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Researchers
convinced satellites are helpful in tracking epidemics
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A dust storm
moving across Africa's western Sahel belt on 3 March 2004, as
seen by MSG-1, now renamed Meteosat-8. Dust storms are being
mapped as part of the ESA-led Epidemio project.
Credits: EUMETSAT
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13 March 2006
The amount
of data acquired by satellites is increasing at an exponential
rate, and researchers are learning about the value of this data
in fighting epidemic outbreaks as a result of the ESA’s
Epidemio project.
"I was negative about the
role satellites could play in addressing epidemics, but now I am
positive," Penelope Vernatsou of the Swiss Tropical
Institute in Switzerland said.
The ESA-funded Epidemio project
was developed in January 2004 to illustrate the benefits of
remote-sensing data for studying, monitoring and predicting
epidemic outbreaks.
By using
data which focuses on a region’s landscape –
rainfall, vegetation, water bodies, elevation, dust mapping and
temperature – researchers are able to pinpoint climatic
conditions which are favourable for harbouring various epidemic
hosts, indicating where people are at greatest risk.
As the project draws to
completion, epidemiologists and data users gathered in Frascati,
Italy, at the ‘Earth Observation in Epidemiology Workshop’,
on 8-10 March 2006, to report on how Earth observation (EO) has
benefited the field of epidemiology.
Ghislain Moussavou of the
Gabon-based International Centre for Medical Research (CIRMF)
began studying Ebola haemorrhagic fever, which can cause runaway
internal and external bleeding in humans and apes, in Congo and
Gabon in the hope of spotting particular environmental
characteristics associated with infected sites.
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Extract of a
radar image centred on a cliff which works as a geographical
barrier between two regions in the studied area : on the
left, outbreaks have been registered, on the right, none have
taken place. Satellite data being supplied to CIRMF
researchers may help highlight patterns in the way Ebola
strikes to help discover the mysterious host organism of the
virus.
Credits: CIRMF
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A Congolese
family pose in their kitchen in the village of Mbomo, 10
November 2004. Fifteen members of the family died last year
when in an Ebola outbreak spread through the region. The
disease is highly infectious and easily transmitted through
contact with the blood and other body fluids of victims, even
when they are dead. Locals seemed to have learned the lessons
taught by authorities in the capital Brazzaville, or by the
Red Cross and relief aid workers. "We don't eat monkey
meat and we don't collect dead meat any more," villagers
chorused. One of the dangers has been eating dead animals
found in the forest such as gorillas, considered the likely
origin of the virus jumping to humans.
Credits:
AFP/ALEXANDRA LESIEUR
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Combining ESA Envisat
satellite data, under the Epidemio project, on water bodies,
forest cover and digital elevation models (DEMs) with field
results, Moussavou and his team were able to link the epidemic
with dryness and drought.
Moussavou
said determining these factors will allow officials to tell the
villagers in the area that current conditions for transmission
are high, and that they need to take extra precautions. "Because
there are no medicines to prevent or cure Ebola, predictions and
prevention are necessary."
Dry conditions are also
favourable for the spread of meningitis, an inflammation of the
brain and spinal cord lining. Epidemics nearly always start in
the early part of the dry season when it is hot and dusty. For
this reason, ESA has been providing dust maps for high-risk areas
to aid in implementing early warning systems.
Christelle Barbey of Silogic,
in France, is currently involved in an Epidemio project to
provide wind blown dust maps for Africa. Although her final
results are still coming in, she was able to detect 100 percent
of known dust events, using MeteoSat data, and determine that
dust maps do correspond to a user need to contribute to
meningitis prevention.
The Epidemio project –
funded by the Data User Element of the ESA Earth Observation
Envelope Programme – concludes its two-year mission in
April 2006, but the groundwork it has laid will aid users in the
continuance of their research and allow new projects to be
undertaken.
Giuseppe
Ottavianelli and Aude de Clercq of the HISTAR Solutions in the
Netherlands are currently working on a project, backed by ESA
business incubator financing, to confirm the onset of malaria
epidemics in Africa, as predicted by remote sensing data.
They have designed a prototype
of a sensor located in a box that detects mosquitoes as they fly
overhead. The data collected by the sensor is then processed by a
program inside the box, which will be placed in hat hutches in
high-risk African villages, and indicates the species and numbers
of the mosquitoes detected.
Malaria is transferred by the
female mosquito of the species Anopheles, so if the sensor
detects her presence in high numbers, public officials will be
alerted so that preventive measures can be put into place.
Source / Credit: ESA
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