Historically, doctors, researchers and scientists have tried to figure out both 1) how to develop a malaria vaccine and 2) how to best kill or avoid mosquitos. A new approach that does neither may be more promising than any other previous breakthrough.
At Johns Hopkins, scientists have been toying with the idea of killing the malaria parasite itself, rather than the mosquito. They have been able to do this by genetically engineering bacteria that can kill the parasite.
Previously, these same scientists were trying to devise ways to genetically engineer mosquitoes so that they would be resistant to malaria. That proved to be too great of a challenge — not because it was difficult scientifically, but because it was difficult ethically. Furthermore, these new malaria resistant mosquitoes would have required some kind of edge that would allow their genes to propagate over other mosquitoes.
So, they changed course and started thinking about how to attack malaria itself. They used genetic modification once more, but in this case, they did so with bacteria, which while still inspiring a discussion on ethics, seem to exist on a different plane entirely.
By putting the engineered bacteria into the mosquitoes’ food supply, the scientists were able to get the bacteria into their gut where it can go to work. Mosquitoes feed on plant juices and nectars for most of their lives. It is typically only before a female produces eggs that she needs to have a blood meal.
Once the bacteria was in the gut of the mosquitoes, the scientists then had the mosquitoes take a blood meal of blood that was infected with malaria. The results were rather astonishing:
“It was amazing,” said Jacobs-Lorena: The proportion of mosquitoes carrying the parasite dropped by 84% and overall parasite levels dropped by more than 90%.
Despite the encouraging results, it may be some time before this bacteria is introduced to the wild. For that to happen, legal regulations will have to be established and the bacteria will have to clear more scrutinizing tests. For now, however, there is reason for optimism. It is rare to see such convincing results where malaria is concerned.
For a more detailed account of research on this type of genetic engineering, check out this piece from the Los Angeles Times.
Photo credit: CDC