Malaria-carrying mosquitoes could be bred out of existence using ‘gene drive’ technology


Researchers focused on one particular mosquito species, Anopheles Gambiae, known to cause malaria (Picture: Getty)

Malaria-carrying mosquitoes have been eliminated using ‘gene drive’ technology in a nature-like environment, in a world-first study.

By altering a gene that blocks female mosquito reproduction, and allowing that gene to spread, researchers found they could ensure complete mosquito population collapse within one year of the experiment’s start.

It’s the first time so-called ‘gene drive’ technology has been shown to be effective in challenging ecological conditions over a long time scale.

The results of the study, published in Nature Communications today, could be a key tool in battling the hundreds of millions of cases of malaria infections that happen each year.

‘The challenges facing malaria elimination have intensified in recent years, due in part to the spread of insecticide resistance and large gaps in funding for parts of sub-Saharan Africa,’ said co-lead author of the study Dr. Drew Hammond.

‘Sadly, researchers estimate that Covid-19 related disruptions may have doubled mortality from malaria in 2020, threatening a setback of several decades.

‘Gene drive is a self-sustaining and fast acting technology that can work alongside existing tools such as bed nets, insecticides and vaccines – and could be a game-changer in bringing about malaria elimination.’

Mosquitoes cause more than 400,000 deaths each year (Picture: Getty)

In 2019, there were 229 million cases of malaria and 409,000 deaths.

Of the 3,500 mosquito species worldwide, only a tiny fraction can carry malaria. The vast majority of malaria cases are caused by only a handful of species.

Researchers hope that by eliminating the small number of malaria-carrying mosquitos, they can help eradicate the disease entirely.

The team, comprised of researchers from Imperial College London, Liverpool School of Tropical Medicine and the Italian Polo GGB, targeted the mosquito species Anopheles Gambiae, which is responsible for the majority of malaria transmission in sub-Saharan Africa.

The mosquitoes were placed in cages simulating real-world conditions, an essential step suggested by the World Health Organisation before any release into nature.

Gene drive efforts have been viewed with suspicion by environmentalists after previous efforts to modify natural populations have ended in disaster from unintended consequences.

Cane toads, which were introduced in Australia in 1935 to control crop-eating beetles, soon overran natural populations and turned into an ecological disaster.

Researchers hope that by showing the efficacy and safety of gene drives in real-world simulations, the technology can be introduced to the natural world.

The technology will work alongside other tools like mosquito nets and drugs (Picture: Getty)

To simulate a natural environment, scientists used hundreds of mosquitoes of different ages, varied temperature and humidity, introduced natural landmarks and used specialised lighting to simulate sunrise and sunset.

This encouraged the mosquitoes to engage in the complex mating, resting, foraging and egg-laying behaviours that they perform in the real world.

The modified mosquitoes were then introduced at frequencies of 12.5% and 25% of the population, as researchers tracked how quickly the infertile element spread through the population.

Both percentages of infertile females reproduced frequently enough that there was complete population collapse within one year.

One potential problem with previous gene drives is natural mutations that become resistant to the technology – but in the year-long experiment, no new natural modifications were observed, which researchers suggest mean their ‘modification driving female infertility is robust’.

While the results are encouraging, scientists emphasise there are still many safety and efficacy issues to assess before the technology can be introduced to the wild.


MORE :
Mosquito ‘bacteria hack’ nearly eliminates dengue fever and could save millions of lives


MORE : Why do mosquitoes love human blood? Science just figured it out





READ SOURCE

See also  The 3 very best TV deals of Prime Day 2019 you can still get

LEAVE A REPLY

Please enter your comment!
Please enter your name here