Image caption The mosquito is responsible for carrying the malaria parasite from human to human

Efforts to eradicate malaria in some countries may be counter-productive, an international team of researchers suggest.

In the Lancet, they suggest some countries, particularly in sub-Saharan Africa, may be better pursuing a policy of controlling the disease.

They also criticise the World Health Organization (WHO) for not providing adequate direction.

But a WHO spokesman said beating malaria must remain the ultimate goal.

'Noble' goal

The Lancet looks at the feasibility of eradicating malaria from the map, in the same way smallpox was conquered.

As the report points out, the Bill and Melinda Gates Foundation set the world such a target in 2007, an aim which was then endorsed by the WHO's Director-General Margaret Chan.

The Lancet concludes such a goal, while noble, "could lead to dangerous swings in funding and political commitment, in malaria and elsewhere".

And the WHO is accused of failing "to rise to their responsibilities to give the malaria community essential direction".

Malaria facts Largely preventable and curable

In 2008 caused a million deaths - mostly African children

About 2,000 return to the UK with malaria every year

Only 12% of these become seriously ill

Symptoms can take up to a year to appear Q&A: Malaria

The series of articles instead urges a pragmatic approach in which efforts and resources are concentrated on shrinking the global area where malaria still prevails.

It suggests some countries, particularly in sub-Saharan Africa, may be better pursuing a policy of controlling the disease rather than one of eradication.

The report's authors include Professor Richard Feacham of University of California's Global Health Group and researchers from the Clinton Health Access Initiative.

Saving lives

In an editorial accompanying the series, the Lancet's editor-in-chief Dr Richard Horton and executive editor Dr Pamela Das, argue control may save more lives.

"If existing control efforts were indeed scaled up, by 2015, 1.14 million children's lives could be saved in sub-Saharan Africa alone. This finding is important. The quest for elimination must not distract existing good malaria control work," they write.

They also conclude that "malaria will only be truly eradicable when an effective vaccine is fully available".

Premature efforts at elimination, before countries are ready, will be counterproductive Bill & Melinda Gates Foundation spokeswoman

Responding to the report in a statement, Robert Newman, director of the WHO's Global Malaria Programme, said the ultimate goal had to be eradication

"WHO has always supported - and will always continue to support - endemic countries in their efforts to control and eliminate malaria," he writes.

"It is entirely feasible to eliminate malaria from countries and regions where the intensity of transmission is low to moderate, and where health systems are strong.

"Eliminating malaria from countries where the intensity of transmission is high and stable, such as in tropical Africa, will require more potent tools and stronger health systems than are available today."

Shrinking map

Malaria is caused by five species of a parasite that can be carried from human to human by mosquitoes.

Over the last 150 years, the portion of the world where malaria is still endemic has shrunk, but the disease is still endemic in 99 countries.

However 32 of these countries, most of them on the edges of the endemic zone, are attempting to eradicate the disease, while the rest are trying to reduce infections and deaths though control measures.

But switching from a policy of controlling the disease to one of eradication brings with it problems and risks, according to the report.

The authors point out that malaria and mosquitoes do not respect national borders and that both parasite and insect may develop resistance to existing drugs.

They also warn switching funds from control to eradication may negatively impact upon measures which have been shown to reduce infection and mortality.

A spokeswoman for the Bill and Melinda Gates Foundation said: "Malaria eradication is a long-term goal.

"We believe that the WHO will play an important role in helping countries decide when they are ready to undertake elimination and what conditions and capabilities need to be in place for them to do so.

"High-level, sustained control will be essential before elimination can be attempted, and premature efforts at elimination, before countries are ready, will be counterproductive."