February 1, 2006

Early warning system predicts malaria epidemics

By Patricia Reaney

LONDON (Reuters) - An early warning system based on climate
models, average rainfall and data on seasonal malaria can
predict the risk of an epidemic of the killer disease five
months in advance, scientists said on Wednesday.

The system has been devised by researchers in the United
States, Britain and Botswana.

"We can give warnings of high risk of an epidemic to the
health agency and officials in the country ahead of the rainy
season. This is something they have not had before," said Tim
Palmer, a climate modeller at the European Center for Medium
Range Weather Forecasts in Reading, England.

Malaria, a parasitic disease transmitted by mosquitoes,
kills more than a million people a year, mostly young children
in Africa.

Changes in climate and rainfall have an impact on the
seriousness of a malaria outbreak. In countries like Botswana,
where the system was tested, the risk of an epidemic increases
after a season of heavy rain.

The system would enable health officials to take
preventative action such as spraying stagnant water or
supplying antimalarial drugs earlier.

"If you leave it until the end of the rainy season, it is
pretty much too late because the malaria kicks in very soon
afterwards," Palmer told Reuters. "We're talking about pushing
the prediction horizon back several months, which really does
give a lot more lead time."

Palmer and his colleagues, along with scientists from the
Earth Institute at Columbia University in New York and the
Ministry of Health in Botswana, used several climate models to
forecast high and low incidences of malaria.

Using the system, they retrospectively predicted malaria
outbreaks in Bostwana from 1982 to 2002, according to the
research reported in the journal Nature.

"What we have demonstrated in this project, which makes it
unique, is the speed at which cutting-edge climate research can
be translated into operational activity in Africa," said
Madeleine Thomson of the Earth Institute at Columbia University
and a co-author of the report.