Malaysia has released 6,000 genetically modified mosquitoes into a forest in the first experiment of its kind in Asia aimed at curbing dengue fever.
The field test is meant to pave the way for the official use of genetically engineered Aedes aegypti male mosquitoes to mate with females and produce offspring with shorter lives, thus curtailing the population.
Only female Aedes aegypti mosquitoes spread dengue fever, which killed 134 people in Malaysia last year.
Malaysia has released 6,000 genetically modified Aedes aegypti male mosquitoes into a forest in a bid to curb rates of dengue fever
However, the plan has sparked criticism by some Malaysian environmentalists, who fear it might have unforeseen consequences, such as the inadvertent creation of uncontrollable mutated mosquitoes.
Critics also say such plans could leave a vacuum in the ecosystem that is then filled by another insect species, potentially introducing new diseases.
A similar trial in the Cayman Islands last year – the first time genetically modified mosquitoes have been set loose in the wild after years of laboratory experiments and hypothetical calculations – resulted in a dramatic drop in the mosquito population in a small area studied by researchers.
Government authorities have tried to allay the concerns by saying they are conducting small-scale research and will not rush into any widespread release of mosquitoes.
The Malaysian government-run Institute for Medical Research said it released about 6,000 non-biting sterile male lab mosquitoes in an uninhabited forest area in eastern Malaysia on December 21.
Another 6,000 wild male Aedes aegypti mosquitoes were also placed in the area for scientific comparison, it said in a statement.
The plan has sparked criticism by some environmentalists, who fear it might have unforeseen consequences, such as the inadvertent creation of uncontrollable mutated mosquitoes in the section of Malaysian forest
The institute provided few details of the experiment, but said it was ‘successfully’ concluded on January 5, and that all the mosquitoes were killed with insecticide.
It was not planning to release any more mosquitoes until it had analysed the results of the lab mosquitoes’ life span and extent of their dispersal in the wild.
It was the first such trial in Asia, an official in the Ministry of Natural Resources and Environment said on condition of anonymity because he was not authorised to make public statements.
In the Cayman Islands, genetically altered sterile male mosquitoes were also set loose by scientists in a 40-acre region between May and October last year.
By August, mosquito numbers in that area dropped by 80 per cent compared with a neighbouring area where no sterile mosquitoes were released.
Malaysian Prime Minister Najib Razak said last year the project was an ‘innovative’ way to fight dengue after a lack of success in campaigns urging Malaysians to keep neighbourhoods free of stagnant water where mosquitoes can breed.
The number of dengue-linked deaths in Malaysia increased by 52 per cent last year from 88 deaths in 2009. The total dengue infections rose 11 per cent from 2009 to more than 46,000 cases last year.
Dengue fever is common in Asia and Latin America. Symptoms include high fever, joint pains and nausea, but in severe cases, it can lead to internal bleeding, circulatory shutdown and death. There is no known cure or vaccine.