Washington | Scientists have found that resistance to a key anti-malarial drug cannot be passed on by mosquitoes, a breakthrough that could drastically improve the way we battle the disease.
The discovery could potentially shut down the avenue for mass drug resistance to spread, making malaria treatment significantly more effective for the 3.2 billion people at risk, researchers said. The international research project was led by the University of Melbourne and focused on the drug atovaquone.
Atovaquone was introduced in 2000 and is safe for pregnant women and children, so it is one of the few anti-malarials that can be used in mass administration approaches, researchers said. It was largely phased out of use because resistance was initially observed.
The study shows that although some malaria parasites had developed a genetic mutation that protected them against the drug in early life, the mutation eventually killed the parasites by stopping production of an essential type of energy as they grew. Geoff McFadden and Dean Goodman described it a ‘genetic trap’ that could prove to be a significant step forward in the anti-malaria fight.
The pair, along with collaborator Vanessa Mollard, led a team investigating the evolution and life cycle of the malaria parasite for the past six years. These results are very exciting because the spread of drug resistance is currently destroying our ability to control malaria, said McFadden, from the School of Biosciences at the University of Melbourne.
We now understand the particular genetic mutation that gave rise to drug resistance in some malaria parasite populations and how it eventually kills them in the mosquito, providing new targets for the development of drugs, McFadden said. So the development of drug resistance may not be a major problem if the resistance cannot spread, meaning the drug atovaquone could be more widely used in malaria control, he said.
The researchers studied a model strain of rodent malaria and a deadly strain of human malaria to confirm the resistant parasites could not be spread by mosquitoes, thereby preventing the re-infection of humans. It is very rewarding that our fascination with basic biology has produced such significant results, said researchers.
We are the first group to follow the drug resistant malaria parasite through its entire life cycle to understand what happens after drug resistance initially develops and whether they pass on resistance, they said. The study was published in the journal Science.