The global rise in the prevalence of mosquito-borne disease over recent decades has been well-charted, and the Indian sub-continent has suffered as much as anywhere. In India alone, the case numbers are staggering: every year almost 5.8 million people are estimated to suffer from dengue, just one of the devastating diseases transmitted by the Aedes aegypti mosquito. These diseases are also taking a toll on the Indian economy. Recent published work estimated that including lost productivity, the total financial cost of dengue to India is over $1 billion per year.
Dengue is not the only danger posed by Aedes aegypti: the same mosquito has been responsible for recent chikungunya outbreaks in the country, and it is also the primary carrier of the Zika virus, which was declared a Public Health Emergency of International Concern by the World Health Organisation (WHO) in February 2016. According to the WHO, the best way to prevent the spread of these diseases is to control the mosquito that transmits them.
Delivering a solution
Conventional methods of insect control for many public health pests have not changed significantly over many decades and often still depend upon insecticidal treatments which often carry toxins and are indiscriminate killers of insects including beneficial ones. Such strategies can be difficult, expensive, and increasingly less effective as mosquitoes develop resistance to these insecticides.
Through pioneering science incorporating advanced genetics, Oxitec has developed an innovative new solution to controlling the Aedes aegypti mosquito. Oxitec has used genetic engineering to create self-limiting male Aedes aegypti that are released to seek out and mate with wild females. They pass on a gene to their offspring that prevents them from surviving to adulthood, and this results in a decrease in the population. The released males also die within days resulting in an approach that does not persist in the environment.
During trials in Brazil, Panama and the Cayman Islands, releases of Oxitec’s mosquitoes have reduced the wild population of Aedes aegypti by more than 90% – an unparalleled level of control. This targeted species-specific approach may also reduce the need for insecticides, allowing more beneficial predators and native insects to flourish.
Oxitec has conducted extensive research on the self-limiting mosquito since it was first developed in 2002, and peer-reviewed articles can be found on our publications page.
Progress so far
A collaboration with our Indian partner, Gangabishan Bhikulal Investment and Trading Limited (GBIT), was established in 2011. Since then, laboratory work to evaluate Oxitec Aedes aegypti against local strains from Delhi and Aurangabad has been underway and results have been published:
Patil et al. (2014). Mating competitiveness and life-table comparisons between transgenic and Indian wild-type Aedes aegypti L. Pest Management Science, DOI 10.1002/ps.3873.
Following the positive laboratory assessment previously described, we are now ready to conduct the next stage of evaluation under natural environmental conditions.
Progress towards evaluations outside laboratory conditions will only be possible following approvals by the Indian regulatory bodies: the Review Committee on Genetic Manipulation (RCGM) and the Genetic Engineering Approval Committee (GEAC). An application to do so is presently under review.
Are you planning to introduce this mosquito in India?
India is heavily burdened by dengue as existing vector control strategies are not effective. Oxitec is working with GBIT, a privately held Indian company that specialises in developing and commercialising novel technologies in health and agriculture, with a view to introduce this technology for vector control in India. If approved for use by the regulators, the wider uptake of this technology as a management tool for controlling the Aedes aegypti mosquito has the potential to offer tremendous advantages in India.
Have you approached Indian authorities for regulatory approvals?
Yes, permission from the Review Committee for Genetic Manipulation (RCGM) for contained laboratory based studies was received by GBIT in September 2011. The results were published in a scientific journal, and we would like to proceed to the next stage of a larger evaluation. Permission for this was sought in October 2013 via RCGM.
When do you expect to start trials of this mosquito in India?
Field based studies will only begin following appraisal and approval by the relevant national biosafety committees (RCGM and/or GEAC). An application to conduct field trials is presently under review.
Will you be talking with the local community before a field trial begins?
Yes – Oxitec takes public engagement very seriously, and it is an important part of our work in every country in which we conduct projects. In India, we will carry out engagement activities with the local community before any field trial starts and will continue to discuss the project and its results with the community as it progresses.
What are your overall plans for the Indian market?
With our partner GBIT, we aim to make the technology available to public health authorities in India and the wider region to help suppress Aedes aegypti mosquitoes that spread devastating diseases.
How can I find out more?
Frequently asked questions: www.oxitec.com/faqs
Phone: +44 (0) 1235 832 393
GBIT website: http://gbitindia.com