Test-trials may prevent mosquitoes from spreading disease and prevent 1 million deaths each year.
BY EMILY HERZSTEIN
3500 species of mosquitoes are known, but only females from a 100 species that draw blood from humans to develop their eggs carry parasites can cause human disease. Most commonly these diseases are malaria, dengue, yellow fever and more recently zika. Infecting A. aegypti with Wolbachia, a bacterium that does not infect mosquitoes naturally and cannot infect humans, could mean mosquitoes cannot pick up and transmit viruses easily. The bacteria are passed on through eggs, sustaining itself in environment and gives ongoing protection. Small tests near Cairns and in Vietnam and Indonesia showed 90% mosquitoes were affected in weeks and are now being tested on large-scale field trials.
Wolbachia is safe for humans, animals and the environment as it is already found in many insect species. Two independent risk assessments gave an overall risk rating of ‘negligible’ for the release of Wolbachia-infected mosquitoes. The eliminate dengue program is not trying to reduce the overall number of mosquitoes, but to reduce the ability to transmit disease, thus safeguarding its niche in the ecosystem. For large urban environment targeting has a very affordable cost of US$1 per person. This method is now recommended by the WHO.
Currently, Vector control is a highly cost-effective way to prevent malaria at us$2.20 per person per year with insecticide-treated nets. Still, the WHO recommends testing new approaches for elimination, focusing on breeding sites and integrated approaches that tackle all life stages. Scientists claim that if the niche is replaced by another insect the ecological influence of elimination would not be bad, there would only be collateral damage.
Furthermore, the discovery of female attraction to body odour can help develop more competent repellents.
In order to save millions of lives; research has been done. The method with the most social support, least risk, ecologically friendly, self-sustainable, cheap and least dangerous in terms of the unknown effects of spreading GM animals in the wild appears currently to be that of Wolbachia bacteria. This method should be deployed together with vector control in the form of better repellents and other forms of vector control to ensure the lowest amount of mosquito-borne diseases as possible without eliminating mosquitoes.
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