Oxford researchers call for new malaria distribution maps

There is a pressing need to define accurate maps of global malaria risk if international initiatives to reduce the disease are to be fairly targeted. This is the conclusion made by Dr Simon Hay and colleagues from the Oxford UniversityZoology Department after an analysis of past, present and future global malaria distribution and the populations that are at risk.

In a study published in this month's The Lancet: Infectious Diseases, the team used geographical information systems and historical maps to investigate the changes in global and regional malaria risk distribution between 1900 and 2002. They found that during the last century development and malaria control have reduced the world-wide area of malaria risk by half, from 53 to 27 per cent of the earth's land surface. During the same time period the percentage of the global population at risk from malaria decreased from 77 to 48 per cent.

However, a regional analysis of population at risk of malaria infection revealed that only Europe showed a consistent decrease during the last century. The team's most striking findings were that during the same period the number of people at risk from malaria has grown by 0.59 billion in Africa and by 1.3 billion in South East Asia.

To date many malaria initiatives have focused their resources on Africa, including the Roll Back Malaria movement, which aims to halve the global malaria burden by 2010. Though Dr Hay and colleagues stress that the burden of malaria mortality is concentrated in those African countries which are least able to raise the money to tackle the disease, and therefore this emphasis is largely justified, their research has highlighted that there are other areas, notably South East Asia, that are also in need of international attention. To ensure that money and resources are targeted at the areas that need them, Dr Hay and his team believe that improving techniques for mapping of the global extent of malaria risk and disease is an urgent priority.

Dr Hay said: 'Assessing the impact and equity of malaria related development initiatives requires improved information on the distribution and magnitude of the malaria problem. If we can't reliably mark our goal posts; how can we tell if we have scored?'