Ruiz M, Ewig S, Marcos M A, Martinez J A, Arancibia F, Mensa J, Torres A
Department of Medicine, University of Barcelona, Barcelona, Spain.
Am J Respir Crit Care Med. 1999 Aug;160(2):397-405. doi: 10.1164/ajrccm.160.2.9808045.
The aim of this study was to determine the etiology of community-acquired pneumonia (CAP) and the impact of age, comorbidity, and severity on microbial etiologies of such pneumonia. Overall, 395 consecutive patients with CAP were studied prospectively during a 15-mo period. Regular microbial investigation included examination of sputum, blood culture, and serology. Sampling of pleural fluid, transthoracic puncture, tracheobronchial aspiration, and protected specimen brush (PSB) sampling were performed in selected patients. The microbial etiology was determined in 182 of 395 (46%) cases, and 227 pathogens were detected. The five most frequent pathogens were Streptococcus pneumoniae (65 patients [29%]), Haemophilus influenzae (25 patients [11%]), Influenza virus A and B (23 patients [10%]), Legionella sp. (17 patients [8%]), and Chlamydia pneumoniae (15 patients [7%]). Gram-negative enteric bacilli (GNEB) accounted for 13 cases (6%) and Pseudomonas aeruginosa for 12 cases of pneumonia (5%). Patients aged < 60 yr were at risk for an "atypical" bacterial etiology (odds ratio [OR]: 2.3; 95% confidence interval [CI]: 1.2 to 4.5), especially Mycoplasma pneumoniae (OR: 5.3; 95% CI: 1.7 to 16.8). Comorbid pulmonary, hepatic, and central nervous illnesses, as well as current cigarette smoking and alcohol abuse, were all associated with distinct etiologic patterns. Pneumonia requiring admission to the intensive care unit was independently associated with the pathogens S. pneumoniae (OR: 2.5; 95% CI: 1.3 to 4.7), gram-negative enteric bacilli, and P. aeruginosa (OR: 2.5; 95% CI: 0.99 to 6.5). Clinical and radiographic features of "typical" pneumonia were neither sensitive nor specific for the differentiation of pneumococcal and nonpneumococcal etiologies. These results support a management approach based on the associations between etiology and age, comorbidity, and severity, instead of the traditional syndromic approach to CAP.
本研究的目的是确定社区获得性肺炎（CAP）的病因，以及年龄、合并症和病情严重程度对这类肺炎微生物病因的影响。在15个月的时间里，对395例连续性CAP患者进行了前瞻性研究。常规微生物学检查包括痰液检查、血培养和血清学检查。对部分患者进行了胸腔积液采样、经胸穿刺、气管支气管抽吸和防污染样本毛刷（PSB）采样。395例患者中有182例（46%）确定了微生物病因，共检测到227种病原体。最常见的5种病原体分别是肺炎链球菌（65例患者[29%]）、流感嗜血杆菌（25例患者[11%]）、甲型和乙型流感病毒（23例患者[10%]）、军团菌属（17例患者[8%]）和肺炎衣原体（15例患者[7%]）。革兰氏阴性肠道杆菌（GNEB）占13例（6%），铜绿假单胞菌导致12例肺炎（5%）。年龄<60岁的患者有感染“非典型”细菌病因的风险（优势比[OR]：2.3；95%置信区间[CI]：1.2至4.5），尤其是肺炎支原体（OR：5.3；95%CI：1.7至16.8）。合并肺部、肝脏和中枢神经系统疾病，以及当前吸烟和酗酒，均与不同的病因模式相关。需要入住重症监护病房的肺炎独立地与肺炎链球菌病原体（OR：2.5；95%CI：1.3至4.7）、革兰氏阴性肠道杆菌和铜绿假单胞菌（OR：2.5；95%CI：0.99至6.5）相关。“典型”肺炎的临床和影像学特征对区分肺炎球菌性和非肺炎球菌性病因既不敏感也无特异性。这些结果支持基于病因与年龄、合并症和病情严重程度之间关联的管理方法，而非传统的CAP综合征方法。
