Comparison of the Abbott and Ortho enzyme immunoassays and cell culture for the detection of respiratory syncytial virus in nasopharyngeal specimens

A comparison of the Abbott Laboratories and the Ortho Diagnostic Systems Respiratory Syncytial Virus (RSV) Enzyme Immunoassays (EIA) and HEp-2 cell culture for the detection of RSV in 81 nasopharyngeal (NP) specimens from pediatric patients with lower respiratory tract infection was carried out. The sensitivity and specificity of the Abbott test compared to confirmed infection was 92.3% and 100.0%, respectively. The sensitivity and specificity of the Ortho test was 87.5% and 80.3%, respectively. We found the Abbott EIA test to be sensitive, specific, rapid, and easy to perform.     

Prolonged mechanical support in children with severe adenoviral infections: a case series and review of the literature

Adenovirus infections occur primarily in infants and children less than 5 years of age, accounting for 2% to 5% of respiratory illnesses in the pediatric population and 4% to 10% of childhood pneumonias. Although the majority of children with adenovirus disease develop mild upper respiratory tract disease, more severe disease may occur with involvement of the lower respiratory tract characterized by pneumonitis and/or small airways disease. The authors present a case series of 3 high-risk children with severe lower respiratory tract adenoviral infections. These cases demonstrate the potential for the development of severe respiratory involvement from adenovirus in infants and children with comorbid conditions and illustrate that there may be a rapid progression of the disease as well as the need, in selected circumstances, for prolonged mechanical support. We review the role of adenovirus in lower respiratory tract infections in infants and children, its potential to result in life-threatening complications in pediatric patients with comorbid conditions, and the potential life-saving role of mechanical ventilation and extracorporeal life support (ECLS) in these children.     

儿童腺病毒肺炎降钙素原变化分析

目的通过对比腺病毒肺炎及非腺病毒呼吸道病毒肺炎儿童、腺病毒普通肺炎患儿及腺病毒重症肺炎患儿血清降钙素原浓度水平,了解腺病毒肺炎儿童降钙素原变化规律。 方法选取 2015 年 1 月~2016 年 7 月期间在本院儿科住院治疗,诊断为小儿肺炎的患儿,先通过呼吸道病毒检测将患儿分组,检测腺病毒肺炎组及非腺病毒感染的呼吸道病毒肺炎组血清降钙素原浓度, 作两样本 t检验;然后把两组降钙素原升高阳性率作χ2 检验;最后把腺病毒肺炎组再分为普通腺病毒肺炎组及重症腺病毒肺炎组,将该两组降钙素原浓度作两样本 t检验。 结果腺病毒肺炎组及非腺病毒感染的呼吸道病毒肺炎组血清降钙素原浓度及降钙素原升高阳性率均有显著差异,腺病毒肺炎患儿降钙素原浓度（t=21.772,P=0.000)及降钙素原升高阳性率（χ2 =313.873,P= 0.000)均高于非腺病毒感染的呼吸道病毒组;普通腺病毒肺炎组及重症腺病毒肺炎组降钙素原浓度有显著差异（t =-11.190,P= 0.000),重症腺病毒肺炎组降钙素原浓度高于普通腺病毒肺炎组。 结论腺病毒肺炎儿童血清降钙素原较其他常见呼吸道病毒肺炎儿童明显升高,且重症腺病毒肺炎患儿降钙素原浓度明显高于普通腺病毒肺炎患儿,临床中诊治中或应引起重视。      

呼吸道感染9项病原体IgM抗体检测分析

目的对常见呼吸道感染（RTI）的9项病原体IgM抗体检测进行分析,探究一种快速、简捷、灵敏的方法。方法采用间接免疫荧光法对1151例患者进行嗜肺军团茵、肺炎支原体、Q热立克次体、肺炎衣原体、腺病毒（ADV）、呼吸道合胞病毒（RSV）、甲型流感病毒、乙型流感病毒、副流感病毒9项病原体IgM抗体进行检测。结果9项病原体IgM抗体在儿童组中阳性率为37．9％,以RSV感染多见;在成人组中阳性率为27．1％,以ADV感染多见。结论IF法是检测RTI病原体的一种具有高灵敏度和高特异性且操作简便的方法,适合临床实验室推广应用。     

