Malaria in travellers to Gambia.

Malaria incidence is reportedly declining steadily in many parts of the world, including in at least several African countries. The incidence of imported malaria is also declining in a number of European countries. However, incidence rates in travellers, both European tourists and the so called VFR (visiting friends and relatives) are difficult to estimate, due to problems with the numerator (many cases are not reported) and more importantly with the denominator, for which the information is generally lacking. An exception in the European Union is the United Kingdom (UK), where the International Passenger Survey provides a reliable denominator on the number of travellers to the different countries, duration of stay and reason for travel.