The annual Hajj pilgrimage-minimizing the risk of ill health in pilgrims from Europe and opportunity for driving the best prevention and health promotion guidelines.

Mass gatherings at religious events can pose major public health challenges, particularly the transmission of infectious diseases. Every year the Kingdom of Saudi Arabia (KSA) hosts the Hajj pilgrimage, the largest gathering held on an annual basis where over 2 million people come to KSA from over 180 countries. Living together in crowded conditions exposes the pilgrims and the local population to a range infectious diseases. Respiratory and gastrointestinal tract bacterial and viral infections can spread rapidly and affect attendees of mass gatherings. Lethal infectious disease outbreaks were common during Hajj in the 19th and 20th centuries although they have now been controlled to a great extent by the huge investments made by the KSA into public health prevention and surveillance programs. The KSA provides regular updated Hajj travel advice and health regulations through international public health agencies such as the WHO, Public Health England, the Centers for Disease Control and Prevention, and Hajj travel agencies. During the Hajj, an additional 25 000 health workers are deployed; there are eight hospitals in Makkah and Mina complete with state-of-the-art surgical wards and intensive care units made specifically available for pilgrims. All medical facilities offer high quality of care, and services are offered free to Hajj pilgrims to ensure the risks of ill health to all pilgrims and KSA residents are minimal. A summary of the key health issues that arise in pilgrims from Europe during Hajj and of the KSA Hajj guidelines, together with other factors that may play a role in reducing the risks to pilgrims and to wider global health security, is provided herein.