Could Genetically Modified Mosquitoes Stop the Spread of Deadly Diseases?

Recent data from a trial using genetically modified mosquitoes to reduce their population adds to the growing evidence that this could be a powerful strategy in the future to stop mosquito-borne diseases.

Source: Pixabay

Over six months in 2018-9, 500 genetically modified (GM) mosquitoes were released into four populous areas of São Paulo, Brazil in an attempt to bring down the mosquito population. The hope is to eventually use this strategy to eradicate the spread of dengue virus in the regions. For over 70 years, numerous projects have been set up all over the globe to investigate whether these GM mosquitoes could help in eliminating different mosquito-borne diseases, like malaria and dengue. Putting an end to the spread of these diseases is currently far from reality; but the recent data from the Sao Paulo study may bring us one step closer. 

Initiated by a group of researchers at Oxitec, a UK-based biotechnology company, GM male mosquitoes were engineered with the addition of a gene called OX5034 in their genomes. When OX5034 is passed on to the female offspring of these mosquitoes, it stops the female offspring from growing into adulthood by causing premature death. As diseases are only transmitted via the female mosquitoes, the theory was that by lessening the population of females, mosquito-borne diseases were less likely to be transmitted. 

As predicted, over a single mating season of six months, the data displayed a drastic decrease, between 88-96%, of mosquito population in the city of Indaiatuba, São Paulo. This was a great success that aligned with results from previous studies done using other mating-based approaches to population reduction. This, however, will not result in a permanent reduction of the population - the modification was designed to phase out over multiple generations so as to not cause any irreversible changes to the mosquito species. In addition to this, although the study came out a success in declining the mosquitoes population, it didn’t directly investigate whether there was any significant impact on dengue disease incidences in the area; subsequent study is therefore needed to further investigate this potential link to the transmission of mosquito-borne diseases.

Although the response to the results of this study have been overwhelmingly positive, there remains the question of how using these insects may be regulated and employed globally in the future. As stated by the CDC, GM mosquitoes aren’t considered to have any potential risks to humans, animals, or the environment. However, as reassuring as the statement may sound, nothing is always safe, especially with new technologies like GM organisms. What are the possible side effects GM mosquitoes may cause to the wider ecosystem? Without the sufficient experimental trials, the answers to these questions are still unsure. One sure thing this study has shown, however, is that GM mosquitoes are on their way to becoming an innovative new step in eradicating mosquito-borne diseases like dengue and improving the lives of those living in at-risk areas.