An estimated one million people die each year from malaria, a parasitic infection transmitted by mosquitoes. Current control strategies involve blasting the bugs with insecticides, or using drugs to kill the parasite once it infects humans. Unfortunately, these methods are becoming less effective as both pests evolve ways to resist the toxic treatments, so new methods to prevent malaria are sorely needed.
In recent years scientists have tinkered with the insect’s genes with hopes of developing modified mosquitoes incapable of transmitting the parasite. Although promising, these efforts produced mosquitoes with only reduced parasite transmission. Now, researchers led by University of Arizona entomology professor Michael Riehle report that they have developed a transgenic mosquito that is completely immune to infection by Plasmodium falciparum, the primary malaria-causing parasite in humans. The researchers hope that their findings will one day be used as part of a new strategy to combat malaria.
For malaria to spread, a female Anopheles mosquito must first ingest the parasite by dining on an infected person. Once inside the mosquito, the parasite undergoes an approximately two-week maturation process, traveling from the mosquito gut to the salivary gland where it is then ready to be spread to other human hosts.
Fortunately for humans, mosquitoes in malaria-endemic regions rarely survive more than two weeks. Therefore, the researchers sought to investigate ways to shorten the mosquito’s lifespan because “even a modest reduction in lifespan could significantly impact parasite transmission,” the authors wrote in their paper, published online July 15 in PLoS Pathogens.