Malaria claims 30 million lives in three decades

Imagine a disease that in the course of a single year wiped out the equivalent of the entire population of Abu Dhabi. That is the human cost of malaria; a death toll that is the equivalent of six Airbus 380 jumbo jets crashing every day. With no survivors.

Statisticians have always struggled to estimate the ravages of malaria worldwide. Until recently, the best estimate was that 655,000 people died from the disease in 2010, the last year for which figures are available.

That total, from the World Health Organization, was challenged last week by new research published in the British medical journal, The Lancet, and funded by the Bill and Melinda Gates Foundation.

Using a new computer modelling system and a much bigger database, the research team has doubled the number of malaria deaths in 2010 to 1.24 million.

Even a conservative estimate suggests that by recalculating the figures from 1980, the past three decades have seen more than 30 million people die from malaria, or more than the populations of the UAE and Australia combined.

The Gates Foundation research makes a challenging and harrowing read. Children are dying in much greater numbers than had previously been thought. Worldwide, more than half a million children under the age of five are killed by malaria every year. More than three out of four of those deaths happen in Africa. The report also challenges the long-held belief that surviving malaria in childhood provides immunity for life. In fact, it says, almost a third of all deaths occur between the ages of 15 and 80.

If correct - and the WHO disputes some of the calculations - the new figures are a serious blow to the United Nations' objective of halting and reversing the number of malaria cases by 2015, as called for in its Millennium development goals. And the prospect of eradicating the disease entirely, as with smallpox and, most recently, the cattle disease rinderpest, look even more distant.

Yet the news is not all bad. Malaria death rates have been declining year on year since their peak in 2005. At the turn of the century, it was killing nearly 25,000 children under the age of five in India. Now annual malaria deaths in the subcontinent are less than 5,000.

In Afghanistan, the numbers have fallen by three-quarters; in Morocco the disease has been entirely eradicated among younger children. More than 20 countries have set themselves a realistic goal of eradicating malaria in the next two decades, including near-neighbours Saudi Arabia, Iraq and Iran.

And even as it wrestles with the higher death toll, the Gates Foundation remains optimistic that malaria can be consigned to the history books. Since calling for the eradication of the disease five years ago, the founder of Microsoft and his wife have poured hundreds of millions of dollars into research and intervention.

Some of the tactics seem simple: distributing bed nets treated with insecticide to keep out mosquitoes. More exciting is the prospect of vaccine, and the news, in December, that early tests of a drug on animals in Britain had shown encouraging results.

Other drugs combat the symptoms of the disease once it has taken hold. Many have proved highly effective, but four years ago, researchers in Cambodia noticed patients were taking much longer to recover, even when given one of the most potent drugs. The parasite that causes malaria, it turned out, had developed its own resistance to the drug. Malaria, even when it is on the run, is a disease that can still bite back.