2015年某医院儿童呼吸道感染病原学特征分析

目的：比较并分析甘肃省妇幼保健院儿童呼吸道感染常见病原体的检出情况,为临床准确诊断、合理治疗提供依据。方法收集2015年1～12月甘肃省妇幼保健院6032例急性呼吸道感染的患儿标本,采用免疫斑点试验技术检测其血清中6种常见呼吸道病原体早期特异性抗体IgM：腺病毒（ADV）、流感病毒（IV）、副流感病毒（PIV）、呼吸道合胞病毒（RSV）、肺炎支原体（MP）、肺炎衣原体（CP）。分析患儿感染模式,以及不同年龄、季节、性别等感染情况的差异。结果6032例感染的标本中有2279例阳性,阳性率为37．8％。6种呼吸道病原体的阳性率依次为：ADV12．2％、IV9．6％、CP7．9％、MP4．6％、RSV3．0％、PIV0．3％。呼吸道病原体检出率在春、夏季节较高;1～3岁和4～6岁组阳性率高。结论该院儿童呼吸道感染常见病原体以ADV为主,其次是IV,其感染具有明显的季节性;支原体和衣原体也是呼吸道感染常见病原体,主要有MP和CP。     

儿童医院内呼吸道感染病原菌与药物敏感性分析

目的：了解和分析儿童医院内呼吸道感染的病原菌分布及其耐药状况,为防控医院内感染提供科学依据。方法对396例医院内感染儿童患者送检的上呼吸道标本按常规方法进行微生物培养,并用 K-B 法测定细菌对临床常用抗菌药物的敏感性。结果396例上呼吸道标本中,有225例共分离出微生物234株,阳性分离率为56．8％（225/396）;分离出的234株病原菌中,革兰阴性菌的构成比为72．6％（170/234）,其中以克雷伯菌属的检出率最高,为49．4％（84/170）。革兰阳性菌的构成比为23．5％（55/234）,以葡萄球菌属的检出率较高,为58．2％（32/55）。234株病原菌对9种临床常用的抗菌药物敏感率较高的是亚胺培南,其次是氨基糖苷类。结论对儿童患者有感染症侯的有必要留取上呼吸道标本做细菌学检查和药物敏感性试验。     

儿童呼吸道感染患者金黄色葡萄球菌的分离与耐药性分析

目的 探讨和分析金黄色葡萄球菌在儿科呼吸道感染患者中的分离与耐药性变化,为指导临床用药控制感染提供依据。方法 采集2013年1月～2014年12月两年儿科(包括新生儿科)呼吸道感染患者痰液标本共5 413例,应用MicroScan-As4微生物自动鉴定分析仪对分离后的菌株进行鉴定和药物敏感试验,用Whonet5.6软件进行统计分析。结果 从儿科呼吸道感染患者标本中共分离出各种病原菌29种1 540株。其中金黄色葡萄球菌(S.aureus,SAU)336株(21.82%,336/1 540),超过总病原菌的1/5,在儿科呼吸道感染分离率占6.21%,显著高于其它病原菌分离率(除流感嗜血杆菌5%外,其余均<5%)。在所有检出SAU中耐甲氧西林金黄色葡萄球菌(MRSA)59株(17.56%,59/336),可以看出SAU在儿科呼吸道感染患者中占据首要位置。SAU对万古霉素、利奈唑胺、达托霉素、奎奴普丁这4种抗菌药物耐药率为0,对其它抗菌药物呈现不同程度耐药性; MRSA对青霉素、氨苄西林、苯唑西林、氨苄西林/舒巴坦、阿莫西林/克拉维酸、头孢唑林、头孢曲松耐药率为100%,对红霉素、克林霉素耐药率超过50%,对其它抗菌药物耐药性呈低耐药性。结论 儿童呼吸道感染SAU较多,尤其MRSA多重耐药现象严重。应加强对金黄色葡萄球菌耐药性监测,根据药敏试验结果进行个体化、合理化选用抗菌药物,有效控制和减少耐药菌株产生。     

实时荧光RT-PCR在人感染H7N9禽流感病毒检测中的应用

目的评估实时荧光逆转录聚合酶链反应（1it—PCR）检测H7N9禽流感病毒的应用效果,为人感染H7N9禽流感监测和防控提供可靠的实验室检测数据。方法采集各级医疗单位人感染H7N9禽流感监测及可疑病例标本137例,同时使用4种实时荧光RT-PCR试剂分别检测上呼吸道标本和下呼吸道标本中H7N9禽流感病毒核酸。结果H7N9禽流感病毒核酸阳性率为3．65％（5／137）;H7N9禽流感病毒核酸阳性标本中上呼吸道标本检出率为60％（3／5）,下呼吸道标本检出率为100％（3／3）。4种试剂符合率为100％。结论实时荧光RT—PCR能有效检出H7N9禽流感病毒核酸,检测下呼吸道标本有助于提高阳性检出率。     

