mass gathering medicine (hajj pilgrimage in saudi arabia): the clinical pattern of pneumonia among pilgrims during hajj. | the planned annual hajj to the holy shrines in makkah, saudi arabia, is recognized as one of the largest recurring religious mass gatherings globally, and the outbreak of infectious diseases is of major concern. we aim to study the incidence, etiology, risk factors, length of hospital stay, and mortality rate of pneumonia amongst pilgrims admitted to al-ansar general hospital, madinah, saudi arabia during the hajj period of december 2004-november 2013. a retrospective analysis of all patients di ... | 2016 | 27262693 |