Travel epidemiology: the Saudi perspective.

The Kingdom of Saudi Arabia occupies four-fifths of the Arabian Peninsula, with a land area of 2 million square kilometres. Saudi Arabia holds a unique position in the Islamic world, as the custodian of the two holiest places of Islam, in Mecca and Medina. Annually, some 2 million Muslims from over 140 countries embark on Hajj. This extraordinary en masse migration is a unique forum for the study of travel epidemiology since the Hajj carries various health risks, both communicable and non-communicable, often on a colossal scale. Non-communicable hazards of the Hajj include stampede and motor vehicle trauma, fire-related burn injuries and accidental hand injury during animal slaughter. Communicable hazards in the form of outbreaks of multiple infectious diseases have been reported repeatedly, during and following the Hajj. Meningococcal meningitis, gastroenteritis, hepatitis A, B and C, and various zoonotic diseases comprise some of the possible infectious hazards at the Hajj. Many of these infectious and non-infectious hazards can be avoided or averted by adopting appropriate prophylactic measures. Physicians and health personnel must be aware of these risks to appropriately educate, immunize and prepare these travellers facing the unique epidemiological challenges of Hajj in an effort to minimize untoward effects. Travel epidemiology related to the Hajj is a new and exciting area, which offers valuable insights to the travel specialist. The sheer scale of numbers affords a rare view of migration medicine in action. As data is continually gathered and both national and international policy making is tailored to vital insights gained through travel epidemiology, the Hajj will be continually safeguarded. Practitioners will gain from findings of travel related epidemiological changes in evolution at the Hajj: the impact of vaccinating policies, infection control policies and public health are afforded a real-world laboratory setting at each annual Hajj, allowing us to learn from this unique phenomenon of migration medicine.