结核菌素皮试和全血γ干扰素测定对儿童结核病诊断准确性的研究

目的 评价结核菌素(PPD)皮试和全血γ干扰素(IFN-γ)测定试验诊断儿童结核病的准确性.方法 选择2006年7月至2010年4月首都医科大学附属北京儿童医院住院临床诊断结核和呼吸系统疾病的患儿为研究对象.根据患儿所暴露的结核感染危险因素分为5组:A组:无结核病密切接触史的非结核病的呼吸系统疾病患儿;B组:有活动性结核病患者密切接触史的非结核病的呼吸系统疾病患儿;C组:无结核病密切接触史的临床诊断结核病患儿;D组:有活动性结核病患者密切接触史的临床诊断结核病患儿;E组:病原学或病理学确诊的活动性结核病患儿.患儿于入院当日行PPD皮试,入院后1～7 d采集外周静脉血行全血IFN-γ测定.以敏感度、特异度、阴性预测值、阳性预测值和似然比评价PPD皮试和全血IFN-γ测定对结核病的诊断价值.结果 125例患儿进入分析.A组40例,B组11例,C组29例,D组27例,E组18例.①PPD皮试取硬结≥10 mm为阳性判断标准时,诊断结核病的敏感度为77.0%,特异度为70.6%;取硬结≥15 mm为阳性判断标准时,诊断结核病的敏感度为50.0%、特异度为80.2%;全血IFN-γ测定的敏感度为85.1%、特异度为94.1%.②PPD皮试取硬结≥10 mm为阳性判断标准诊断结核病时,<3岁患儿PPD皮试的敏感度和特异度均显著低于≥3岁患儿,城区和郊区患儿的敏感度和特异度接近;全血IFN-γ测定诊断结核病的敏感度和特异度在不同年龄、居住地间差异无统计学意义.③全血IFN-γ测定阳性率与结核感染暴露因素的相关性优于PPD皮试(取硬结≥10或15 mm为阳性判断标准时).结论 潜伏结核感染筛查时以硬结≥15 mm作为PPD皮试阳性判断标准,可提高诊断的特异度;临床疑似结核病的诊断以硬结≥10 mm作为PPD皮试阳性判断标准,可提高诊断的敏感度.全血IFN-γ测定诊断结核病的敏感度和特异度均较好.     

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目的探讨干扰素γ释放试验和结核菌素皮肤试验(PPD)在儿童结核病和潜伏结核感染诊断中的价值。方法检索1990年1月至2011年2月在PUBMED、MEDLINE、OVID、CNKI等数据库发表的有关文献,并追查相关文献的参考文献,对文献按照诊断试验的纳入标准进行筛选。采用敏感度和特异度作为诊断价值的评价指标。采用Meta-Disc1.4软件进行Meta分析。结果 QuantiFERON-TB GoldIn-Tube在确诊结核病和(或)临床诊断结核病患儿中的汇总敏感度为67%,在对照儿童中汇总特异度为91%;T-SPOT.TB在确诊结核病和(或)临床诊断结核病患儿中的汇总敏感度为57%,在对照儿童中汇总特异度为88%;PPD试验在确诊结核病和(或)临床诊断结核病患儿中的汇总敏感度为70%,在对照儿童中汇总特异度为43%。结论 PPD试验因受卡介苗接种的影响,特异度较低;而干扰素γ释放试验因不受卡介苗接种的影响而具有很高的特异度。干扰素γ释放试验可以有效筛查儿童潜伏结核感染,特别是在有卡介苗接种史及活动性密切接触史儿童中。     

小儿隐性结核感染最佳治疗方案探讨

全世界有20亿人口感染隐性结核,是世界范围内结核病流行的最危险根源。85%~90%新被诊断的活动性肺结核,系由PPD阳性的隐性结核感染(LTBI)演变而来。海地1例30岁妇女怀孕前2年PPD硬结直径20mm,胸片(-),无结核中毒症状,未按LTBI给予抗结核治疗。2年后产一男婴,出生44d后出现发热被诊为先天性结核病。母产前1周出现惊厥,诊为脑结核,母与其子均经结核菌检阳性证明为结核,因为母亲未及时治疗LTBI所致[1]。结核病防治最有效的措施是早期治疗LTBI,从而减少活动性结核病的发生[2,3]。美国公共健康服务机构采用随机对照选用INH治疗7万各种…     

