The instances of malaria worldwide have decreased dramatically since 2000. Mortality has been reduced by 42 percent. In the African region where it is most rampant, malaria deaths have been reduced by nearly half. Much of the progress has been attributed to aggressive efforts on the part of the World Health Organization (WHO) and governments in high risk areas to control the spread of the disease. Key interventions include use of insecticide nets, indoor spraying to control the mosquitoes and prompt treatment with specialized drugs.
While malaria still remains a leading cause of death in many places, progress in the reduction of malaria over the past two decades has led WHO to begin a shift in focus from controlling malaria to elimination planning.
Malaria is caused by a parasite called Plasmodium, which is transmitted via the bites of infected mosquitoes. In the human body, the parasites multiply in the liver, and then infect red blood cells. Symptoms usually appear within 10-15 days of the bite and can quickly become fatal if not treated promptly with medicines. The current most effective treatment is called “Artemisinin-based combination therapies (ACTs).” Artemisinin is a plant-based derivative from soft wormwood, which when combined with a partner drug has proven to quickly remove a number of the parasites in the blood. Expanding access to this drug in at risk countries has been credited with the rapid reduction in malaria-related deaths.
However, just as scientists have gotten the upper hand in fighting malaria, the parasite has developed resistance to the most effective treatments.
Southeast Asia has reported that the parasite has become resistance to the drug, with documented cases in five countries. In 64 countries, the mosquito that carries the parasite has developed resistance to at least one of the insecticides used in 64 countries. While the interventions used still remain highly effective, the reported resistance is worrying. If it continues and spreads, a world health crisis could develop. There are currently no alternatives as effective as the ACTs in treating the disease.
Now a team of Australian scientists may have just found the key for new drug development.
In a report published this month, three Australian scientists have put into practice a theory developed in 2009. It was understood that after the malaria parasite was inside the red blood cells of the liver, it starts spreading its proteins through the blood cell cytoplasm, which helps it survive and absorbs nutrients. As the co-author of the study Tania de Koning-Ward explains, ‘’There are hundreds and hundreds of proteins that the parasite needs to get across into the red blood cells and this study has shown that there is only one way for all the proteins to get out into the red blood cells. If we block that pathway, then we kill the parasite.”
In lab tests, they were able to deny the parasites the proteins and effectively kill it within six hours, stopping it before it had a chance to multiply.
As the race to create new treatments continues, new drugs using this kind of mechanism would be a particularly potent solution. Any new drug, however, could be ten years and a half a billion dollars away. Nevertheless, the discovery is significant and brings new hope to the reality that malaria could not only be controlled, but effectively be eliminated within a few decades.
Photo:Malaria 3-D rendering via Thinkstock