emerGInG InfecTIouS DISeaSeS anD TraVel meDIcIne. SpecIal GroupS of TraVelerS

S optimistic scientists of the 20th century imagined that it might be possible with interventions such as antimicrobials and vaccines to close the book on infectious diseases. Unfortunately, infectious diseases remain among the leading causes of death worldwide, despite remarkable advances in medical research and abstract. The term „emerging infectious diseases” (EID) is a broad one that covers newly recognized human diseases caused by pathogens that have recently jumped species, older pathogens that have emerged in new populations due to humans behaviors or modifications to natural habitats, and older pathogens that are exhibiting resurgence in area once brought under control. EID are those with increasing incidence at local, regional or international scales and are spreading from epicenters to new geographic area. Travelers are important factor in the global dissemination of EID due to the increased frequency and speed of both local and international travel. Numerous epidemiologic studies suggest an upward trend in the incidence of reported cases of zoonoses over the past decade. Many of the diseases caused by emerging infections are vectored diseases (West Nile, chikungunya, malaria, Lyme borreliosis). Pathogens that are transmitted through aerosolized droplets have huge potential for rapid global spread. Exemples of pathogens in this group are avian (H5N1) influenza, and recently the new H1N1 swine influenza virus, extremely drug-resistant tuberculosis and severe acute respiratory syndrome (SARS) coronavirus. Changes in animal production system and in the food production chain are thought to be among the main factors causing emergence of food-borne zoonoses. The world’s holy places can be a magnet for the ailing, the disabled and the infirm. Each year millions of men and women go on pilgrimages. Problems of sanitation and disease transmission in large groups put pilgrims at high risk from gastrointestinal and respiratory illnesses, with variable risks according to the geographical location and specific religious customs. Travelers should know that the basic principles of food and water hygiene apply even in this context.