As international travels have become increasingly common for both business and tourism, physicians are confronted with innumerable travelers suffering from unknown syndromes and INFECTIOUS DISEASES, thus it is necessary for physicians to maintain familiarity with current guidelines and recommendations about travel medicine and prevention of related INFECTIOUS DISEASES.Fever, travelers' diarrhea, skin eruptions, respiratory and CNS involvement are DISEASES seen among travelers on return which make them visit the physicians.Consultation and a check up prior to traveling with the aim of immunization, recommendations about traveler's diarrhea, malaria and DISEASES transmitted by blood or sexual contacts are steps that could be taken by the physicians before travel. Knowledge about the epidemiology and etiology of traveler's DISEASES, destination and immunization status of travelers can prevent complications, morbidity and mortality attributed to INFECTIOUS DISEASES in travelers.

Background: Muslims participation in Mecca & Medina (Saudi Arabia) for Hajj which is the largest organized annual mass gathering in the world. In addition of Hajj, many pilgrims attend in Saudi Arabia for Umrah that is performed year-round. This great human immigration is an important challenge of health care and infection control systems. Current study reviews the most prevalent INFECTIOUS DISEASES among pilgrims during Hajj along with their mode of transmission and control.Materials and methods: A comprehensive search was done on PubMed, Science Direct & Google Scholar databases by using Hajj, Pilgrims, INFECTIOUS DISEASES & Mecca as keywords. Our search was restricted to English & Persian papers from 1994 to 2014.Results: Overall, 97 papers were found. After omitting old and repeated reports, 64 articles were reviewed finally.Conclusion: Due to scale of Hajj and prevalence of various INFECTIOUS DISEASES such as meningococcal infections, diarrheal DISEASES and Influenza preventive measures and vaccination are recommended both before and during pilgrimage. Pilgrims and health care workers must be educated about health hazards and protective behaviors.