Scientists have created a genetically modified mosquito in the first step of a bold plan to alter an entire species to wipe out malaria.

They inserted a synthetic gene that blocks the development of the malaria parasite in the mosquitoes, making it difficult for them to transmit it to humans.

The gene, called SM1, is integrated into the mosquito and passed from one generation to the next.

"This introduces a completely new approach against malaria and the more approaches we have to fight the disease the better," Professor Marcelo Jacobs-Lorena said in an interview on Wednesday.

The geneticist at Case Western University in Cleveland, Ohio led the team of scientists who developed the gene which could potentially transform an entire species -- a feat normally accomplished through natural selection.

"The plan is to wipe out malaria by transferring this gene to the entire population of malaria-carrying mosquitoes," Jacobs-Lorena said. But he emphasised that it is only a step in that direction.

In animal studies, the GM mosquito was 80 percent less effective in a spreading the parasite. More tests are also needed to prove the technique is safe and that the gene cannot be passed on to humans.

"We have to be very careful before we move to release anything into nature. We have to make sure there are not any harmful aspects," he said.

Milestone in malaria research

If tests prove it is safe and effective, Jacobs-Lorena believes the approach could be used to fight malaria in five to 10 years. When it is perfected, it will probably be incorporated with other more conventional methods to wipe out the disease that affects as many as 500 million people each year.

"I am a firm believer that the final solution for eradicating malaria will only be possible if one uses a multi-prong approach, combining this transgenic approach with drugs, insecticides and hopefully with vaccines as well," he said.

In research reported in the science journal Nature, the scientists described how they created GM Anopheles stephensi mosquitoes, which transmit the malaria parasite on the Indian subcontinent, and studied the impact on mice.

The next step is to test the technique in humans using Anopheles gambiae, the type of mosquito which is responsible for transmitting the disease in Africa, where over 90 percent of malaria deaths occur.

"This is proof of principle and as such is a milestone in malaria research," said Gareth Lycett and Fotis Kafatos, of the European Molecular Biology Laboratory in Germany.

In a commentary in the magazine they added that the achievement opens up a new era in malaria-related research.

Malaria is caused by a tiny parasite that is transmitted by the bite of the female mosquito. It causes fever, muscle stiffness, sweating and shaking.

The synthetic gene blocks the parasite from passing from the gut to the saliva of the mosquito, which prevents the insect from infecting humans.

(People's Daily May 23, 2002)