Experts: GM mosquitoes cannot transmit dengue – they do not bite

PETALING JAYA: Dengue and health experts have refuted claims that genetically-modified (GM) mosquitoes released are inducing a spike in dengue cases.

Institute of Medical Research (IMR) Entomology Unit head Dr Lee Han Lee said only male Aedes aegypti GM mosquitoes were released.

“Male mosquitoes do not bite,” he said. “These mosquitoes cannot transmit dengue and, therefore, will not cause an increase in dengue cases.”

The claims came about following an increase of more than 100,000 dengue cases last year.

On Thursday, the Health Ministry said a study on GM mosquitoes had been shelved as it was not cost effective.

A preliminary study was carried out from Dec 21, 2010, to Jan 5, 2011, to compare the behaviour of GM mosquitoes under natural conditions against their wild counterparts.

In the field trial undertaken by the IMR and Oxitec Ltd, about 6,000 male GM Aedes aegypti mosquitoes were released at an uninhabited forested area near Bentong, Pahang.

The GM mosquito would mate with the females in the wild and the eggs would hatch but the offsprings would die soon.

Deputy health director-general Datuk Dr Lokman Hakim Sulaiman concurred with Dr Lee.

“The reality is the breeding index is still very high, that’s why we are having pro­blems,” Dr Lokman said.

World Health Organisation Collaborating Centre for Arbovirus Reference and Research director Dr Sazaly Abu Bakar said hundreds of thousands of human hosts walking around with the dengue virus unprotected, including those without symptoms, was the likely reason for the increase.