Malaria-carrying mosquitoes wiped out in lab with genetic method that creates male-only offspring

Scientists have modified mosquitoes to produce sperm that will only create males, pioneering a fresh approach to eradicating malaria.

In a study published in the journal Nature Communications, scientists from Imperial College London have tested a new genetic method that distorts the sex ratio of Anopheles gambiae mosquitoes, the main transmitters of the malaria parasite, so that the female mosquitoes that bite and pass the disease to humans are no longer produced.

In the first laboratory tests, the method created a fully fertile mosquito strain that produced 95 per cent male offspring.

The scientists introduced the genetically modified mosquitoes to five caged wild-type mosquito populations. In four of the five cages, this eliminated the entire population within six generations, because of the lack of females. The hope is that if this could be replicated in the wild, this would ultimately cause the malaria-carrying mosquito population to crash.

This is the first time that scientists have been able to manipulate the sex ratios of mosquito populations. The researchers believe the work paves the way for a pioneering approach to controlling malaria.

Since 2000, increased prevention and control measures have reduced global malaria mortality rates by 42 per cent, but the disease remains a prevalent killer especially in vulnerable sub-Saharan African regions. Malaria control has also been threatened by the spread of insecticide resistant mosquitoes and malaria parasites resistant to drugs. According to latest estimates by the World Health Organization, over 3.4 billion people are at risk from contracting malaria and an estimated 627,000 people die each year from the disease.