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 diagnosed and admitted as pneumonia was done. Patients were assessed according to the CURB-65 scoring system and admitted to the ward or intensive care unit accordingly. Throat and nasopharyngeal swabs, sputum, and blood culture were collected prior to antibiotic treatment. 1059 patients were included in the study (23% of total hospital admissions and 20% of ICU admissions). The mean age of participants was 56.8 years, the Male:Female ratio was 3:1, and the lengths of stay in the ward and intensive care units were 5 and 14.5 days, respectively. The main organisms cultured from sputum were Klebsiella Pneumoniae, Streptococcus Pneumoniae, Haemophilus Influenzae, Staphylococcus Aureus, Pseudomonas aeruginosa, and community-acquired MRSA. The mortality rate in the ward was 2.4%, while the rate in the ICU was 21.45%. The organisms which caused pneumonia were found to be different during Hajj. The usual standard guideline for the treatment of pneumonia was ineffective for the causative organisms. Therefore, specific adjustments in the guidelines are needed. All efforts should be made to determine the infectious agent. Healthcare workers and pilgrims should adhere to preventive measures. (C) 2016 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Limited. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
