A genetically modified (GM) male mosquito which is successfully being used in countries abroad in the fight against dengue fever that affects up to 100 million people worldwide, could be on the cards for T&T. Admitting last Wednesday that there were 1,639 suspected cases of dengue fever up to July 30, 2011, and one confirmed death, Health Minister Dr Fuad Khan said if the pilot studies of the GM mosquitoes have been proven successful in other countries, he saw no problem with "it being introduced here." Khan said he would have his ministry investigate the GM mosquito, which was developed by British biotechnology company Oxitec, but could not say within what time frame it was likely to be introduced in T&T.
"We would first have to look at it." The GM mosquito carries an artificial fragment of DNA designed to cause wild females with whom they mate to produce offspring that die at the pupa stage. This significantly reduces the spread of dengue and its native population below the numbers required to sustain dengue fever, transmitted through the bites of females. There is no vaccine or effective drug to treat dengue fever, which is a growing problem.
Combating dengue with test trials
Oxitec first commenced the Cayman trials in September 2009. Together with the islands' Mosquito Research and Control Unit, the company liberated 3.3 million sterile aedes aegypti mosquitoes into a region spanning 16 hectares. This exercise decreased the country's mosquito population by 80 per cent. Also, near the town of Bentong in Malaysia, a field experiment was conducted, releasing 6,000 mosquitoes into an uninhabited forest to monitor its dispersal between December, 2010 and January, 2011.
Malaysia had reported a 52 per cent increase in dengue-related deaths over the past 20 years. Total infections rose 11 per cent from 2009 to 50,000 cases last year, including 134 deaths. With its growing cases, Malaysia's government conducted an independent review of these semi-field trials and recommended that the project proceed to the next step once it passed regulatory and ethical clearances. In January, South-east Asia, as part of an ambitious attempt to combat dengue fever, also undertook a test run of development.
Mosquito eggs in demand
As Oxitec moves closer to commercial sales, additional capacity is under construction to prepare for the next phase in mass rearing its engineered sterile mosquitoes. With additional field trials already under way in Malaysia and Brazil, Oxitec is preparing to meet demands of between ten and 20 million mosquito eggs per week. In the short to medium term, this increased capacity will meet demand not only from trials but also from initial commercial sales in other territories.
Oxitec's next phase will focus on regional hubs. According to a March, 2009 World Health Organisation (WHO) bulletin on the Web site www.scielosp.org, it stated that there are approximately 25,000 dengue fatalities each year and severe cases require hospitalisation. A study conducted by the Indian Institute of Management in Ahmedabad, aedes mosquito-borne disease, primarily dengue fever, costs India a hefty US$1.3 billion every year, 95 per cent of that due to illness.
An expensive disease
WHO described dengue as an extremely expensive disease, estimated to cost the global economy over $5 billion per year. Though Oxitec has been breaking new ground in mosquito research, few believe they represent a silver bullet against mosquito-borne diseases. Concerns were expressed by environmental groups such as Ottawa-based ETC Group and EcoNexus of Oxford, of Oxitec releasing an entirely new strain of organism into the environment since this might not only create an empty niche which also affects organisms higher in the food chain that rely on mosquitoes as a dietary source.
Luke Alphey, founder and research director of Oxitec, who described progress towards the first field trials of GM mosquitoes said, "If the funds are made available, I can see the elimination of dengue from regions or groups of countries using GM technology integrated with other tools."