Behind an unmarked door at the side of an anonymous second world war Nissen hut in the middle of Oxfordshire, a group of scientists are attending to the needs of hundreds of thousands of mosquitoes. They provide horse blood for the females to feed on, moist beds for them to lay their eggs, and add genes that transform the mosquitoes into what could be the most decisive tool yet invented to combat mosquito-borne disease.
The mosquitoes developed and raised here at the laboratories of Oxitec, a British biotech company based near Didcot, have already infiltrated wild populations in Brazil, Malaysia and the Cayman Islands, and will soon be unleashed in Panama and India. The company hopes that it will reduce populations of disease-carrying mosquitoes by 80% but public opposition to anything “genetically modified” remains a significant obstacle to the possibility of saving thousands of lives.
Mosquito-borne diseases are one of the major barriers preventing economic progress in the developing world. According to the World Health Organisation, 200 million people were victims of malaria in 2010 and 655,000, mostly children, died from it. Dengue fever is believed to affect 50-100 million people per year and results in around 20,000 deaths.
“From a scientific point of view and an environmental sustainability point of view, we think we have a really good solution to the problem,” says Hadyn Parry, the CEO of Oxitec.
Unlike GM crops, Oxitec’s mosquitoes are not designed to spread their genes down the line or to other species. “We are not putting an advantage into these mosquitoes; we are putting in a disadvantage, sterility, which is the biggest disadvantage you can have,” says Parry. “You are not spreading your gene down generations because each one is sterile – it dies out. They do not out cross and mate with other species. So you are not spreading your gene laterally or downward.”
Critics of Oxitec say that the company is rushing to commercialise its products to provide a return on investment, massaging research while leaving key questions unanswered. Dr Helen Wallace, the director of GeneWatch, says she has several problems with Oxitec’s findings from its trials. One major issue, she says, is the occurrence of the tetracycline – the antibiotic that the young mosquitoes need to survive – in livestock and meat. Theoretically, if a female mosquito, daughter to a modified one, bit meat or an animal that contained tetracycline, she could survive. Oxitec says that the chance of this happening is very slim and in its most recent trial in the Caymans, it did not find a single mosquito that had survived.