Evaluation of new immunochromatographic assay kit for adenovirus detection in throat swab: Comparison with culture and real-time PCR results

A new immunochromatographic (IC) assay kit, BD Veritor System Adeno was evaluated to comparing with commercial available kit, BD Adeno Examan, cell culture, and real-time PCR using throat swab samples. Specimens were collected from 146 pediatric patients between July 2011 and January 2012.Mean age of patients was 4 years (8 months–15 years old). Patients were diagnosed with pharyngitis (n = 67), tonsillitis (n = 45), pharyngoconjunctival fever (n = 26), upper respiratory tract infection (n = 6), conjunctivitis (n = 1), or bronchitis (n = 1). Thirty-one of the patients (21.2%) had more than one disease.Among all samples, 61 (41.8%) were positive for adenovirus with BD Veritor System Adeno; 68 (46.6%) with BD Adeno Examan; 63 (43.2%) with real-time PCR; and 65 (44.5%) with cell culture. Serotype 3 (n = 41; 63.1%) was predominant among the 65 adenovirus isolates, followed by serotype 2 (n = 12; 18.5%), 1 (n = 6; 9.2%), 5 (n = 4; 6.2%), and 4 (n = 2; 3.1%). Relative sensitivity and specificity of BD Veritor System Adeno, BD Adeno Examan, and real-time PCR were 93.8% and 98.7%, 96.9% and 93.8%, and 96.9% and 100%, respectively. Positive predictive and negative predictive values for these methods were 98.4% and 95.1%, 92.6% and 97.4%, and 100% and 97.6%, respectively.The sensitivity and specificity of real-time PCR was greater than that of IC assay kits. However, IC assay kits also showed high sensitivity and specificity appropriate for clinical use.     

The uristatin dipstick is useful in distinguishing upper respiratory from urinary tract infections

BACKGROUND: We determined the diagnostic value of the trypsin inhibitor, uristatin, that is commonly found in urine and plasma in patients with infections or inflammations of any kind. METHODS: We collected urine specimens from patients with infections of the urinary or upper respiratory tract and from healthy controls. We also collected blood from patients with a likely upper respiratory tract infection and healthy controls. A bacterial count of >10(5) organisms/ml in urine was considered to represent infection rather than contamination. RESULTS: The uristatin dipstick test in urine showed acceptable negative predictive values (NPV of up to 93%) for patients without infection or inflammation. Here, the dipsticks could eliminate some urine cultures. For those with infection or inflammation, the positive predictive values (PPV) of the dipsticks were lower (up to 57%). Including the leukocyte esterase and nitrite values increased the PPV of the dipsticks for those with disease. CONCLUSIONS: The uristatin strip was more accurate than the leukocyte and nitrite dipsticks for predicting upper respiratory infections (URI) and C-reactive protein for those with infection or inflammation. The uristatin dipstick was able to detect both the bikunin and uristatin inhibitors.     

Neutrophil alkaline phosphatase activity in respiratory viral infection

Neutrophil alkaline phosphatase (NAP) is used as a diagnostic marker in several hematological disorders. In regard to the role of NAP in infectious diseases, previous investigators have presented the hypothesis that NAP activity is useful to distinguish viral infections from bacterial infections. Because the numbers of patients enrolled in previous studies of viral infections were limited, we intended to evaluate the hypothesis by measuring NAP activity in a large number of pediatric patients with respiratory viral infections. A cytochemical analysis of NAP was performed in 160 patients with various types of respiratory infections. In patients with adenovirus or respiratory syncytial (RS) virus infection, NAP activity was significantly higher than the control value newly established at our department, while in patients with Epstein-Barr virus, measles, or influenza infection, it was comparable to the control value. On an individual basis, NAP scores (determined from NAP cytochemical activity) in 22 of 26 patients (84.6%) with adenovirus infection, and 31 of 42 patients (73.8%) with RS virus infection were found to exceed the 95% confidence upper limit of the control group. In conclusion, NAP activity is quite varied among different respiratory viral infections. When NAP activity is high in respiratory infections, adenovirus or RS virus infection, as well as bacterial infections, should be taken into consideration.     

