US researchers said Monday they have created a strain of mosquitoes that carries a malaria-blocking gene in the laboratory, a major advance that may help ultimately eliminate the insects' ability to transmit the disease to humans.

Using a gene editing technique called CRISPR-Cas9, researchers from the University of California inserted the anti-malarial gene into the germ line of Anopheles stephensi mosquitoes, a leading malaria vector in Asia.

They found the gene, which codes for antibodies that combat the parasite, was inherited by almost 100 percent -- 99.5 percent, to be exact -- of the mosquito offspring.

"This opens up the real promise that this technique can be adapted for eliminating malaria," said study author Anthony James, professor of molecular biology & biochemistry and microbiology & molecular genetics at the University of California, Irvine.

He added that further testing will be needed to confirm the efficacy of the antibodies and that this could eventually lead to field studies.

"This is a significant first step," said James, a National Academy of Sciences member. "We know the gene works. The mosquitoes we created are not the final brand, but we know this technology allows us to efficiently create large populations."

Peter Atkinson, professor of genetics at the University of California, Riverside, who was not involved in the study, said the study is extremely interesting since it demonstrates that gene drive mediated by the Cas9-based system can be achieved in this important pest species in the laboratory.

"Should it prove to be translatable to field studies and should the effector gene being used prove to significantly reduce the capacity of the mosquito to carry the malaria vector, then it is quite possible that this technology would become an important tool in the control of malaria," Atkinson said. "As such it would constitute a very, very significant advance in the field."

Malaria is one of the world's leading health problems. More than 40 percent of the world's population live in areas where there is a risk of contracting the disease.

According to the US Centers for Disease Control and Prevention, 300 million to 500 million cases of malaria occur each year, and nearly 1 million people die of the disease annually -- largely infants, young children and pregnant women, most of them in Africa.

The findings were published in the US journal Proceedings of the National Academy of Sciences.