Travel epidemiology: WHO perspective.

International travel is undertaken by increasing, numbers of people for professional, social, recreational and humanitarian purposes, and this trend looks set to continue. Travellers are exposed to a variety of health risks of the unfamiliar environment of the area visited. Most such risks can be minimized by suitable precautions taken before, during and after travel. Furthermore travellers can introduce any infectious agents they may harbour to the visited area. Because of rapid air travel, no country is safe from infectious diseases and an outbreak in one country can easily and rapidly be transmitted across long distances to affect other countries through travel and trade. The main WHO strategies for minimizing the negative effects of expanding travel on global health security include developing the necessary strategies, rules and regulations, strengthening global communicable diseases surveillance and response, dissemination of related information throughout the world and strengthening national capacity for communicable diseases surveillance and response.