河北省南部地区住院患儿腺病毒呼吸道感染流行病学调查

目的 探讨河北省南部地区住院患儿腺病毒呼吸道感染的流行病学特点。方法 回顾性分析2017年3月至2021年2月于河北省儿童医院住院治疗的腺病毒呼吸道感染患儿的临床资料。结果 急性呼吸道感染住院患儿共32 682例,其中腺病毒感染2 356例,检出率为7.2%。腺病毒检出率在1岁～<3岁最高为12.4%;感染类型以支气管肺炎为主占47.3%;重症肺炎比率为12.4%。1月～<1岁患儿中重症肺炎占比最高,冬季重症肺炎占比最高(均P<0.05)。311株腺病毒进行了分型,共检出3种类型,分别是2型54例(17.4%)、3型146例(46.9%)、7型111例(35.7%);重症肺炎、死亡患儿均7型腺病毒检出比率最高(均P<0.05)。结论 河北省南部地区儿童急性呼吸道感染腺病毒检出率略高于全国水平,重症肺炎发生率较高。1月～<1岁、冬季发病、7型腺病毒感染、合并其他病原共感染的患儿易发生重症肺炎。     

儿童急性下呼吸道感染病毒感染的检测与分析

目的研究分析儿童急性下呼吸道感染病毒病原的构成特点。方法收集临床162例确诊急性下呼吸道感染病例的肺泡灌洗液,用试剂盒法进行病毒核酸提取和检测。结果162例急性下呼吸道感染病例中病毒感染阳性病例119例,阳性率73．5％。119例阳性病例中检出：流行性感冒病毒（IFV）3例、呼吸道合胞病毒（RSV）22例、腺病毒（ADV）4例、副流感病毒（PIV）46例、偏肺病毒（hMPV）17例、冠状病毒（COV）6例、博卡病毒（HBoV）20例。其中混合性感染47例,占29％,两种病毒混合感染38例,三种病毒混合感染8例,四种病毒混合感染1例。结论病毒是儿童急性下呼吸道感染的重要感染原因,患儿感染呈混合性感染趋势,两种病毒感染情况最多见。     

Evaluation of a rapid enzyme immunoassay system for serologic diagnosis of Mycoplasma pneumoniae infection

A 5-min qualitative membrane enzyme-linked immunoassay (EIA) from Remel (Mycoplasma pneumoniae immunoglobulin G (IgG)/IgM Antibody Test System) was evaluated for its ability to detect IgG and IgG at levels indicating active or recent infection. Specimens from 131 patients were evaluated using an immunofluorescent antibody assay (IFA) to determine IgG and IgM titers and the membrane EIA. An enzymelinked immunosorbent assay (ELISA) performed by a reference laboratory was used for discrepancy resolution. There were 34 IgM positive specimens (titer ⩾ 1:16), 19 IgG positive specimens (titer ⩾ 1:64), and 78 negative specimens. Compared with IFA and/or ELISA, the membrane EIA was 97% sensitive for the detection of IgM and 79% sensitive for the detection of IgG. Of the 78 specimens called negative, 17 specimens had IgG titers (⩽1:32) or an ELISA result indicating prior exposure, and the membrane EIA called seven of 17 (41%) positive. For the detection of both IgG and IgM, the membrane EIA had a sensitivity of 91 %, specificity of 91%, and positive and negative predictive values of 87 and 93%, respectively. The Remel membrane EIA is a rapid and reliable assay for the diagnosis of active or recent M. pneumoniae respiratory tract infections.     