酶联免疫斑点技术对小儿结核病的诊断价值

目的 探讨酶联免疫斑点技术(ELISPOT)对新疆地区小儿结核病的诊断价值.方法收集2006年10月-2007年12月新疆医科大学第一附属医院儿科2个月～14岁疑似结核病的115例患儿,采集外周静脉血,利用ELISPOT结核感染T细胞诊断试剂盒进行ELISPOT检测,同期行结核菌纯蛋白衍生物(PPD)试验,并进行全面临床评估,随访3～6个月,结合疗效进行最终诊断.对ELISPOT检测结果与最终确诊结果进行比较,计算其灵敏度、特异度,并与PPD试验作对比.分析不同年龄组(≤36个月龄及＞36个月龄)、有无并营养不良、是否为重症结核病、结核部位(肺结核或肺外结核)以及不同民族(维吾尔族、汉族)间ELISPOT检测与PPD试验阳性率的差异,及不同因素对ELISPOT试验和PPD试验结果的影响.结果ELISPOT诊断小儿结核病的灵敏度80%,特异度86%.ELISPOT试验阳性率显著高于PPD试验阳性率(P＜0.01).在结核病病例中,并营养不良组及重症结核病组PPD试验阳性率明显低于未并营养不良组及非重症结核病组(Pa＜0.05),而ELISPOT阳性率在各组间均无统计学差异(Pa＞0.05);＞36个月龄组与≤36个月龄组、维吾尔族组与汉族组、肺结核组与肺外结核组比较,无论ELISPOT试验还是PPD试验的阳性率均无统计学差异(Pa＞0.05).结论ELISPOT诊断小儿结核病敏感、快速,而且受营养不良、重症结核病因素的影响较小,对儿童结核病具有较高的诊断价值,可用于新疆地区小儿结核病的早期快速诊断.     

结核分枝杆菌多抗原蛋白芯片对儿童结核病的诊断价值

目的 探讨结核分枝杆菌(MTB)多抗原蛋白芯片对儿童结核病的诊断价值。方法 选取2005年4月至2006年4月在首都医科大学附属北京儿童医院诊断为结核病的住院患儿作为结核病组。选取同期住院，患感染性疾病，同时除外结核病的患儿作为非结核病组；选取体检纯化蛋白衍生物（PPD）试验阳性，既往无结核病史，无明显结核中毒症状，胸部影像学及腹部B超检查未见结核病灶的儿童作为结核感染组；选取同期行健康体检，卡疤试验阳性，无基础疾病，无结核接触史的儿童为健康对照组。各组留取血清标本。计算结核病组PPD试验阳性率及细菌学检查阳性率。应用MTB多抗原蛋白芯片同时检测标本中脂阿拉伯甘露糖（LAM）、相对分子质量16 000和38 000蛋白IgG抗体，通过蛋白芯片阅读仪判断结果，其中任意1种或1种以上抗体检测阳性，即判为蛋白芯片检测阳性。分别计算各组抗体检测阳性率，并计算该方法检测儿童结核病的灵敏度、特异度、阳性预测值和阴性预测值等指标。应用Logistic回归及χ2检验分析蛋白芯片检测阳性率与患儿年龄、病程、抗结核治疗时间、激素使用以及结核病类型的关系。结果 研究期间共纳入结核病组79例，非结核病组33例，结核感染组15例，健康对照组30例。蛋白芯片检测结核病组的阳性率为34.2%（27/79），低于PPD试验阳性率（84.8%，67/79），高于细菌学检查阳性率（12.7%，10/79）。在非结核病组阳性率为6.1%（2/33），结核感染组和健康对照组阳性率为0。蛋白芯片检测结核病组的灵敏度为34.2%，特异度为97.4%。阳性预测值93.1%，阴性预测值58.5%。Logistic回归发现蛋白芯片检测阳性率仅与病程相关，且随病程延长而阳性率升高。病程<1个月，蛋白芯片检测阳性率为18.8%（6/32），病程在～3个月，蛋白芯片检测阳性率为21.6%（8/37），病程>3个月，蛋白芯片检测阳性率为100%（13/13）。目前的统计结果尚未发现蛋白芯片检测阳性率与患儿年龄、抗结核治疗时间、激素使用情况有显著相关关系。结核病分型不同所造成的蛋白芯片检测阳性率的差异主要是由于其病程分布不同所致。结论 多抗原蛋白芯片对儿童结核病的诊断有一定价值，可作为一种诊断补充手段。但该方法灵敏度较低，不适用于早期诊断。     

