional security of our grandchildren as well as the ability
of their immune systems to fight off infections such as Ebola.
Ignorance of basic evolutionary
theory is a major source of humanity's insane and self-defeating patterns of
antibiotic and pesticide use, which facilitate the evolution of resistance in
pathogens and pests.
The longer I watch the Ebola crisis
unfold in Africa, the more I'm convinced H.G. Wells had it right when he said,
"Human history becomes more and more a race between education and
catastrophe."
Paul Ehrlich is president of the Center for Conservation
Biology and the Bing Professor of Population Studies at Stanford University.
The Daily Climate and its sister site, Environmental Health News, are
independent, nonprofit news sites covering energy, the environment and climate
change. Views expressed by the author are his own and not the opinion of The
Daily Climate. Contact editor Douglas Fischer at dfischer [at] DailyClimate.org
A version of this story was published by the Millennium Alliance for Humanity and the Biosphere.
Photos of Ebola outbreak courtesy of the European Commission.