Significance of the signal-to-cutoff ratios of anti-hepatitis C virus enzyme immunoassays in screening of Chinese blood donors

BACKGROUND: The correlation between signal-to-cutoff (S/CO) ratios of a second-generation hepatitis C virus (HCV) enzyme immunoassay (EIA; Abbott) and a third-generation HCV enzyme-linked immunosorbent assay (ELISA; Ortho) and confirmed HCV infection has been reported. The utility of the values for the Chinese anti-HCV EIA kits, however, has not been studied in evaluating test results in Chinese blood donors. STUDY DESIGN AND METHODS: A total of 156 donor samples repeat reactive for anti-HCV at routine screening from five representative regions of China were retested for anti-HCV by the Ortho third-generation HCV ELISA and six Chinese EIA kits and for HCV RNA by a human immunodeficiency virus-1 and HCV assay (Procleix, Chiron Corp.). The HCV RNA-nonreactive samples were further tested for anti-HCV by a third-generation recombinant immunoblot assay RIBA (Chiron Corp.). The positive result by either nucleic acid amplification test or RIBA was interpreted as confirmed HCV infection. RESULTS: The confirmed HCV prevalence rate in donors in five representative regions obtained in this study was 0.20 percent (77/37,900) in 2004. All seven anti-HCV EIA kits had a significant correlation between S/CO ratios and confirmed HCV infection. The threshold S/CO ratios, which predicted more than 95 percent of confirmed HCV infections for the Ortho, SABC, BGI-GBI, InTec, GWK, KHB, and WANTAI kits, were 3.8, 6.0, 7.0, 8.6, 10.0, 10.0, and 14.0, respectively. CONCLUSIONS: Anti-HCV EIA kits commonly used in Chinese donors screening demonstrate good correlation between S/CO ratios and the confirmed infection. For the Ortho third-generation HCV ELISA, the S/CO ratio of 3.8 determined by the US Centers for Disease Control and Prevention is applicable to Chinese blood donors. The Chinese domestic EIA kits evaluated show a diverse range of threshold S/CO ratios.     

儿科心脏重症监护病房患儿呼吸道感染病原菌的分布及耐药性研究

目的：探讨儿科心脏重症监护病房（CICU）呼吸道感染常见病原菌的分布及耐药情况,为临床合理选用抗菌药物提供参考。方法回顾性分析该医疗中心2011年1月至2012年12月1350例 CICU 下呼吸道感染患儿痰液标本培养及药敏检测结果。结果1350例痰标本中,共培养获得病原菌490株,其中革兰阴性杆菌288株（58．78％）,革兰阳性球菌140株（28．57％）,真菌62株（12．65％）。革兰阴性杆菌以肺炎克雷伯菌为主（62株,占12．65％）,其次为卡他布兰汉菌、铜绿假单胞菌、大肠埃希菌。大肠埃希菌和肺炎克雷伯菌中产超广谱β-内酰胺酶（ESBLs）菌株阳性率分别为73．33％和66．13％。革兰阳性球菌以金黄色葡萄球菌为主（65株,占13．27％）,其次为肺炎链球菌。耐甲氧西林金黄色葡萄球菌（MRSA）占24．62％。结论金黄色葡萄球菌、肺炎链球菌、肺炎克雷伯菌为 CICU 患儿呼吸道感染的主要病原菌,且存在多重耐药菌感染,根据病原菌种类及药敏结果合理应用抗菌药物是有效控制危重病患儿感染和减少耐药菌株产生的重要手段。     

2015年冬至2016年春儿童急性呼吸道感染病毒监测及分析

目的 调查2015年冬至2016年春在郑州大学第三附属医院儿科门诊急性呼吸道感染（ARI）患儿病毒病原学情况。方法 收集483例ARI患儿鼻咽部分泌物,采用多重媒介探针熔解曲线分析技术检测流感病毒A、B型,呼吸道合胞病毒A、B型,副流感病毒1~4型,鼻病毒,腺病毒,人偏肺病毒,冠状病毒,人博卡病毒和肠病毒。结果 病毒阳性检出率29.19%（141/483）,前4位依次为流感病毒8.49%、副流感病毒5.38%、呼吸道合胞病毒3.93%、鼻病毒2.90%,双重感染1.86%。29 d至6月龄婴儿病毒总检出率高于3~5岁及 6岁组,组间比较差异有统计学意义（2=7.068,P=0.008;2=6.810,P=0.009）,乙型流感病毒在1~2岁检出率最高,冠状病毒在29 d至6月龄者检出率最高,男性与女性病毒总检出率差异无统计学意义。呼吸道合胞病毒A型在急性下呼吸道感染阳性率为8.96%,与急性上呼吸道感染比较差异有统计学意义（2=9.042,P=0.003）;鼻病毒春季阳性率高于冬季,乙型流感病毒阳性率冬季高于春季,差异有统计学意义（2=4.999,P=0.025;2=6.876,P=0.009）,其他呼吸道病毒在冬、春季阳性率差异无统计学意义。结论 儿童ARI病毒阳性率与年龄、季节、感染状况有关,在调查期间流感病毒、副流感病毒、呼吸道合胞病毒和鼻病毒是儿童ARI的主要病毒病原。     

