An end to malaria? Scientists find a way to suppress mosquitoes carrying deadly parasite

US scientists are hailing a new gene modification technique that leads to the suppression of female mosquitoes of the species that most commonly spreads the deadly malaria parasite.

They say the technique is a “safe, controllable and scalable solution the world urgently needs to eliminate malaria”.

There are about seven types of African malaria mosquitoes that belong to the complex Anopheles gambiae and account for about 250 million cases of malaria each year.

Bed netting and insecticides are traditional methods used to prevent the transmission of the disease, however these are increasingly ineffective.

Now a team at the University of California San Diego has developed a new technology to genetically suppress the females of these populations, which are the vectors of malaria spread. Their research is published today in Science Advances.

Using CRISPR technology, they can disrupt the ‘femaleless’ gene fle, preventing the development of female offspring. This system, now dubbed Ifegenia, was tested in the lab by crossing two families of genetically modified mosquitoes – one which carries the ‘scissors’ gene Cas9, and another which carries the RNA molecule that targets the fle gene.

“We crossed them together and in the offspring it killed all the female mosquitoes,” says study lead Andrea Smidler from UC San Diego.

Male mosquitoes are unaffected by the modified genes, instead spreading Ifegenia among other living females and modifying the sex of future offspring.

Similar gene modification has been touted as a management solution for other pest species, including mosquitoes that spread diseases like dengue and yellow fever. In Australia, similar methods have been suggested for the management of introduced predators like cats and foxes, and pests like mice.

However the use of such technology raises ethical questions around their use, something the study’s senior author Omar Akbari says is a hurdle to overcome before such technology is rolled-out at scale.

“This technology has the potential to be the safe, controllable and scalable solution the world urgently needs to eliminate malaria once and for all,” Professor Akbari says.

“We need to transition our efforts to seek social acceptance, regulatory use authorizations and funding opportunities to put this system to its ultimate test of suppressing wild malaria-transmitting mosquito populations.”