Over the last decade, the number of travelers crossing international borders has grown from 457 million in 1990 to 763 million in 2004. This increase in global travel has led to more frequent illness during travel and to instances of disease that is imported back to the country of origin; disease that may spread to susceptible contacts. The failure of health care professionals to accurately advise the traveler of health risks and the failure of the traveler to either seek or follow pre travel advice may lead to excess morbidity and mortality from diseases such as malaria.

There has been tremendous growth in the field of vaccinology, with the release of new vaccines to prevent infections, some which are related to travel. This will help to prevent travel related diseases and complications.