New research: Scientists engineer mosquitoes that can’t spread malaria, offer hope of eradicating disease

Subject: Science and Technology

Context-

Scientists have genetically modified mosquitoes to slow the growth of malaria-causing parasites in their guts — an advancement that can help prevent transmission of the disease to humans.
The disease is transmitted between people through a female mosquito after it bites someone infected with the malaria parasite.
The parasite develops into its next stage in the mosquito’s gut and travels to its salivary glands, ready to infect the next person it bites.
Now, the mosquitoes have been engineered to produce compounds that slow the growth of malaria-causing parasites.
Though only around 10 per cent of mosquitoes live long enough for the infectious parasite to develop, malaria remains one of the most devastating diseases globally, putting at risk about half of the world’s population.
In 2021, it infected 241 million people and killed 627,000 people.

The research-

Researchers from the Institute for Disease Modelling at the Bill and Melinda Gates Foundation developed a model to assess the impact of such modifications and found it could be effective even where transmission is high.
While the technique has been shown to dramatically reduce the possibility of malaria spreading in a lab setting, if proven in the real world it could offer a powerful new tool to help eliminate malaria.
Researchers from the Transmission: Zero team at Imperial College London, UK, genetically modified the main malaria-carrying species of mosquito in sub-Saharan Africa, Anopheles gambiae, such that the mosquito produced antimicrobial peptides in its gut when it had a blood meal.

How it works-

The peptides impair the malarial parasite’s development and also cause the mosquitoes to have a shorter life span.
Gene drive is one such powerful weapon that in combination with drugs, vaccines and mosquito control can help stop the spread of malaria and save human lives.
Gene drive would cause the anti-parasite genetic modification to be preferentially inherited, making it spread more widely among any natural population.

Applicability-

It would, however, require extremely careful planning to minimise risks before any field trials. The Transmission: Zero team is, therefore, creating two separate but compatible strains of modified mosquitoes — one with the anti-parasite modification and one with the gene drive.
They can then test the anti-parasite modification on its own first, adding in the gene drive once it has been shown to be effective.
With partners in Tanzania, the team set up a facility to conduct some first tests.
They are also risk-assessing potential releases of modified mosquitoes and taking into account potential hazards, but are hopeful that their intervention can help eradicate malaria.