Regular doses of the drugs could improve performance in school, research by Kenyan and British experts suggests.

Malaria is estimated to account for a million child deaths a year in sub-Saharan Africa.

Many schoolchildren continue to harbour malaria parasites without displaying any symptoms of disease.

The study involving almost 5,000 school children in western Kenya found that administering a full course of anti-malarial drugs three times a year led to a dramatic reduction in infection rates.

The study suggested a link between malaria infection and an increased risk of anaemia.

Improved performance

Dr Willis Akhwale, the head of the National Malaria Control Programme in Kenya, says results show that anaemia could be a major cause of poor performance in school.

"If they are given this medicine, then you see their performance improving," he said.

"If you prevent malaria infection, then you reduce the chances of anaemia and the children therefore have better attention while in school and slowly over time, you see them improving in their educational achievements."

Dr Akhwale says taking the anti-malarial drugs three times a year does not pose any risk of side-effects or lead to the development of resistance to malarial drugs.

"If we're using the right quality of medicine, and we strictly supervise this taking of medicine three times in a year, that would be useful," Dr Akhwale says.

The four-year study was carried out by researchers from Kenya's University of Nairobi and the London School of Tropical Medicine.

Dr Akhwale hopes they will be able to conduct a larger study over a longer period of time to confirm the results.

The study could help promote the establishment of school-based malaria prevention programmes.

There are several internationally-backed initiatives to tackle malaria - for example Roll Back Malaria, which aims to halve malaria deaths globally by 2010.

More than half a billion people are infected with malaria each year.

BBC