Science & Technology
Pest control
The UK-based company 'Oxitec' focuses on methods to control major global insect pests threatening public health and agriculture. Oxitec's proprietary technology is a genetic version of the 'sterile insect technique' (SIT), where sterile males are released into the environment to mate with wild-type females. Those matings produce no offspring, thus repeated release of large numbers of sterile males leads to a decline of the entire population.
While conventional SIT relies on radiation or chemical sterilization, 'Oxitec's' technology is environment-friendly as it uses the Tet Technology to generate insects carrying a conditional dominant lethal system. Last year, 'Oxitec' reported the results of a field trial on Grand Cayman involving Aedes aegypti the mosquito which spreads dengue fever. Dengue fever causes mild flu-like symptoms which sometimes develop into hemorrhagic fever which, unless treated promptly, may lead to shock and death. According to the World Health Organization about 2.5 billion people are at risk of Dengue fever and currently there is neither a specific medication nor a vaccine available. The only way to control the disease is to control the transmitting mosquito. In this particular study 'Oxitec' developed a strain of Aedes aegypti that is homozygous for a lethal gene and conditionally sterile. The gene modified mosquitos can be raised in large numbers in the laboratory but after their release, in a Doxycycline-free environment they compete with wild-type males for females. Offsprings of such matings cannot survive early developmental stages resulting in an overall decline of the population. In the Cayman Island trial the local Aedes population declined by 80% three months after the start of release of modified male mosquitoes. This first application of 'Oxitec's' proprietary technology which comprises the Tet System in an open field trial gives hope that this approach can be applied in other countries to control Dengue fever and eventually may also provide a means to combat other mosquito-borne diseases.