Sir

Your News story 'Sterile mosquitoes near take-off' (Nature 453, 435; 2008) discusses the likely release of genetically engineered mosquitoes to help contain dengue fever. It demonstrates just how close we are to a radically new set of strategies for managing a whole range of diseases and wildlife using genetically modified organisms (GMOs). But after assessing the risks and benefits, nations may reach different conclusions about their use. And that's quite a problem, considering that genetically modified bugs won't recognize national borders.

Malaysia may successfully avoid spreading the sterile mosquitoes across the border, and even if they do cross, any transgression will be limited to a single lifespan. Strategies that rely on genetically modifying mosquitoes that can still reproduce, such as those that you mention are being engineered by Austin Burt's team for malaria control, are more likely to have lingering effects as they spread among wild populations across national borders.

Although everyone would agree that diseases are bad, nations may have very different views about how they should be prevented. Effective control of mosquito-borne disease will not be achieved without regionally coordinated programmes, so a robust framework is needed to accommodate the differences (B. G. J. Knols et al. Am. J. Trop. Med. Hyg. 77, 232–242; 2007).

Nations have a right to decide the technological risks to which they expose themselves. The factors in decision-making here will not be only the simple ones of uncontested science — this is politics, and appropriately so. The potential for conflict over self-dispersing GMOs demands the attention of international law.

Unfortunately, that law is deficient. The most relevant treaty is the Convention on Biological Diversity and its instrument, the Cartagena Protocol on Biosafety. The protocol includes Malaysia and most of its neighbours — Thailand, Indonesia, Cambodia and Vietnam — but not Singapore or Australia. It falls far short of the proactive and instructive approach necessary for the deployment of GMOs designed to be self-dispersing and reproducing in the wild.

The world needs to get involved. Discussions should be formalized, ideally under the biodiversity convention, and widely accessible (for example, through the convention's Biosafety Clearing House). This trial would set the tone for future negotiations over this very new kind of biotechnology.