Malaria, dengue, chikungunya –deadly diseases from which billions are at risk. Spread by insects such as mosquitoes, attempts to control these diseases usually involve targeting the insect host – using techniques ranging from insecticides to oil spills. But a new approach to controlling insect numbers is being developed, and it revolves around genetically modified, sterile insects.

British-based Oxitec is the current leader in developing this technology, with applications in both public health and agriculture.

The general process used in each of Oxitec’s genetically modified insects is similar, involving the introduction of sterility or sterility-equivalent traits into the wild population. Generally the insects will grow normally in the presence of a chemical (such as tetracycline), which is then not required for adult survival. Upon release into the environment they mate with wild-type insects, with the offspring then showing either late-stage lethality or developmental problems (such as an inability to fly) which effectively remove them from the gene pool. This method thus acts differently to insecticides, which kill the current population, by instead acting to remove the next generation.Oxitec’s flagship product is the modified Aedes aegypti sterile mosquito, which has been targeted as it is the primary vector by which dengue and chikungunya are spread, allowing for targeted intervention. Furthermore only the females of the species are involved in spreading disease, allowing Oxitec to release large numbers of male mosquitoes without fear of increasing disease transmission. Oxitec is currently running several field trials in Brazil and Panama to determine the efficacy of their approach – with impressive results so far, suppressing wild populations by up to 80%.Beyond this, Oxitec have begun commercial trials with a modified Pink Bollworm, with further modified insect strains in development including the Diamondback moth, Mediterranean and Mexican fruit flies, Olive fly, and Aedes albopictus. Their general success in the agricultural field lags behind that of public health – not through any fault of efficacy but rather due to regulatory and political barriers involved in the deliberate release of genetic modifications into the wild population. These barriers lay in part behind the eventual rejection of Oxitec’s attempt to trial their insects after a multi-year application process, according to recent evidence provided to the UK House of Lords report on the matter.However, despite these setbacks, Oxitec is forging ahead with their agricultural products. They recently announced that Western Australia’s Department of Agriculture and Food would soon begin (indoor) trials of the GM Mediterranean fruit fly. This builds upon experience already gained through successful trials of the A. aegypti system and may act to boost the uptake of their technology. Although widespread adoption within the EU is difficult due to widespread regulatory complexity, there remain a number of other countries with both significant agricultural industries and more consistent approaches to genetic modification.The potential for success inherent in Oxitec can be seen in their acquisition by Intrexon earlier this year for $160 million USD. Intrexon, of course, are one of the largest synthetic biology companies in the world with a market cap of 43.6 billion USD and subsidiaries in fields ranging from non-browning apples to genetically engineered salmon. The acquisition can be seen as a large vote of faith in Oxitec’s progress so far and their potential to create significant returns.Will Oxitec realise those goals? Come along to the upcoming SynBioBeta London 2016 conference to hear a bit more about their plans for the future.