Scientists have blocked the sexual development of the malaria parasite in the laboratory, opening the possibility of a drug that could sharply reduce the disease's spread, according to a new study.
When a mosquito bites an infected human, it sucks up the gametes, or sex cells, of the malaria parasite at the same time that it feasts on the blood.
The sexual cycle of the Plasmodium falciparum parasite continues inside the mosquito, producing cells that are transmitted in its saliva the next time the insect draws human blood with its needle-like proboscis.
The gametes do not provoke malaria's terrible symptoms, but settle in the liver where they eventually give rise to the parasite that does.
A team of researchers at the London school of Hygiene and Tropical Medicine led by David Baker discovered an enzyme critical to the parasite's sex cycle, and developed a means for arresting it.
"It acts as an inhibitor that stops the parasite from developing sexually," Baker told AFP.
"If we could develop a drug for patients, it would enable us to block malaria transmission from individual to individual" via the species of mosquitoes that carry the disease," he said.
Malaria severely sickens half-a-billion people in the world each year, and kills more than a million. Ninety percent of victims live in sub-Saharan Africa, and the vast majority of those are infants and children.
Baker said that the drug might also have a curative effect, though the study, published in the open-access online science journal PLoS Biology, only focuses on the spread of the disease.
Each day, some 3,000 young lives -- one every 30 seconds -- are snuffed out by malaria. The disease also saps more than a full percentage point from the annual economic growth of the most affected nations.