Etiology of Severe Community Acquired Pneumonia among Adult Patient in Repeated H5N1 epizootic area, Uttradit Province, Thailand, 2008(สาเหตุการเกิดโรคปอดอักเสบชนิดรุนแรงในชุมชน ในผู้ใหญ่บริเวณพื้นที่ที่มีการระบาดซ้ำซากของโรคไข้หวัดนกในสัตว์ปีก จ.อตรดิตก์

Thailand has been affected with influenza A (H5N1) virus since 2003. A nationwide surveillance was developed in order to detect H5N1 infection among pneumonia and influenza cases contacted with sick/dead poultries. In that connection, severe community acquired pneumonia (SCAP) was included in the existing surveillance system yet without its etiology. As such, this study was aimed at detecting cause of infection in the repeated H5N1 epizootic areas in Thailand. A hospital based cross-sectional study was conducted among adult SCAP cases in a provincial hospital located in the lower northern part of Thailand, as defined by Infectious Diseases Society of America/American Thoracic Society Consensus Guidelines 2007. A total of 157 cases were reported from Uttradit Provincial Hospital, during January - December 2008. No reported history of poultry contact before onset of illness in all of them. Their mean age was 66.7 (19 - 94) years; 54.8 percent were male, and 41.1 percent were fatal. Bacteria (47%) were common pathogen of the cases followed by viral (12%), co-infection viral with bacteria (6%) and unidentified etiology (35%). Of 111 bacterial infections diagnosed in 83 cases; 32.4 percent were atypical bacteria 25.2 percent were gram negative bacilli; Staphylococcus aureus (7.2%), Mycobacterium ssp. (5.4%), Streptococcus pneumonia (4.5%) and BurKholderia pseudomallei (2.70%). A common viral pathogen was Coronavirus, 6 (27.3%), whereas only 4 (18.2%) cases were identified with influenza A. In conclusion, the etiology confirmed common causative agents as at ypical bacteria following gram negative bacilli in bacterial group, also human Coronavirus was the most commonly detected in the cases. Eventhough cases lived in the repeated H5N1 epizootic areas, no confirmed human H5N1 case was detected. This finding showed the inefficient H5N1 transmission from the environment to human without poultry contact. Key words: severe community pneumonia acquired-SCAP, ICU, H5N1, virus, etiology, Thailand