Scientists have discovered a gene that enables the parasite responsible for malaria to become resistant to drugs.

The researchers, from Melbourne, Australia, have found that the parasite is able to change itself to fight off the effects of the chemicals used in anti-malaria drugs such as mefloquine, quinine and chloroquine.

The findings, published in the journal Nature, raise the possibility that more effective treatments could be developed to tackle the deadly disease.

Malaria kills approximately two million people world-wide each year - most of them in Africa.

At present, the malaria parasite is able to build up resistance to the commonly used drugs.

Scientists at the Walter and Eliza Hall Institute of Medical Research have shown that a mutation in a gene called pfmdr1 is behind the drug resistance.

Better drugs

Lead researcher Alan Cowman said: "A greater understanding of the mechanism used by the parasite to evade the lethal effect of these antimalarial drugs means we can consider developing ways of inhibiting this and increasing the efficacy of the current antimalarials."

The scientists warn that pfmdr1 is not the only gene involved in drug resistance but it is an important one.

They plan further work to better understand the role of the gene, and to look at other genes that may be involved in the process of building up drug resistance.

Most of the more than 300 million cases of malaria world-wide are caused by a parasite called Plasmodium flaciparum that attacks mature and young blood cells.

Although the mosquito-borne disease, which can also be transmitted through infected blood, can be cured, research has shown only about 10-20% of sufferers are given the correct drugs.

The World Health Organisation and other international agencies have launched a global initiative to fight malaria in Africa.