UK biotech firm Oxitec has developed a strain of the Aedes aegypti mosquito genetically engineered to produce offspring which die prematurely. The company has so far released large numbers of these mosquitoes in Brazil, the Cayman Islands and Malaysia under experiments aimed at reducing the adult population of Aedes aegypti, which is responsible for transmitting the tropical disease dengue fever.
Even as Oxitec continues to promote its patented technology, Genetically Modified Mosquitoes: Ongoing Concerns points to a host of concerns and unanswered questions surrounding the use of the genetically modified (GM) Aedes aegypti as a form of mosquito control. The technology may not be particularly effective in suppressing mosquito populations and may even, especially in cases of limited efficacy, worsen the dengue problem. There is also uncertainty over the extent to which some of the GM mosquitoes' offspring do survive into adulthood. More generally, the potential adverse effects of this technology are still not fully understood, given the complex interactions in the ecosystem between Aedes aegypti, other mosquito species, the viruses they carry and the humans they bite.
These concerns were not properly addressed prior to the mosquito open release trials, for which the risk assessment and consultation process has been seriously inadequate. Without a thorough examination of the risks and benefits, it is questionable whether the objectives of mosquito and dengue control would be best served by deploying Oxitec's GM mosquitoes.
Chapter 1. Introduction
Chapter 2. Will releasing GM mosquitoes suppress wild mosquito populations?
Chapter 3. Will population suppression reduce dengue fever?
Chapter 4. Impacts of the antibiotic tetracycline
Chapter 5. Impacts of population changes on other mosquito species
Chapter 6. Introduction of new mosquito strains and transmission of other diseases
Chapter 7. Could resistance develop so that more GM mosquitoes survive and breed, or fitness of the GM mosquitoes is reduced over time?
Chapter 8. Compatibility with traditional control methods
Chapter 9. Will people be bitten by GM mosquitoes, or will they harm other organisms?
Chapter 10. Traceability and monitoring
Chapter 11. Assessing the potential impacts of releases on a complex system
Chapter 12. Regulation, consent and transboundary movements
Chapter 13. Alternatives
Chapter 14. Conclusions
Helen Wallace is Director of GeneWatch UK, a not-for-profit organisation which aims to ensure genetic science and technology is used in the public interest. She has worked as a scientist and campaigner in the academic, private and NGO sectors. Her scientific background is in computer modelling of complex environmental systems.