The incidence of malaria in Gambia fell substantially in five years, mainly thanks to strategies protecting pregnant women and children, researchers said.

In Friday's issue of the medical journal The Lancet, researchers reported that the proportion of positive malaria tests in the West African country fell between 50 per cent and 85 per cent from 2003 to 2007.

"The most substantial change in measures to prevent malaria has been the increase in coverage of insecticide-treated bednets," Dr. David Conway of the Medical Research Council Research Laboratories in Banjul, Gambia, and his colleagues wrote.

"These findings support the proposal that increased investment in malaria interventions in Africa can have a major effect on reducing morbidity and mortality from this disease."

Deaths from malaria at two hospitals where there were 29 fatalities out of 232 admissions in 2003, fell by 90 per cent and 100 per cent in 2007 — meaning no deaths attributed to malaria occurred that year in one of the hospitals.

During the study period, the proportion of malaria admissions at three sites fell by 74 per cent, 69 per cent and 27 per cent, the researchers found.

The increase in coverage of insecticide-treated bed nets was thanks to The Global Fund, UNICEF and the World Health Organization, the researchers said. About 49 per cent of children under five in Gambia now sleep under the nets.

Malaria deaths are highest among infants and children.

The researchers also attributed Gambia's success to programs to spray homes, and the use of more powerful drugs to replacement treatments to which the malaria parasite has gained resistance.

In September, world leaders and the heads of philanthropic organizations pledged nearly $3 billion US, aiming to eradicate the disease by 2015.

According to WHO, about 247 million cases of malaria occurred in 2006, causing nearly a million deaths, mostly of children aged under five.