Health experts claim that British travellers remain unaware of the dangers of malaria, despite it being endemic in more than 100 countries. More than five million Britons travelled to high-risk malaria areas last year, but a quarter of them were ignorant of the health hazards, the organisers of Malaria Awareness Week said.

And 60% failed to seek travel health advice before venturing abroad, despite a recent estimate of 500 million worldwide cases each year of the most lethal form of the disease - falciparum.

Each year, around 2,000 UK travellers return from overseas with malaria. Deaths in the UK increased from eight in 2002 to 16 in 2003. Dr George Kassianos, a member of the UK Malaria Guidelines Committee, said: "In its most severe form, malaria is a dangerous and life-threatening disease.

"What we are seeing far too often is people not taking anti-malarial medicine, taking the wrong medication for the country they are visiting, or not completing the course for the prescribed time after leaving the malarious area."

He said: "Everyone travelling to a malarious country must be aware that all it could take is just one bite from an infected mosquito to contract the disease.

"There is no room for complacency, so travellers are urged to seek medical advice before they travel, and take sensible and effective precautions."

TV presenter John Craven urged people to take note of the Malaria Awareness campaign.

He said: "My father contracted malaria and suffered from it recurrently throughout his life. "I encourage all UK travellers to seek health advice before setting out on their travels."