By Ian Muir-Cochrane
BBC Radio and Current Affairs
The way the World Health Organization gathers data on how malaria deaths does not represent the true scale of the problem, say experts.
Children are particularly at risk
The disease kills more than a million people a year - most of them young children in sub-Saharan Africa.
The WHO has set itself an ambitious target of halving the number of cases around the globe by the year 2010.
However, figures published by the organisation this year have been queried by malaria scientists in Kenya.
A leading researcher in the field, Bob Snow, Professor of Tropical Public Health at the University of Oxford has spent 16 years in Kenya, working on the front line in the fight against Malaria.
THE INSIDE STORY OF THE WHO (Part II):
Tuesday, 6 September 2005
BBC RADIO 4, 2000 BST
Repeated Sunday 11 September 2005, 1700 BST
Earlier this year he published new research showing the numbers of infections globally of the most deadly form of the disease were almost double that which had been previously estimated by the WHO.
Professor Snow said: "What we wanted to do was to produce a transparent and reproducible way of estimating disease burden worldwide.
"In Africa there are a million people a year that die of malaria, and this was considerably higher than WHO had estimated, and the primary reason for that is that WHO rely on national statistics, so you will get only those that go to government clinics."
Earlier this year the WHO published the World Malaria Report which appears to show that the number of people who died in 2002 from Malaria in Kenya was only 135.
Professor Snow says a more accurate assessment would be 36,000.
When the BBC raised the discrepancy with the WHO representative in Nairobi, Dr Peter Eriki, there seemed to be some confusion as to how the figure had been arrived at.
He said: "I don't think that it is accurate information, we do not have figures of our own we work with the Ministry, so we rely on the government of Kenya.
"We are working with them to really update this information and get the latest."
Later the WHO told the BBC that the figure of 135 deaths referred to mortality recorded by the government at just one hospital and that this was made clear by an unreferenced footnote.
But the method the WHO uses for gathering information on cases of disease is, according to, Professor Nick White who studies malaria in South East Asia , an illustration of a worrying trend.
"Because the WHO is a UN body, it feels an obligation to use the country's own information.
"But it has become abundantly clear that much of the data on how much disease they have is not correct.
"They have had no method of knowing how much malaria they have had.
"I think it would have been much better if it had been conceded that these methods weren't working."
With estimates for the number of malaria cases in the world ranging from 300,000 to half a billion, researchers like Professor Snow hope that a more accurate picture of the effect of the disease will encourage the international community to put more funds into tackling it.
"If you don't have the right numbers on the size of the problem, it's very hard to estimate how much money you need, this is where getting the numbers right is so important."
" In failing health? The inside story of the WHO" (Part I) will air on 30 August 2000 BST, Radio 4, with a repeat on 4 September 1700 BST.