支气管哮喘4～7岁患儿脉冲振荡肺功能异常与正常分界点的确定

目的探讨4~7岁哮喘患儿脉冲振荡肺功能(IOS)异常与正常值的分界点。方法选择正常患儿124例,发作期哮喘儿童160例,采用Mastscreen IOS肺功能仪进行IOS测定,计算IOS主要参数在不同预计值水平判断肺功能异常的敏感度与特异度。结果哮喘患儿IOS参数与正常儿童显著不同,以呼吸总阻抗(Zrs)≥115%正常预计值作为肺功能异常时,其对哮喘诊断的敏感度和特异度均为0.68;以总呼吸道黏性阻力(R5)≥115%正常预计值作为异常时,其敏感度和特异度则分别为0.61和0.63;而以电抗(X5)≥110%正常预计值作为异常时,其敏感度和特异度分别为0.84和0.81。结论对哮喘患儿进行IOS测试时,应将Zrs、R5≥115%正常预计值,X5≥110%正常预计值作为判断异常指标。     

基础生命体征对危重型手足口病的早期诊断价值

目的 探讨基础生命体征在早期识别危重型手足口病中的诊断价值。方法 收集2010 年1 月至2014 年8 月358 例重症手足口病患儿(2 期重型212 例, 3 期危重型146 例)的临床资料, 采用受试者工作特征(ROC)曲线分析峰热、热程以及不同年龄段心率(HR)、呼吸频率(RR)、收缩压(SBP)和舒张压(DBP)对诊断3 期(危重型)手足口病的价值。结果 0 岁~ 组患儿中, 当HR ≥ 148.5 次/min、RR ≥ 36.5 次/min、SBP ≥ 95 mm Hg、DBP ≥ 59 mm Hg, 提示手足口病患儿可能进展到危重型;1 岁~ 组患儿中, 当HR≥ 142.5 次/min、RR ≥ 31.5 次/min、SBP ≥ 103 mm Hg、DBP ≥ 60.5 mm Hg 时, 对诊断危重型手足口病有一定价值;≥ 3 岁组患儿中, 当HR ≥ 139 次/min、RR ≥ 29.5 次/min、SBP ≥ 103 mm Hg, 提示手足口病患儿可能进展到危重型;各指标敏感度均大于0.517, 特异度均高于0.769。手足口病患儿峰热AUC=0.507, 与AUC=0.5 比较差异无统计学意义(P=0.816);当热程≥ 5.5 d 时, 敏感度为0.589、特异度为0.571。结论 HR、RR 和BP 是早期识别危重型手足口病的良好指标, 识别的最佳临界点具有年龄特征, 峰热、热程及年长患儿DBP 对早期识别危重型手足口病的价值不大。     

