昆明地区2457例小儿急性下呼吸道感染病原学研究

Clinical and etiological analysis of 2457 pediatric cases with acute lower respiratory tract infections in Kun- ming regions

目的了解昆明地区不同年龄组小儿急性下呼吸道感染(ALRI)患儿细菌、呼吸道病毒感染病原谱及病原流行病学特点。方法对昆明地区2457例ALRI住院患儿,抽取鼻咽分泌物培养检测细菌病原;应用直接免疫荧光法进行呼吸道合胞病毒(RSV)、腺病毒(ADV)、流感病毒(IFA、B型)、副流感病毒(PIV1、2、3型)七种病毒抗原检测。结果2457例ALRI患儿标本中,检出阳性病原菌506株,阳性率20.6%(506/2 457);检出呼吸道病毒阳性病例587例,阳性率23.9%(587/2457);新生儿(出生～28d)、婴儿(～1岁)、幼儿(～3岁)、儿童(～18岁)组病原联检阳性率分别为56.6%、46.8%、41.7%、15.3%,呼吸道病原总阳性率44.5%(1093/2457);阳性病例中混合感染53例(婴儿49例),混合感染率4.8%(53/1093)。各年龄组细菌及病毒感染率比较差异均具有显著性(P<0.01)。细菌病原中革兰阴性菌占83.0%,前三位依次为大肠埃希杆菌、肺炎克雷白杆菌、阴沟杆菌;病毒病原中RSV占阳性病毒株的86.0%,其他病毒病原呈散在流行。两年中未检出IFA病毒株。昆明地区小儿ALRI细菌感染无明显季节性,呼吸道病毒感染具有明显季节性,高峰流行季节在每年7月至次年2月,流行季节持续近8个月,两年间夏季呼吸道病毒感染率存在差异。结论昆明地区各年龄组小儿ALRI的主要病原均以革兰阴性菌及RSV感染为主。年龄越小发病率及混合感染率越高;呼吸道病毒病原谱及流行季节存在地区差异。

Objective To analyze the clinical and etiological characteristics of pediatric patients with acute lower respiratory tract infection （ALRI） in Kunming region. ALRI pathogens were studied in order to determine pathogen distribution of different age groups. Methods Nasal secretion samples were collected from 2 457 ALRI cases for pathogen identification. Viral antigens were detected by direct and indirect immunofluorescent analyses. Results Five hundred and nine cases of 2 457 patients were detected bacterial infection positive （20.6%） ;587 cases were viral infection positive （23.9%）. Infection rates were 56.6%, 46.8%, 41.7 % and 15.3% among neonates（ - 28 d）, infants（ - 1 year）, toddlers（ - 3 years）, elderly children groups （ - 18 years） respectively. Mixed infections were found in 53 cases （4.8 % ）. There was statistical significance among different age groups mentioned above（P 〈 0.01 ）. Bacterial pathogens identified from the 506 samples mainly consisted of the Gram-negative bacteria （83.0 % ） with the top three pathogens of E. coli, Klebsiella pneumoniae and Bacterium cloacae. Of 587 samples, 550 samples were tested positive for the respiratory syncytial virus （ RSV ） antigen, accounting for 86.0 % of the total respiratory virus antigens-positive samples. No samples detected positive for influenza A virus （IFA） during recent two years. Conclusion Gram-negative bacteria and respiratory syncytial virus were two main pathogens responsible for ALRI in children in Kunming region. Infection incidence decreases with age. Pathogen spectrum and seasonal distribution vary regionally.