Can genetically modified mosquitos help wipe out malaria?

Despite a 60 percent global reduction in deaths due to malaria, experts still predict the mosquito-borne illness, present in 97 countries and territories, will infect 214 million people worldwide and claim the lives of 438,000 this year. Two-thirds of its victims are generally children under the age of 5, according toWorld Health Organization statistics. And a malaria strain in Cambodia and Thailand has become resistant to multiple drugs, a problem experts fear could spread to other regions and pose dire consequences for public health.

But the new gene editing technique, CRISPR-Cas9, may offer a drug-free way for researchers to prevent malaria. Scientists at the University of California in Irvine (UCI) inserted a gene into the germ line of Anopheles stephensi mosquitos, the type that carries the disease. The gene produces antibodies to fight malaria and, because researchers insert it into the mosquitoes’ DNA, it becomes an inherited trait. The researchers found the gene was transmitted to 99.5 percent of the genetically modified mosquitoes’ offspring.

Ultimately, the researchers toldFox News, they plan to release genetically modified mosquitoes to mate with wild mosquitoes so that their malaria-blocking genes enter the gene pool and eventually overtake the population, rendering them unable to infect people.

The genetic modification can spread rapidly through a mosquito population, “increasing from 1 percent to more than 99 percent in 10 generations, or about one season for mosquitoes,” said Valentino Gantz, a biologist at the University of California-San Diego.

Former researchers have sought ways to simply wipe out mosquitoes altogether. In the short-term, DDT-based insecticides were effective, but with time mosquito populations actually became stronger because they built up resistance to the insecticide.

Then scientists turned to genetic engineering as a way to eradicate mosquitoes. In earlier studies, the UCI researchers created mosquitoes in which females, which carry dengue fever, were unable to fly. The males, which do not carry the illness, could pass the modified gene on to their offspring.

“The crippled females will die where they hatch and you’ve got yourself a mutant force of GM males ready to start their work,” the researchers told

Gizmag. The scientists found that a sufficient number of genetically modified male mosquitoes could wipe out a mosquito population within a few months.

Other researchers have proposed decimating mosquito populations by genetically engineering them to produce nearly all male offspring.

While totally eradicating the blood-thirsty, annoying insects sounds appealing, some experts have voiced concerns about the ecological consequences. They warn of unintended ramifications, such as disrupting the food chain for the many birds and fish that eat mosquitoes, upsetting the balance of nature to make way for even nastier pests, or eliminating a means of pollination for certain plants.

The new gene-editing technique does not involve these potential risks.

“In contrast, our much more flexible system only prevents mosquitoes from carrying malaria but can be used to do no harm to the mosquito. So it should generate the least amount of ecological damage,” Ethan Bier, a biologist at the University of California-San Diego, told Fox News.

According to Anthony James, a UCI molecular biologist, gene modification alone will not wipe out malaria, but in conjunction with treatment and preventive drugs, future vaccines, mosquito-blocking bed nets, and eradication of mosquito-breeding sites, it could help eliminate the disease.