Aedes Killer or Mutant Menace?

GM 'warrior' mosquitoes to fight dengue scourge in Malaysia. Environmentalists call it a bad idea.
The New Paper 29 Apr 08;

IN a bid to fight the spread of dengue fever, millions of genetically-modified (GM) 'warrior' mosquitoes will soon be released in the fishing village of Pulau Ketam off Selangor to kill off the deadly Aedes mosquito.

However, the experiment has come under fire by environmentalists, who fear that these modified insects will endanger the ecosystem and cause further damage.

The New Straits Times reported that field trials involving the GM mosquitoes will be undertaken by the Health Ministry's Institute of Medical Research (IMR) in collaboration with British-based Oxitec Ltd, an insect bio-tech company partly-owned by the University of Oxford.

According to researchers, the male Aedes aegypti mosquito was genetically modified to carry a killer gene. When these GM mosquitoes mate with female Aedes mosquitoes, the lethal gene causes the larvae to die.

Only the female Aedes mosquito can spread the dengue virus.

Malaysia has expressed concern about the insect-borne scourge after 25 people were killed in the first three months of the year.

The field testing of the GM mosquitoes is expected to be conducted on Pulau Ketam, about 30-minutes by boat from Port Klang, at the end of the year or early next year. The testing is expected to last about a year.

A team in Malaysia is currently undertaking a baseline survey of the island, which is reported to be teeming with Aedes aegypti mosquitoes.

Oxitec is also recruiting people for the Pulau Ketam field test on its website. The positions available include one for a senior entomologist.

In February, the British firm had announced its plans to to release the GM mosquitoes in Malaysia on a large scale in three years, following its successful trials.

Oxitec's head of public health Seshadri S Vasan told Calcutta's The Telegraph in a recent interview that the first confined field study under the supervision of the IMR 'yielded encouraging results'

Sources revealed that the lab trials done in Malaysia were the first in the world and a breakthrough in the fight against dengue, which has grown to alarming proportions across the globe in recent years, NST reported.

The Aedes mosquito is seen as the main cause of the spread in dengue fever and chikungunya fever. Conventional methods of controlling the spread of the diseases, such as fogging, have been ineffective.

Mr Vasan told The Telegraph: 'Conventional Aedes control methods have not been able to prevent outbreaks as is evident from the experience of a highly committed and organised city like Singapore.

'This is because of the low entomological threshold for transmission - as few as two or three adult female Aedes aegypti mosquitoes emerging every day in a locality of 100 people could be a sufficient threshold for a dengue threat.'

Entomology is the scientific study of insects.

But despite the potential eradication of the dengue scourge, environmental non-governmental organisations fear that the trial could make matters worse.

Mr Gurmit Singh, the chairman of the Centre for Environment, Technology and Development, said: 'Like all GM organisms, once they have been released in the wild, how do you prevent them from interacting with other insects and producing mutants which may be worse than the Aedes mosquito?'

Health Ministry and IMR officials did not want to comment on the tests.

In Singapore, the number of dengue victims is still on the rise despite the stepped-up efforts of the National Environment Agency to fight mosquito breeding.

In the first 15 weeks of this year, 1,401 people were afflicted with dengue, compared to 944 in the same period last year.