It has fuelled the popularity of long-haul trips and adventure holidays to Asia and Africa and given gap year students the chance to visit all manner of far- flung locations. But as we've boldly gone to these remote places it has brought us into regions of the world where deadly diseases like malaria and tuberculosis are rife.

According to MASTA (Medical Advisory Services for Travellers Abroad) there has been a 150 per cent rise during the last 10 years in visits by Britons to countries where malaria exists. But despite this increase there are only about 2,000 reported cases a year of the disease being brought back to the UK.

This figure hasn't changed much in recent years, which is partly down to the fact that most travellers make sure they are immunised. MASTA runs more than 30 clinics across the country, including ones in Leeds and York, and has opened a new Sheffield clinic to cope with increased demand for vaccinations and advice from holidaymakers and travellers.

However, malaria and TB aren't the only tropical diseases that people are bringing back home. Several cases of dengue (or break-bone) fever and chikungunya, a viral disease caused by the same mosquitoes that spread Yellow fever, have been reported in the UK in recent years.

Michelle Sellors, a senior nurse adviser with MASTA, says travellers don't always take the necessary precautions when they go abroad. "A lot of people just think they need to get vaccinated against diseases like malaria when they go to Africa or Asia, but they forget about other airborne and waterborne diseases," she says.

"A few years ago there was a big outbreak of chikungunya in India which spread to the Seychelles and Mauritius and we did see quite a few people coming back to the UK with the disease."

Mrs Sellors also warns that despite the number of malaria cases in the UK remaining stable, there has been a worrying increase in more virulent strains of the disease. "We're getting more serious forms of malaria which is the dominant form of the disease in Africa and as more people travel there we're seeing more cases.

"The biggest risk is people visiting friends and family and bringing infections back, rather than holiday travellers. It's often people from Africa who live here and go back home and wrongly assume they're immune."

The latest figures show there have been 63 deaths among UK travellers from malaria since 2001 and while such figures don't constitute an epidemic, there are concerns these numbers will rise. Last month, the Health Protection Agency (HPA) warned that a deadly form of malaria, known as Plasmodium falciparum, was being imported into the UK by people being careless with their health while visiting friends and relatives in Africa.

According to the HPA, between 1987 and 2006 the number of reported cases in Britain of infection by this strain increased 32 per cent from 5,120 to 6,753. The organism, largely found in sub-Saharan Africa, is responsible for 80 per cent of malaria infections and 90 per cent of deaths worldwide.

Dr Ron Behrens, a consultant in tropical and travel medicine at the London Hospital for Tropical Diseases, says new strains of other infectious diseases are also emerging. "What is changing is we're seeing more resistant strains of some diseases. For example, we are seeing more strains of TB that are resistant to antibiotics."

And he admits there is a potential threat of a new virus arriving in the UK.

"If we were hit by a resistant strain of some disease then it could have huge implications for us, but there's not much we could do to prevent it."

But Dr Behrens also points out that infectious diseases account for just four per cent of deaths and injuries among UK travellers abroad, while heart attacks and strokes, along with traffic accidents, make up more than 90 per cent.

"It's not just about infectious diseases, people are much more likely to be killed or injured in a road traffic accident, than as a result of malaria or typhoid."