Transgenic Mosquitoes: A New Approach to Preventing Malaria?

| October 20, 2011 | 0 Comments

The Anopheles mosquito, vector for malaria. Photo courtesy of the NIH (http://nih.gov)

Malaria is preventable and curable, yet, due to gaps in systematized prevention efforts, the disease accounts for 20% of childhood deaths in Africa. As a result, groups such as the World Health Organization (WHO) have targeted malaria through vertical vector control programs. WHO identifies these efforts as “the only intervention that can reduce malaria transmission from very high levels to close to zero”.

However, the success of top-down vector control efforts is limited because by nature they are often focused on one specific issue. One specific approach to vertical vector control that illustrates this is the bioengineering of genetically modified (GM) mosquitoes that carry immunity to the Plasmodium parasite. Most recently, scientists have engineered transgenic mosquitoes that express specific genes  to enhance immunity against the Plasmodium parasite. In controlled experiments, transgenic mosquitoes were shown to fixate in the mosquito population over due to increased fitness, therefore shrinking the population of non-immune mosquitoes over time.

While these results are promising, concerns have been raised regarding the biosafety and public awareness of vertical vector control programs. In the case of biosafety, the potential long-term environmental effects transgenic mosquitoes would have in a region have not yet been established due to the novelty of the bioengineering development. This in turn limits the clarity of communication between researchers attempting to conduct studies in malaria-ridden regions and the people who inhabit them.

A recent study published in the peer-reviewed Malaria Journal found that residents in an area of potential GM-mosquito release in Mali had limited knowledge of the bioengineering process. These residents voiced qualms about the safety of GM mosquitoes, which was not fully explained due to lack of terminology in their native language and lack of solid knowledge on the part of researchers.

Still, this study was conducted only in a potential area of GM mosquito release.  A more concrete instance of communication failure occurred after a trial of dengue fever-immune mosquitoes was conducted in Malaysia and the Cayman Islands. Oxitec, the company that carried out the trial, was criticized for its lack of communication of its intentions to the public. Many residents and even public health officials complained that they did not hear of the experiments until after Oxitec announced their findings.

These sorts of communication problems raise ethical concerns for a potential release of transgenic mosquitoes in a high-risk area such as Africa. Citizens in the area deserve to exercise the right to give consent before such a release occurs, especially when the long-term effects of these mosquitoes are not fully understood. The nature of mosquitoes traveling from community to community means that it is impossible to guarantee that all citizens have this sort of input before they are impacted by the GM mosquitoes.

In these cases, although the mosquitoes are the direct objects of study, cohabiting human subjects in the areas of release are also directly affected and deserving of attention. Through the integration of top-down vector control programs and improvement of health systems, a management system can be devised that involves both respectful decision-making with local populations and effective solutions for malaria prevention and care.

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Category: Online, Technology

About the Author ()

Audrey Zhang '15 is the webmaster for HCGHR and a Technology and Global Health online columnist. She is a resident of Adams House concentrating in History of Science with a focus on Medicine and Society, and a secondary field in Global Health and Health Policy. In her spare time, she enjoys competitive reading and Tazo tea.

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