LOS ANGELES — Malaria kills nearly 1 million people a year, but it has a weakness: To infect humans, it needs mosquitoes. In a potential step toward eradicating the disease, researchers reported they have developed a genetically engineered mosquito that cannot be infected by the malaria parasite.
Genetically modified mosquitoes are far from ready for use in the field, but the researchers achieved an unprecedented 100 percent blockage of the Plasmodium parasite.
The team, led by entomologist Michael Riehle at the University of Arizona, created the mosquitoes by changing a single gene, one involved in the production of insulin. To test the effect, researchers injected 90 mosquitoes with the malaria parasite. Ten days later, at a point when normal mosquitoes would have bellies full of parasites, they didn’t find any.
This is the first instance of a genetic modification that completely blocked development of a malaria parasite that can infect humans. The research was reported online Thursday in the journal PLoS Pathogens.
“We were just hoping to see any reduction,” Riehle said. “We were pretty shocked that it was that great.”
For practical application, the modified gene would have to spread throughout the entire mosquito population. Normally, this would only occur if the gene provided a great evolutionary advantage, but these malaria-resistant genes don’t have that effect.
“It’s like a train,” said Mark Benedict, a medical entomologist and consultant for the Centers for Disease Control and Prevention. “You’ve got to have a car — that’s the gene — but you’ve got to have an engine as well.”