儿童肺结核支气管肺泡灌洗液Xpert MTB/RIF检测的诊断准确性研究

目的探讨支气管肺泡灌洗液的Xpert MTB/RIF检测对儿童肺结核的诊断价值。方法有疑似活动性结核病的临床症状和体征，行纤维支气管镜检查并留取了支气管肺泡灌洗液的患儿为研究对象。以支气管肺泡灌洗液作为病原学检测标本，分别以病原学诊断活动性结核病和临床诊断活动性结核病为金标准，以Xpert MTB/RIF为待测标准，考察Xpert MTB/RIF对病原学和临床诊断结核的诊断价值。基于样本中结核分枝杆菌（MTB）的Ct值反映所检测样本中MTB的载量；通过对利福平耐药位点的检测，对MTB菌株进行药物敏感性检测。结果符合本文纳入标准的疑似结核病患儿351例，男198例，女153例，年龄（5.9±3.9）岁。肺结核患儿125例，其中病原学诊断结核43例（34.4%），临床诊断结核82例（65.6%）；肺结核合并支气管结核51例（40.8%），单纯肺结核74例（59.2%）；非结核呼吸道感染性疾病226例，肺炎支原体肺炎187例（82.7%），细菌性肺炎39例（17.3%）。Xpert MTB/RIF在病原学诊断和临床诊断结核的敏感度分别为79%(95%CI：63%~89%)和51%(95%CI：40%~62%)，差异有统计学意义（χ2=9.18，P=0.002）；肺结核合并支气管结核的敏感度为80%（66%~90%),单纯肺结核的敏感度47%(35%~59%)；病原学诊断和临床诊断结核、合并支气管结核和单纯肺结核特异度均为100%(95% CI：97.9%~100%)。Xpert MTB/RIF检测病原学诊断结核敏感度高于临床诊断结核，肺结核合并支气管结核敏感度高于单纯肺结核，差异有统计学意义（χ2=13.88，P<0.001）；支气管肺泡灌洗液的MTB核酸检出载量病原学诊断结核高于临床诊断结核，差异有统计学意义（χ2=7.37，P=0.025）。76例Xpert MTB/RIF检测阳性患儿中，利福平耐药2例（2.6%）。结论支气管肺泡灌洗液的Xpert MTB/RIF检测在儿童肺结核诊断中具有较高价值，可在缺乏细菌学诊断证据的临床诊断结核病儿童中发现MTB，具有较高的敏感度，有助于提高儿童结核病病原学检出率。     

警惕儿童结缔组织疾病合并结核感染

结缔组织病患儿本身存在多种免疫紊乱,大剂量皮质激素、免疫抑制剂的应用加重了细胞免疫缺陷,生物制剂进一步增加了结核感染的风险.结缔组织病合并结核感染临床表现复杂,有时很难鉴别是原发疾病活动还足结核感染.肺部影像学检查是临床诊断结核病的主要手段,QFT-G试验和T-SPOT.TB开辟了辅助诊断新途径.应详细询问结核接触史、卡介苗接种史,常规进行血清结核杆菌抗体检测及PPD皮试.临床高度提示结核感染者,应给予诊断性抗结核治疗.     

不同时段血清降钙素原浓度对新生儿早发细菌感染的诊治价值

目的：评估出生早期不同时段血清降钙素原(procalcitonin,PCT)对新生儿早发细菌感染的诊断和治疗价值。方法将195例有宫内感染高危因素的新生儿根据感染结局分为细菌感染组24例及非感染组171例,测定出生2h内,6~12h,12~36h及大于48h新生儿血清PCT、C-反应蛋白(C-reactive protein,CRP)及外周血白细胞含量,分析不同时段PCT诊断早发感染的敏感度、特异度,及其对疗效的判断。结果出生2h内细菌感染组PCT、CRP及白细胞阳性率比较差异均无统计学意义(P﹥0.05);出生6~12h当PCT以2ng/ml为阈值时,其诊断细菌感染的敏感度为91.7%,特异度为86.5%,较CRP及白细胞具有更高的敏感度;出生12~36h是PCT的生理性高峰期,不同阈值的PCT均不能同时有较高的敏感度及特异度,当PCT以0.5ng/ml、2ng/ml以及10ng/ml为阈值时,其敏感度分别为100%、91.7%及75.0%,特异度分别为5.8%、53.8%及95.9%。结论出生6~12h测定PCT,并且以2ng/ml为阈值时,对诊断早发细菌感染有较高的敏感度及特异度,尽量避开PCT的生理性高峰期(出生12~36h)测定PCT浓度,该时期诊断细菌感染的PCT阈值尚需进一步探讨。     

Use of purified protein derivative to assess the risk of infection in children in close contact with adults with tuberculosis in a population with high Calmette-Guérin bacillus coverage.

