Friday, July 16, 2010

Fighting Malaria with Genetically Modified Mosquitos

This study in the latest issue of PLOS Pathogens suggest this might not sound as bizarre as it appears. Here is the abstract:

Malaria (Plasmodium spp.) kills nearly one million people annually and this number will likely increase as drug and insecticide resistance reduces the effectiveness of current control strategies. The most important human malaria parasite, Plasmodium falciparum, undergoes a complex developmental cycle in the mosquito that takes approximately two weeks and begins with the invasion of the mosquito midgut. Here, we demonstrate that increased Akt signaling in the mosquito midgut disrupts parasite development and concurrently reduces the duration that mosquitoes are infective to humans. Specifically, we found that increased Akt signaling in the midgut of heterozygous Anopheles stephensi reduced the number of infected mosquitoes by 60–99%. Of those mosquitoes that were infected, we observed a 75–99% reduction in parasite load. In homozygous mosquitoes with increased Akt signaling parasite infection was completely blocked. The increase in midgut-specific Akt signaling also led to an 18–20% reduction in the average mosquito lifespan. Thus, activation of Akt signaling reduced the number of infected mosquitoes, the number of malaria parasites per infected mosquito, and the duration of mosquito infectivity.

And the Globe has the scoop here. A sample:

Scientists have developed the first genetically modified mosquito (GMM) that is completely immune to the disease the insects so efficiently spread. An estimated 250 million people worldwide contract the deadly blood-borne disease a year; one million of them die.

The GMM mosquitoes will still bite; they just won't leave behind the malaria-causing parasite, called Plasmodium.

“Hopefully, down the road this will play a part in controlling malaria,” says lead researcher, entomologist Michael Riehle. The research was published Thursday afternoon in the journal Public Library of Science Pathogens.

Although releasing the new mosquito into the wild is a long way off, Dr. Riehle says that given the drawbacks of other malaria-fighters, especially the mosquito's growing resistance to various insecticides and vaccines, it is a method worth investigating.