Lu Ai-Zhen, Shi Peng, Wang Li-Bo, Qian Li-Ling, Zhang Xiao-Bo
Department of Respiratory, Children's Hospital of Fudan University, Shanghai 201102, China.
Department of Information Management, Children's Hospital of Fudan University, Shanghai 201102; Center for Evidenced-based Medicine, Fudan University, Shanghai 200032, China.
Chin Med J (Engl). 2017 Mar 20;130(6):647-651. doi: 10.4103/0366-6999.201595.
The accuracy of nasopharyngeal aspirate (NPA) specimens in detecting lower respiratory pathogens remains controversial. The objective of this study was to evaluate the diagnostic accuracy of aspirates (NPAs) specimen in lower respiratory tract infections (LRTIs) in children.
The prospective study was designed to collect the data of paired NPAs and bronchoalveolar lavage fluids from children with acute LRTIs from January 2013 to December 2015. All specimens were subjected to pathogen detection: bacterial detection by culture, Mycoplasma pneumoniae (Mp) detection by polymerase chain reaction assay and virus (influenza A and B viruses, parainfluenza virus [PIV] Types 1 and 3, respiratory syncytial virus, and adenovirus) detection by immunofluorescence assay. The diagnostic accuracy analysis of NPAs was stratified by age ≤3 years (n = 194) and >3 years (n = 294).
We collected paired specimens from 488 children. The positive rate of pathogen was 61.6%. For Streptococcus pneumoniae, NPA culture had the specificity of 89.9% and negative predictive value of 100% in age ≤3 years, the specificity of 97.2% and negative predictive value of 98.9% in age >3 years. For Mp, the positive predictive values of NPA was 77.4% in children ≤3 years, and 89.1% in children >3 years. For PIV III, NPA specimen had the specificity of 99.8% and negative predictive value of 96.5% in children ≤3 years. For adenovirus, NPA had the specificity of 97.8% and negative predictive value of 98.4% in age ≤3 years, the specificity of 98.9% and negative predictive value of 99.3% in age >3 years.
NPAs are less invasive diagnostic respiratory specimens, a negative NPA result is helpful in "rule out" lower airway infection; however, a positive result does not reliably "rule in" the presence of pathogens.
鼻咽抽吸物（NPA）标本在检测下呼吸道病原体方面的准确性仍存在争议。本研究的目的是评估抽吸物（NPA）标本对儿童下呼吸道感染（LRTIs）的诊断准确性。
这项前瞻性研究旨在收集2013年1月至2015年12月期间患有急性LRTIs的儿童的配对NPA和支气管肺泡灌洗液体的数据。所有标本均进行病原体检测：通过培养进行细菌检测，通过聚合酶链反应测定检测肺炎支原体（Mp），通过免疫荧光测定检测病毒（甲型和乙型流感病毒、1型和3型副流感病毒[PIV]、呼吸道合胞病毒和腺病毒）。NPA的诊断准确性分析按年龄≤3岁（n = 194）和>3岁（n = 294）分层。
我们收集了488名儿童的配对标本。病原体阳性率为61.6%。对于肺炎链球菌，NPA培养在年龄≤3岁时特异性为89.9%，阴性预测值为100%；在年龄>3岁时，特异性为97.2%，阴性预测值为98.9%。对于Mp，NPA在≤3岁儿童中的阳性预测值为77.4%，在>3岁儿童中为89.1%。对于PIV III，NPA标本在≤3岁儿童中的特异性为99.8%，阴性预测值为96.5%。对于腺病毒，NPA在年龄≤3岁时特异性为97.8%，阴性预测值为98.4%；在年龄>3岁时，特异性为98.9%，阴性预测值为99.3%。
NPA是侵入性较小的诊断性呼吸道标本，NPA结果为阴性有助于“排除”下气道感染；然而，阳性结果并不能可靠地“确诊”病原体的存在。
