Malaria deaths have fallen by more than 25 percent in the last decade, thanks to a coordinated attack on the disease, but that progress remains fragile, the World Health Organization announced this month.

About 655,000 victims — mostly children — died of malaria in 2010, the report estimated. A decade ago, estimates were closer to a million, though the counting was shakier.

The biggest gains were made in Africa, where a vast majority of the deaths occur and where donor dollars have been concentrated since the Global Fund to Fight AIDS, Tuberculosis and Malaria and the President’s Malaria Initiative were created early in the decade.

However, the report warned, that progress could easily evaporate. Malaria rebounded in the 1970s when mosquitoes became resistant to pesticides and the parasites that cause the disease became resistant to chloroquine. Eradication programs begun in the colonial era fell apart as newly independent countries sank into poverty.