Capital scientists in fight to conquer killer malaria

The team from Edinburgh University has worked out how some strains of the killer bug are able to survive current treatments in a discovery hailed as a breakthrough in treating the disease.

Several medicines are used to treat malaria, but the parasites, carried by mosquitoes, have quickly learned ways to resist their effects.

Now the Edinburgh team, along with scientists from Bangkok, have discovered exactly how they have been able to escape.

They say the research could have a "significant effect" on the disease, which claims at least a million lives across the globe each year.

The breakthrough came with the study of the malaria-causing parasite, Plasmodium vivax - responsible for more than 70 per cent of cases in South America.

By working out the structure of the protein which the parasite produces to help keep itself alive, scientists have provided a model from which a new kind of drug can be made.

Professor Malcolm Walkinshaw of the University of Edinburgh, said: "We can now use this protein structure to design a new generation of drugs which makes it possible to overcome resistant strains of malaria caused by the P.vivax parasite.

"People have studied the protein PvDHFR for a long time, but until now, no one has been able to determine its detailed structure. This is a real breakthrough."

The research, funded by Wellcome Trust, was carried out by scientists at Mahidol University and the BIOTEC Centre in Bangkok, in collaboration with the University of Edinburgh's Institute of Structural and Molecular Biology.

It is the second malaria-linked breakthrough for the team. In 2003, they showed how another parasite, the Plasmodium falciparum, builds resistance to drugs.

Until recently pyrimethamine was one of the most effective anti-malarial drugs.

It works by blocking the function of the protein of the parasite but, over the past 40 years, its widespread use has forced the insects to alter and become resistant to the drug.

Although not a problem in the UK, malaria is the most common infective killer throughout the tropics, affecting 300 million to 500 million people around the world every year.

It is common in Africa, Asia, South America and even a few European countries such as Turkey, Armenia, and Azerbaijan.

It is caused by an infection of the red blood cells with a tiny organism or parasite, called a protozoa. Symptoms include a fever, with sweating and shivers, exhaustion and in some cases, the brain is affected or patients suffer from kidney failure.

Immunity can be built up after living in a malaria-infected country, but is easily lost if travellers return to the UK. About 90 per cent of travellers who contract malaria do not become ill until after they return home.

Earlier this year, a team of scientists at Edinburgh University discovered malaria parasites had developed a "competitive" streak - enabling them to kill off weaker rivals for the "right" to make sufferers unwell.

This revealed that less virulent strains of the disease - which would be less harmful to humans - are stamped out within the body by stronger forms of the parasite.