Malaria study shows survival is in the blood

Some people in Papua New Guinea have inherited a protein that makes infections less severe

SYDNEY - Scientists have found a protein mutation in the blood cells of some Pacific islanders that helps them to survive malaria, a discovery that should help efforts to develop a vaccine for the deadly disease, it was reported yesterday.

Researchers Alan Cowman and Alex Maier of the Walter and Eliza Hall Institute in Melbourne, Australia, led the international study that found 45 per cent of Melanesians in infected areas had inherited the ability to block a key pathway used by the malaria parasite.

According to the study, to be published in next month's edition of the journal, Nature Medicine, the protein mutation spread through the Melanesian population in and around Papua New Guinea via natural selection - those who have it survive childhood bouts of malaria and pass the trait on to their children.

'Malaria kills kids usually under five years of age and if you don't survive until adulthood, you don't pass your genes on,' Dr Cowman told the Australian Associated Press.

'So, if you have a mutation that allows you to survive until adulthood, you pass your genes on, and that mutation continues and gets selected for over time,' he said. 'That's what's happened here.'

Dr Cowman and Dr Maier's study emphasised that the protein mutation did not make people immune to malaria, as the mosquito-borne parasite can enter red blood cells through other paths.

However, the mutation does make the infections less severe.

It involves a protein on the surface of the blood cells and its discovery has shown scientists that a successful vaccine would have to stop the parasite invading red blood cells at a number of different points, Dr Cowman said.

'Now we've identified this next molecule, and we've got others as well... We should be able to develop one drug that blocks all of the pathways,' he said.

The study was the result of 2 1/2 years of research led by the Melbourne team in partnership with scientists based in Papua New Guinea and the state of Ohio in the United States. --AFP