New insights into parasite reproduction aids malaria research
Scientists have found that upsetting the mating pattern of the parasite that causes malaria could stop its spread between people.The tropical disease is caused by the malaria parasite Plasmodium, which can infect both humans and cattle. It is a major problem in Sub Saharan Africa and causes a death toll of one million people every year. This disease especially threatens children, pregnant women and elderly people.
Its transmission between humans is caused by the bite of mosquitoes which carry the parasite from one infected person to its next victim. Recent research by scientists from the Universities of Edinburgh and Oxford have found that the parasite is vulnerable at a stage when it has formed male and female cells in the bloodstream of its host. These germ cells are one of several stages in the complex life cycle of malaria. Biting mosquitoes pick up the parasite at this stage of its life cycle and they then breed inside the gut of the mosquito to produce the offspring.
The team used these sexual cell forms in their study. They killed either the female or the male cells. In both cases this did not stop the spread of the infection. This is because the remaining parasites replaced the lost ones which could then be further passed on. It was discovered that when cells of both sexes were not killed but just damaged, the parasites did successfully reproduce. However the next generation could not survive and as a result the transmission cycle was interrupted as the mosquito would not be able to infect a new victim.
Ricardo Ramiro, who was part of the team said: “Our studies show that inflicting just the right amount of damage could be the best way to interrupt the malaria parasite’s development in the mosquito and help prevent the spread of disease.” This shows that to stop the transmission of malaria less damage is more successful than killing some parasites but not all.
The complete study was published in PLoS Pathogens, and was funded by the Portuguese Foundation for Science and Technology, the Royal Society, Balliol College Oxford and the Wellcome Trust.