It's possible to die within 24 hours of developing the first symptom

Dr Richard Dawood, travel health expert

There are more than 2,000 cases a year diagnosed in this country - many of which do not emerge until some weeks after the traveller has returned to the UK.

Malaria is fatal in a small number of cases in this country, causing serious illness and even lasting disability in many others.

It is caused by a microscopic parasite which can be passed into humans when they are bitten by various types of mosquitoes.

Malarone is a combination of two existing anti-malarial drugs, and can target the parasite which causes the illness at two stages of infection while it is both in the liver, and in the bloodstream.

Horror story

Angela Green, who survived a bout of malaria following a single mosquito bite during a trip to Africa, is still feeling the after-effects.

"My body's circulation system shut down, my liver and kidneys weren't working, and I had no feeling in my legs and feet.

Angela Green narrowly survived malaria

"That was my lowest point - and afterwards they told me that I nearly died then.

"Even after I came out of hospital, I couldn't walk, was extremely tired - I lost my toenails."

"If I meet anyone who says they are going to these countries without taking anti-malaria drugs, I tell them they are absolutely mad."

GlaxoSmithKline, which manafactures Malarone, says the drug is 97% effective against the parasite.

However, the drug is considerably more expensive than Lariam, the standard anti-malarial currently available at travel clinics.

Malaria remains a major killer disease in a large number of countries, despite efforts at eradication involving swamp clearance and insecticides to reduce the numbers of the mosquitoes.

Dr Richard Dawood, a specialist in travel medicine and editor of Traveller's Health magazine, said: "Most people might not realise how rapidly malaria can progress.

"It's possible to die within 24 hours of developing the first symptoms."