War against mosquitoes transmitting Zika attracts applause, controversy

Few companies have received as much attention in recent weeks as Oxitec, a British biotechnology company that breeds genetically modified (GM) insects to combat the spread of diseases such as dengue and the Zika virus.

Oxitec releases GM male mosquitoes with a self-limiting gene, essentially rendering them sterile and causing any offspring to die before they reach adulthood, XInhua reported.

In trials around the world, including the Brazilian city of Piracicaba, Oxitec claims to have wiped out over 90 percent of the Aedes aegypti mosquito.

Given that this pesky critter is the main carrier and transmitter of Zika, chikungunya and dengue, this has led to a spike in interest in Oxitec's methods.

Hadyn Parry, CEO of Oxitec, said: "Our mosquitoes do not impact the disease; we just reduce the number of mosquitoes. You get Zika, dengue or chikungunya by being bitten by a mosquito carrying that disease. No mosquito means no disease, less mosquitoes means less disease," he said.

Both the US and Brazil confirmed that the Zika virus had been propagated by sexual transmission and blood transfusion.

According to the US Centres for Disease Control and Prevention, the Zika virus only remains in the bloodstream for a few weeks, meaning that eradicating mosquito populations would remove the threat of other types of transmission.

Despite this seemingly positive impact, the rollout of Oxitec's GM mosquitoes in Latin America to date has been limited. The city of Piracicaba, in the Brazilian state of Sao Paulo, which saw a trial release of Oxitec's mosquitoes in 2015, is expanding the project to cover about 60,000 people.

According to statistics provided by Oxitec, the city saw 133 cases of dengue in 2014 and the beginning of 2015. This was cut down to just one for the rest of 2015 after the Oxitec trial began.

However, the release of further Oxitec GM mosquitoes across the country faces a major obstacle. While Brazil's regulator for GM organisms has stated Oxitec's product poses no risk, final approval is needed by the Health Ministry before commercialisation can begin.

"But to market and sell our product, we need an authorisation from the Ministry of Health. We think we are very close to getting that authorisation," said Parry.

That decision would not just impact Oxitec's operations in Brazil but would determine if and when its GM mosquitoes could be released in other countries.

"Once Brazil approves us, I do not think we will see a similar time frame in other Latin American countries," the executive said.

"This mosquito is the same species all around the world, our product is exactly the same, and a lot of Latin American cities are very similar."

However, should a country decide that certain differentiating factors warrant extra processes, Oxitec said it will be happy to carry out extra studies.

Parry said many countries and private companies are collaborating to develop a vaccine but such a solution may be slow.

A final hurdle for Oxitec has been the controversies that have grown around their methods. A cursory search on the internet turns up a number of articles, questioning or outright blaming Oxitec and its GM mosquitoes.

While thorough questioning of scientific practices is welcome, especially for as important a topic as GM organisms, Parry said some of the circulating accusations are false and can affect lives.

"The WHO and Brazilian regulators have examined our technology and found no significant risk," he said. "However, if anyone has real evidence, or even a hypothesis to test out, they should come forward as that will be good for the debate."