SETTING: Household contacts <15 years of age of adults with tuberculosis (TB) attending a reference center in Aracaju, Sergipe, Northeast Brazil. OBJECTIVE: To assess the use of purified protein derivative (PPD) and frequency of infection in children with high Calmette-Guérin bacillus (BCG) coverage who were recently exposed to TB. DESIGN: Cross-sectional study of 141 exposed household contacts <15 years of age and 506 nonexposed neighborhood controls. Children were examined and assessed for degree of exposure to index cases, BCG vaccination and scar and were tested with PPD. RESULTS: Exposed children were younger and less up to date in their vaccination schedule than controls (P < 0.05). BCG had been given to 95.6% of exposed children and 97.4% of controls, but only 80.9% of exposed vs. 88.5% of controls had a scar (P < 0.05). Scar sizes of exposed children were smaller (medians, 4.5 and 7 mm, respectively; P < 0.05). Children had lower weight for age z scores and height than the National Center for Health Statistics standards. Exposed children had lower weight for age z scores than controls (P < 0.05). Sixty-seven (47.5%) exposed children and 18 (3.6%) controls had PPD readings of >10 mm. Positivity and induration sizes increased with age, although this was significant only in the controls. The presence of a BCG scar was not associated with having a positive PPD. The degree of exposure was an important factor for PPD positivity; 66 (60.6%) of the 109 children with close exposure were positive compared with 1 (3.1%) of 32 with less intimate exposure. PPD indurations among close contacts were also larger than those with restricted exposure and controls (16.3, 11 and 9.4 mm, respectively; P < 0.05). PPD positivity was associated with the quantification of acid-fast bacilli in the adult; 38.5% of contacts with adults with sputum with (+) were positive, compared with 42.3% of those with (++) and 58.4% with (+++) (P < 0.05). CONCLUSION: PPD is a useful test to identify children infected with TB independently of whether they had received BCG or not. Children exposed to adults with TB are at high risk of infection. The risk of infection is associated with the intimacy of contact and the number of bacilli expectorated in sputum.     

Effect of number of BCG vaccination on tuberculin induration size

AIM: The aim of this study is to interpret purified protein derivative (PPD) induration sizes with respect to the number of Bacillus Calmette-Guérin (BCG) scars. METHODS: We have considered 1879 school children between the ages of 7 and 14 years from seven primary schools in Kocaeli, Turkey. Children were injected with 5TU 0.1 mL PPD and induration sizes were measured at 72 h. Number of BCG scars, PPD application dates and induration sizes were recorded for each pupil. This study was also evaluated further for 312 households. RESULTS: The mean diameter of PPD induration size for 0, 1, 2 and 3 BCG vaccination scars were 1.43 mm (95% confidence interval (CI): 0.84-2.02), 6.39 mm (95% CI: 5.91-6.87), 10.46 mm (95% CI: 10.04-10.88) and 11.35 mm (95% CI: 9.36-13.34), respectively. Furthermore, 90% and 95% percentiles of PPD induration 0, 1, 2 and 3 vaccinations were 10 and 12 mm, 16 and 19 mm, 17 and 19 mm and 19.2 and 20 mm, respectively. There was evidence for a linear trend across from 0 to 3 BCG vaccinations, indicating that mean induration size increases with the number of vaccination scars. The size of indurations directly correlated with the number of vaccination scars, PPD induration size of children with no vaccination scar was quite small and it was generally less than 5 mm. CONCLUSION: This study shows the importance of the number of BCG scars in the determination of PPD induration size limit when tuberculosis infection is evaluated.     