外周血C反应蛋白测定对儿童急性上呼吸道感染的诊断价值

[目的]探讨外周血C反应蛋白（CRP）在小儿急性上呼吸道感染中的诊断意义。[方法]采用前瞻性队列研究方法,选择2007年1～12月本院儿科首诊为急性上呼吸道感染的患儿271例,对患儿外周血白细胞计数（WBC）、中性粒细胞百分比（GB％）以及CRP分布情况进行统计分析,并研究抗菌药物治疗和预后之间的关系。[结果1271例患儿中,CRP〈8mg／L221例,CRP〉8mg／L50例,不同CRP情况下GB％的分布情况与其相近,两者间差异无显著性（P〉0．05）;血清cRP与GB％呈正相关（r=0．549,P〈0．01）;不同CRP情况下WBC均值不同,差异有显著性（P〈0．01）;未使用抗茵药物治疗组与使用组患儿5d内退热情况无显著性差异（P〉0．05）。[结论]外周血CRP含量的增高有助于临床对上呼吸道细菌感染的早期诊断,应作为常规项目推广,以减少抗菌药物的不合理使用。     

Comparison of two enzyme-linked immunosorbent assay (EIA) kits with immunofluorescence and isolation in cell culture for detection of respiratory syncytial virus (RSV)

Rapid diagnosis of respiratory syncytial virus (RSV) infections is based upon detection of viral antigen in cells obtained from the respiratory tract and usually employs immunofluorescence (IF) reactions or enzyme-linked immunosorbent assays (EIA). The Pathfinder EIA kit (Kallestad Diagnostics) was compared with the Abbott EIA kit by evaluating each against isolation of RSV in cell culture and detection of antigen by IF. The Pathfinder kit identified 116 of 129 culture-positive and 72 of 90 culture-negative specimens; the sensitivity was 90 percent and the specificity was 80 percent. The sensitivity of the Abbott EIA test compared to isolation of RSV in cell culture was 91% (115 of 127), and the specificity was 83% (74 of 89). Of 165 specimens evaluated by IF, the Pathfinder kit detected 97 of 105 IF-positive and 45 of 60 IF-negative specimens, giving a sensitivity of 92% and a specificity of 75%. The Abbott EIA compared similarly with IF, showing a sensitivity of 91% (98 of 108) and a specificity (42 of 54) of 78%. Visual reading of the Kallestad test resulted in a sensitivity of 92%, a specificity of 91%, positive predictive value of 95%, and negative predictive value of 86%. The Pathfinder EIA kit compared well with IF and the Abbott EIA for detection of RSV antigen but performed faster than the Abbott test and offers the option of a visual reading.     

宁波市江北区室外细颗粒物污染对儿科呼吸系统疾病的影响

目的探索室外细颗粒物（PM_2.5）对浙江省宁波市江北区儿科门诊患者呼吸系统疾病日门诊量的影响。方法收集2014 — 2017年江北区各医院儿科门诊患者资料及同期污染物浓度和气象资料，采用分布滞后非线性模型计算相对危险度。结果2014 — 2017年儿科门诊因呼吸系统疾病就诊984 941人次。 PM_2.5浓度较低时对儿科呼吸系统疾病日门诊量增加的效应增长缓慢，而在较高浓度时，累积效应随着浓度的增加快速上升。 同浓度PM_2.5的效应随着滞后天数的增加而减少。 不同浓度PM_2.5的滞后天数不同，最长可滞后20 d。 同一浓度PM_2.5对不同性别儿童的效应无差别，而对不同年龄儿童作用强度不同，3岁组和4 ~ 6岁组受到的效应最强。 在滞后10 d以前，各浓度PM_2.5更易引起急性上呼吸道感染，但在10 d之后，对慢性下呼吸道疾病的效应更强，且后者的滞后天数更长。结论PM_2.5浓度的升高会增加儿科呼吸系统疾病门诊就诊量，并存在滞后效应。 同一浓度PM_2.5对不同年龄段儿童造成的危害有差别，但在性别方面没有差别，PM_2.5在早期更易引起急性上呼吸道感染，但对慢性下呼吸道疾病的效应更持久。