太原地区社区获得性肺炎病原学调查以及军团菌感染状况研究

Pathogens of community-acquired pneumonia and infection with legionella in Taiyuan region

目的①对太原地区社区获得性肺炎(CAP)病原学特征进行流行病学调查研究,以了解病原微生物的感染特点、流行的优势菌株等。②探讨CAP的流行规律及影响因素。③探讨军团菌实验室检测方法。方法收集符合CAP诊断标准,同时排除肺结核、肺部肿瘤、非感染性肺间质性疾病、肺水肿、肺不张、肺栓塞、肺嗜酸性粒细胞浸润症、肺血管炎等疾病的277例患者。取患者急性期痰标本(咽拭子)和尿进行检测,同时收集流行病学基线资料。①细菌学检测:取患者急性期痰标本或咽拭子标本进行细菌培养,分离鉴定细菌;②军团菌检测:应用聚合酶链反应(PCR)扩增军团菌特异基因16SrRNA和尿抗原检测。结果①按照患者的年龄和职业构成,太原地区成人CAP的发病人群主要以老年人(58.7%)、工人(28.1%)、干部职员(18.9%)为主。②共收集了194份新鲜痰液进行了痰(咽拭子)培养的患者中,细菌培养阳性者171例,其中单一感染者105例,2种以上混合感染23例。前3位病原体依次为:白色念珠菌(10.8%)、肺炎链球菌(5.6%)、流感嗜血杆菌(4.1%),混合感染检出率为12.2%。太原地区肺炎链球菌合并奈瑟菌为主要的混合感染(2.5%)。病原体的分布与年龄、季节和基础疾病无关(P>0.05)。③对100例CAP患者进行尿抗原检测,阳性者9例(9.0%);PCR检测阳性者3例(3.0%)。军团菌肺炎发病人群多在50～80岁,且大多数患者工作和生活环境中有密闭的空调系统或有冷却塔、热水系统等。结论近年来太原地区CAP细菌感染占据首要地位。细菌感染以真菌、肺炎链球菌最多。白色念珠菌和肺炎链球菌是CAP最重要的病原菌;CAP的混合感染不容忽视;革兰阴性杆菌感染增多。

Objective ①To conduct an epidemiological survey on pathogens etiology of community-acquired pneumonia （CAP） in Taiyuan, so as to study the profiles of pathogenic microorganisms and dominant epidemic strains. ② To study the pattern of epidemiology and influential factors of community-acquired pneumonia. ③To explore the laboratory methods for detection of legionella infection. Methods Two hundreds and seventy seven patients with CAP were recruited. These patients fulfilled the diagnostic criteria of CAP and were excluded for other diagnosis such as pulmonary tuberculosis, lung tumors, non-infectious interstitial lung disease, lung edema, pulmonary atelectasis, pul-monary embolism, pulmanory eosinophilia and pulmonary vasculitis. Sputum （or throat swabs） and urine samples for detection during acute stage were collected, as well as baseline epidemiological data. ①Bacteriology detection： sputum samples or throat swabs were collected during acute stage for bacterial culture, isolation and identification. ②Legionel- la detection： Legionella-specific 16SrRNA gene was amplified by polymerase chain reaction （PCR）, and urine antigen was detected. Results ①CAP in Taiyuan was prevalent in the elderly （58.7%） by age, among workers （28.1%） and officials/clerks （18.9%） by occupation. ②Of the 194 fresh sputum samples or throat swabs for culture, 171 tested posi- tive in bacteria, including 105 infected with a single bacterium, 23 with at least 2 bacteria. The first three common pathogens were C albicans （10.8%）, S pneumoniae （5.6%） and H influenzae （4.1%）, and mixed infection was detected in 12.2% of the patients. The major combined infection in Taiyuan was Streptococcus pneumoniae and neisseriaceae （2.5%）. Distribution of pathogens was not shown to be correlated with age, season and underlying diseases （P0.05）. ③ Among 100 CAP patients undergoing tests for legionella, 9 （9.0%） were positive, including 3 （3.0%） by PCR detection. Legionella pneumonia was commonly found among the population aged between 50 and 80 years and most patients were working or living in a close environment with air conditioning, cooling tower or water heater. Conclusion Bacte-rial infection was a main source of CAP during the recent years in Taiyuan, with fungi and S pneumoniae as the main source of bacterial infections. C albicans and S pneumoniae were the most important pathogens. Mixed infection should not be overlooked as an etiology in CAP, with Gram-negative bacilli infection cases now on the rise.