Résumé
Background & objectives The congregation of a large number of people during Hajj seasons from different parts of the world in overcrowded conditions within a confined area for a long period of time presents many public health challenges and health risks. One of the main health problems of the crowding is ease transmission of pneumonia by air droplets. This study was aimed to determine the most common causes of bacterial pneumonia during the 2005 Hajj season and to relate the findings with clinical conditions. Methods A total of 141 patients with suspected pneumonia from the three main tertiary care hospitals in Makkah, Saudi Arabia, were investigated during Hajj season, 2005. Sputum and serum samples were collected and investigated for the possible presence of typical or atypical causative agents. Results Of the 141 clinically suspected pneumonia cases, 76 (53.9%) were confirmed positive by microbiological tests. More than 94 per cent of the confirmed cases were in the age group >50 yr, and 56.6 per cent of the cases were men. The most frequent isolates were Candida albicans (28.7%) and Pseudomonas aeruginosa (21.8%), followed by Legionella pneumophila (14.9%) and Klabsiella pneumoniae (9.2%). More than one causative pathogens were isolated in 15 patients (16.3%), and 55 per cent of patients were diabetic. Interpretation & conclusions Clinicians should be aware that typical pneumonia treatment regimens may not work well during the Hajj season due to the wide variety of isolated organisms. This necessitates taking a sputum sample before starting treatment for identification and sensitivity testing. Special precautions need to be taken for >50 yr old patients.