With thousands of Irish people racing to book their holidays this month, a new study warns that those opting for more tropical destinations should be aware of the dangers of malaria and typhoid fever.

Every year, some 50 million Western travellers choose to go to tropical destinations, such as Africa, Asia and Central America. Norwegian scientists looked at over 82,000 people who had returned from various holidays and had sought medical care for illnesses.

They found that over 3,600 of these had caught malaria, typhoid fever or some other dangerous tropical disease.

"While diagnosis and treatment of malaria and typhoid fever and many other tropical diseases have improved greatly over the years, people still can die from them if they are not treated quickly after their symptoms begin," said one of the scientists, Dr Mogens Jensenius, of the University of Oslo.

He emphasised that as a result of this, doctors and nurses in Western countries ‘need to be vigilant in considering these potentially life-threatening tropical infections in recently returned travellers with fevers'.

Identifying them quickly is essential, he said.

Overall, malaria was the most commonly-seen tropical infection in returned travellers. The disease, which is spread by mosquitoes, accounted for three in four cases.

Almost one in five infections were caused by fevers, including typhoid fever, which is contracted from contaminated water and food in areas with poor sanitation.

Just over 2% of sick travellers were diagnosed with leptospirosis, a rare infection usually caused by contaminated water.

The scientists pointed out that most cases of malaria were seen in travellers to West Africa, while typhoid fever was more commonly seen in those who had visited India.

However, they also noted that there were no cases of ebola, which they say, is the disease most feared by travellers to tropical locations. There were also no cases of yellow fever or Lassa fever.

"We were quite surprised that these much-feared viral infectious diseases were completely absent. People talk about them all the time, but our paper suggests that these are still very, very rare among travelers," Dr Jensenius explained.

He added that according to the World Tourism Organisation, the number of Western travellers to tropical destinations is expected to increase in the coming years.

Details of these findings are published in the American Journal of Tropical Medicine and Hygiene.