Africa, the infectious continent With global warming, Africa is challenged by exotic pathogens.
1. Africa, the infectious continent
With global warming, Africa is challenged by exotic pathogens.
By – Mahboob Ali Khan MHA, CPHQ.
While outbreaks of new, exotic infectious diseases --as well as the resurgence of
old killers have surfaced all over the globe in the past decade, no continent has
been harder hit than Africa. But with international travelers flying viruses across
time zones in a matter of hours, experts have no doubt that the emergence of
menacing microbes in one locale could bring about a worldwide pandemic. Are
infectious diseases the new Armageddon?
Africa's tropical climate makes it a hot zone in the most literal sense. The continent
is, to put it simply, a breeding ground for emerging pathogens.
Add to that environmental changes - such as global warming and destruction of the
rain forests - rapid population growth and haphazard development, and the scene is
set for microbes to thrive, international experts have warned.
Since the mid-1970s, the world has seen the emergence of 30 new infectious
diseases and the return of such killers as malaria and cholera - many of them
originating in the African continent, said Paul Epstein, associate director of the
Center for Health and Global Environment at Harvard Medical School.
And in the past few years, floods and droughts brought on by global warming have
exacerbated the situation, he said.
“Extreme weather creates conditions conducive to outbreaks of infectious
diseases,” Epstein said. Heavy rains, for example, provide new breeding sites for
the mosquitoes that carry malaria, dengue fever and other disease, while
contaminating drinking water. Drought, on the other hand, fuels fires that, in turn,
spark respiratory ills, even meningitis.
When illness does strike Africa, a poor infrastructure - marked by poverty,
malnutrition, crowded living conditions, limited health care and an unstable
political climate - permits disease to spread undaunted.
2. Man made problem
It’s the manmade aspect of the problem that so perturbs the experts.
“These new pathogens didn’t come in on a tail of a comet,” said Dr. David
Heymann, executive director of the World Health Organization’s Program on
Communicable Diseases in Geneva, Switzerland. “They’re lurking in animals. But
by disrupting nature, we have unleashed them onto ourselves.”
The destruction of the rain forests, for example, may be partly to blame for clusters
of killer outbreaks - ranging from feverish malaria to hemorrhagic Ebola.
When trees are cut down, pools of infested water are left exposed in the forest,
Heymann said. “What we have done is set up new breeding grounds for
mosquitoes that can carry disease such as malaria.”
Dr. Anne Marie Kimball, an expert in infectious disease epidemiology at the
University of Washington in Seattle, blames deforestation for recent Ebola
outbreaks. As people penetrate the forest in search of firewood, they can be
exposed to the virus, which might otherwise have been relatively contained, she
said.
Destroying the rain forests also has led to a loss of wildlife that protects against
infectious diseases, said Epstein. “As coyotes, snakes and other predators that
normally prey upon disease-carrying rodents and mosquitoes are killed off by man
in his hunt for more wood, for example, so is our natural buffer against plague and
malaria,” he said.
“A hearty forest stocked with birds and a healthy lake stocked with fish are
important in controlling mosquitoes,” he said, which may in part explain the
resurgence of such diseases as yellow fever and malaria - the latter all but wiped
out several decades ago.
Cutting down the forest can sometimes change the mice population from forest to
field mice, Epstein added, which can bring about new viruses such as one
responsible for a deadly fever in Bolivia.
“While this has yet to happen in Africa, there is every reason to believe it can - and
will - if steps are not taken,” he said.
Globalwarming
Several aspects of climate change, all related to global warming, are contributing
the emergence of new diseases and the resurgence of others, the experts say.
3. Warming itself is allowing malaria to spread to higher altitudes, noting that the
mosquitoes that carry the disease to humans can survive only at milder
temperatures. Once confined to lower areas, the skin-piercing insects are now able
to flourish in the African highlands of Kenya.
The outbreaks have been devastating, Epstein said. With poor access to health care,
many residents were sickened and killed as malaria swept through several villages.
El Nino-related extreme weather events also brought flooding to the Horn of
Africa, chiefly Kenya and Tanzania, he said, adding that in 1997-1998, the area
was besieged with four times as much flooding as normal. The results: huge
clusters of mosquito-borne malaria and Rift Valley fever as well as an epidemic of
the water-borne disease cholera.
The big surprise, are the fires brought about by recent droughts - “something we
weren’t even thinking about a year ago.”
The fires bring haze, choking, air particulates and respiratory ills. Membranes dry,
making residents susceptible to deadly meningitis.
There’s also the impact on an already shattered economy. Due to Rift Valley fever,
which strikes cattle as well as humans for example, Africans couldn’t export
livestock, Epstein said. Cholera-infested waters limited the sale of fish.
Mahboob- ali khan -Communicable diseases account for 63 percent of deaths in
the African region, with emphasis on HIV/AIDS and tuberculosis, According to
WHO statistics on the global burden of disease, about 59 million people died in
2008 and almost 18 percent of these occurred in the African region, the home to
about 12 percent of the world population. Africa: Infectious Diseases Account for
63 Percent of Deaths in THE Continent - WHO Official.