A study by scientists at Glasgow University and the Wellcome Trust Sanger Institute, near Cambridge, has unlocked the long-standing mystery of how the malaria parasite initiates the process of passing from human to human.
Malaria is transmitted to people through the bites of mosquitoes which have themselves been infected by the Plasmodium parasites that cause the disease.
The team has identified a single regulatory protein which acts as the "master switch" that triggers the development of male and female sexual forms - known as gametocytes - of the malaria parasite.
If the malaria parasite is unable to take that crucial sexual developmental step, then transmission of the disease can no longer take place.
The researchers spent more than three years using highly-sophisticated genome sequencing techniques to identify mutants of the protein which prevent the development of gametocytes.
The discovery means this "transmission switch" could be disabled in future through the development of new drugs.
Professor Andy Waters, director of the Wellcome Trust Centre for Molecular Parasitology at Glasgow University, said: "Malaria is the biggest parasitic disease killer that there is in the world, so clearly we need to combat that. There are drugs, but they are losing their efficacy because the parasite is becoming resistant. There is currently no vaccine."
Any drug treatment developed as a result of this research is likely to be what scientists describe as an "altruistic intervention", where the drug would be taken by adults who were already infected by malaria but had developed resistance to the disease.
The drug would block the "transmission switch", thus preventing re-infection or infection to, for instance, their children. It is anticipated many parents would agree to take such a drug if it meant offering greater protection to their children.
The research is published in the journal Nature.