London: A study published Thursday casts
doubt on the widely held notion that warming global
temperatures will lead to a future intensification of malaria
and an expansion of its global range.
The research, conducted by the Malaria Atlas Project
(MAP), a multinational team including Oxford University
researchers, suggests that current interventions could have a
far more dramatic and positive effect on reducing the
spread of malaria than any negative effects caused by climate
The study has been published in the journal `Nature`,
an Oxford University release said.
A steady stream of modelling studies have predicted
that malaria will worsen and its range will spread as the
world gets warmer.
Malaria already kills more than a million people each
year, mainly young children and pregnant women, with some 2.4 billion people at risk from its most deadly form.
Last year the Malaria Atlas Project produced a new
map of modern-day malaria risk, giving researchers a unique
opportunity to examine the effects that climate change may
have had on the disease.
The new research compared this modern-day map with a
historic reconstruction of malaria at its assumed peak, around
1900, and measured changes in the disease risk since that
Although it is widely known that malaria has receded
from many areas where it was previously endemic, such as the
United States and much of Europe, the researchers were able to measure for the first time the extent of this recession and
show that even in tropical areas the intensity of transmission
has declined substantially this century.
"The recession in malaria since 1900 is of little
comfort to the billions of people still at serious risk, but
it is important when thinking about the effects of climate on
the future of the disease," said Dr Pete Gething of Oxford`s
Department of Zoology, who led the research.
"We know that warming can boost malaria transmission
but the major declines we`ve measured have happened during a century of rising temperatures, so clearly a changing climate
doesn`t tell the whole story."
The team compared the increases in malaria predicted
by global warming scenarios with the actual declines of the
Importantly, they also gauged the efficacy of
different disease control measures when set against the
possible adverse effects of rising temperatures and concluded
that interventions such as insecticide-treated bed nets or
modern antimalarial drugs can potentially outweigh the effects
of global warming as much as tenfold.
"When we looked at studies measuring the possible
impact of bed nets or drugs, it was clear that they could
massively reduce transmission and counteract the much smaller effects of rising temperatures," said Dr Simon Hay, who leads the MAP group in Oxford.
"Malaria remains a huge public health problem and
the international community has an unprecedented opportunity
to relieve this burden with existing interventions.
Any failure in meeting this challenge will be very
difficult to attribute to climate change."
A report of the research is titled, `Climate change
and the global malaria recession`.