Health

Malaria: Huge progress on global killer

Mosquito Image copyright CDC

The World Health Organization is reporting a huge fall in the number of cases of malaria.

It has long been one of the world's biggest killers so what has changed and is eradication now a possibility?

What is malaria?

Malaria is caused by a parasite called plasmodium which initially hides in the liver before going into the bloodstream and infecting the red blood cells which carry oxygen around the body.

The parasites breed and burst out of red blood cells every 48 to 72 hours and each eruption of parasites is accompanied by a bout of fever, chills and sweating.

The parasites are spread from person to person by mosquitoes when they drink blood.

A single bite from the high-pitched whining insects is all it can take to become infected.

How much have cases fallen?

In 2000, there were 262 million cases of malaria infection and 839,000 people died.

The latest report by the World Health Organization and Unicef said malaria death rates had fallen by 60% and the cases had fallen by 37% .

They estimate that 6.2 million lives have been saved, with the vast majority being children.

In Africa, it is estimated that 700 million cases of malaria have been prevented since 2000 and it is no longer the biggest cause of death on the continent.

How has it been achieved?

Efforts to control malaria focus on preventing people being bitten by mosquitoes and treating them once they have malaria.

In Africa:

  • 68% of the fall in cases was down to the distribution of a billion insecticide-treated bed nets
  • 22% was attributed to the drug treatment artemisinin
  • 10% to spraying homes with insecticide

Two thirds of at-risk children around the world are now sleeping under insecticide treated nets.

Is resistance a problem?

Two forms of resistance are threatening to undo the progress made.

In South East Asia, the malaria parasite is able to shrug off the effects of the drug artemisinin. The drug is supposed to be used in combination with other drugs to prevent resistance however there are concerns about how the drug is being used.

Artemisinin resistance has been spreading and is now on the verge of entering India and experts have described that as both "alarming" and an "enormous threat".

Meanwhile, some mosquitoes are becoming resistant to the drugs used to coat the bed nets.

Can malaria be eradicated?

There has already been great progress in tackling malaria with the disease being driven out of Europe, North America, the Caribbean and parts of Asia and South-Central America.

The WHO says 13 countries that had malaria in 2000 no longer have any cases of the disease and a further six reported fewer than 10 cases.

It shows the disease can be eliminated from countries and potentially could be eradicated completely.

However, sub-Saharan Africa remains the epicentre of the disease and there are still hundreds of thousands of cases on the continent each year.

It will require further significant progress here before talk of eradication is taken seriously.