GM mosquito trial results in Cayman prove ineffective in tackling dengueselfnews Post This poor quality paper pours cold water on the idea that Oxitecs GM mosquitoes will be an effective way to tackle dengue said Dr Helen Wallace, Director of GeneWatch UK. Staff would be better employed using the well-established public health approach of removing mosquito breeding sites rather than in placing GM mosquito pupae at intervals across a site. Removing the flower pots and water containers where mosquitoes breed has the added benefit of reducing both mosquito species that spread dengue, not just one of them. It is hard to see how Oxitec can justify commercial releases of its GM mosquitoes based on such poor data. During the experiments, Oxitec increased releases of GM male mosquitoes from the expected 3,150 males per hectare per week to about 14,000. When local residents complained about the nuisance caused by the very large number of mosquitoes, Oxitec halved the number of adults released and deployed GM pupae at the site (2). Oxitec reports several different estimates of the reduction in the wild population of mosquitoes, ranging from 60 per cent to 85 per cent depending what comparisons are made. Because there is no baseline data on mosquito populations at the site there is considerable uncertainty in the results. At different times, Oxitec moved mosquito traps from one location to another and changed the size of the release site, adding to difficulties in interpreting the results. Releasing such large numbers of mosquitoes adds to concerns that the small percentage of surviving GM mosquito offspring and accidental releases of GM female mosquitoes could pose unnecessary risks (3). Oxitecs failure to publish and consult on a risk assessment and obtain informed consent from Cayman Islands residents before going ahead with its experiments remains unacceptable. Oxitecs summary of the necessary regulatory requirements is misleading because it fails to mention that it should have sent a risk assessment which meets European standards to the EU and UK authorities before exporting GM mosquito eggs to the Cayman Islands (4). Informed consent to such experiments is not possible unless public information on the risks has been made available. Plans to scale-up releases of GM mosquitoes in dengue-endemic Brazil should be halted whilst the implications of these poor results are thoroughly considered said Dr Wallace. Authorities in other places where releases have been planned, such as Florida and Panama, should also stop and think again. For further information contact: Dr Helen Wallace: 01298-24300 (office); 07903-311584 (mobile). Notes for Editors: (1) Harris et al. (2012) Successful suppression of a field mosquito population by sustained release of engineered male mosquitoes. Correspondence to Nature Biotechnology. (2) The only consistent project-related criticism from the community related to nuisance from the large numbers of males in each individual release in the first part of Period 3. In response we promptly reduced these numbers and moved the release points further from habitations. We also partly substituted with pupal releases, from which adults emerge over a period of time. Following these changes, no further adverse comments were received. Supplementary material to (1). (3) Reeves RG et al. (2012) Scientific Standards and the Regulation of Genetically Modified Insects. Lehane MJ, ed. PLoS Neglected Tropical Diseases, 6(1), p.e1502. (4) Oxitecs Genetically Modified Mosquitoes: Ongoing Concerns. GeneWatch UK briefing. August 2012. On: http://www.genewatch.org/uploads/f03c6d66a9b354535738483c1c3d49e4/Oxitec_unansweredQs_fin.pdf You can read other articles by selfnews Post HERE linkwithin_text=Related Articles: 