GENETICALLY MODIFIED MOSQUITOES REDUCE DENGUE RISK
Since it returned to mainstream life in a big way recently, Dengue has grabbed interest all over the world, and efforts to control it have been renewed. In this article, we tell you about a rather left-field idea to control mosquito populations: by using a genetically modified mosquito.
Dengue fever is so excruciating that it is often called the ‘bone breaker’. It causes severe pain to joints and abdomen, causing vomiting and circulatory system failure as well. It is nearly impossible to treat, so the only way to control it is by reducing the number of mosquitoes that carry it.
One of the more radical approaches to controlling mosquito population is to genetically modify them so that their offspring will not survive. A year-long trial in Brazil with GM mosquitoes has been the most successful one yet, reducing the population of the disease-carrying pests by 95%, according to a study published recently.
Oxitec, a British biotech company, has engineered a male mosquito that looks like just another mosquito to a female, but carries a mutation that kills the off-spring before they’re able to reproduce or transmit the disease. The testing of this process happened in Juazeiro, a city in northeast Brazil, where dengue had been wiped out for twenty years, but has returned with a vengeance in recent times, affecting as many as 16 million people every year.
The neighbourhood in which the researchers tested the modified mosquitoes was a low-income area with high rates of dengue infection, according to local public health officials. Over a one-year period, the researchers released the modified males into the local environment and monitored the resulting eggs, looking for a characteristic fluorescent marker engineered into the males’ genome. In the course of that year, the number of disease-carrying mosquitoes decreased by 95 percent as compared to a control group in a neighbourhood next door.
Oxitec is involved in similar such innovative methods for controlling disease-carrying mosquitoes. Researchers hope to scale up their efforts in the future in the hope of eradicating dengue over larger areas.
This could also be the first step in using genetic modification as a method to control pests of all kinds – like rats and other lower animals that have for years proven hard to control. However, these methods ought to be used in moderation and with care, because they have the potential – if unchecked – to wipe out entire species of animals and upset the biological balance of the planet.