BCG revaccination and tuberculin reactivity

Interpretation of tuberculin reactions in revaccinated children is somewhat controversial among paediatricians. In this study, the effect of the number of BCG vaccines on tuberculin reactivity is evaluated. In 2810 healthy children aged 7 to 14 years with purified protein derivative (PPD) testing. Children were grouped according to the concordance of the number of the reportedJdocumented vaccinations to the number of scars. Group 1 and 2 comprised of children 7 to 10 years of age and 11 to 14 years of age respectively, who had non-concordant scar numbers, and Group 3 and 4 included 7 to 10 and 11 to 14 years old children with concordant scar numbers. Mean tuberculin induration sizes were 8.0±5.7 mm for Group 1,10.6 ± 4.9 mm for Group 2, 9.8 ± 4.9 mm for Group 3 and 10.9 ± 4 mm for Group 4. As the time interval after the last dose of vaccination increased, mean induration sizes decreased in Group 1 and Group 3. In contrast, the mean reaction sizes of Group 2 and Group 4 showed a positive correlation with the period after the last dose of vaccine. It seems advisable that an induration size> 15 mm should not be attributed to BCG vaccination in countries with a high tuberculosis infection prevalence and routine BCG revaccination policies. A detailed investigation for tuberculosis infection and disease should be performed in those cases.     

Interpretation of the tuberculin skin test in bacille Calmette-Guérin vaccinated and nonvaccinated school children

BACKGROUND: Our objective was to conduct a prevalence survey of purified protein derivative (PPD) reactions among Lebanese healthy school children to identify those with tuberculosis or latent tuberculosis and to investigate the effect of bacille Calmette-Guérin (BCG) vaccine on the interpretation of PPD reactivity. METHODS: A self-administered questionnaire, including demographic characteristics, time of prior BCG vaccine and number of doses, known household contact with tuberculosis as well as parents' characteristics and living conditions was administered. PPD testing was performed on all children in diverse Lebanese regions aged 3 to 19 years. Reactivity that measured <5 mm were considered negative induration, doubtful if between 5 and 9 mm and positive if 10 mm or above. Chest radiographs were obtained as part of the evaluation for children with positive induration. RESULTS: Of 4895 children, 4271 entered into the final data analysis. A total of 3259 children (76.3%) did not develop a reaction to PPD (0 mm), 170 (4%) had 1 to <5 mm reading, 509 (11.9%) had 5 to 9 mm and 333 (7.8%) had > or =10 mm. Approximately 62% of the vaccinated children had received BCG vaccine in first year of life. Two hundred ninety (61.8%) of 469 children < or =5 were vaccinated and 179 (38.2%) were not. Only 22 of the youngest vaccinated had positive PPD. Twelve children were diagnosed with tuberculosis, a prevalence of 280 per 100,000. However, the prevalence of latent tuberculosis was 7.51%. CONCLUSION: Our prevalence of tuberculosis and latent tuberculosis is a sentinel indicator of continued transmission in the community. The data support the current recommendations that children who receive BCG can and should be tested with PPD for latent tuberculosis and tuberculosis.     

Tuberculin test in the diagnosis of childhood tuberculosis: Analysis of quantitative and qualitative features

OBJECTIVE: To evaluate the role of the tuberculin test in the diagnosis of tuberculosis in children. METHODS: Test diagnosis study; Tuberculin test with PPD Rt 23 (2 UT) was performed in 158 children, distributed in 2 groups: 101 no tuberculous, BCG vaccinated children and 57 tuberculous ones (diagnosis by clinical-radiological and epidemiological features). The interpretation of the tuberculin test was made by quantitative analysis (Mantoux test) and qualitative analysis (Koch and Listeria phenomena). RESULTS: Using cutoff = 10mm in Mantoux test, we found sensitivity of 85.9% and specificity of 86.1%. The qualitative analysis (Koch phenomenon), showed sensitivity of 77.2% and specificity of 98%. CONCLUSION: The qualitative analysis of the tuberculin test was useful in the diagnosis of tuberculosis in children, associated to the Mantoux test interpretation.     

卡介苗接种对儿童结核病预防保护作用的探讨

目的：结核病的发病率近年有所回升,临床对结核病的治疗研究较多,但卡介苗接种后对机体的保护作用如何,持续时间长短,何时复种等研究不多。鉴于此,该文研究卡介苗接种对儿童的保护作用。方法：对该市城乡9608例0～14岁接种卡介苗(简称种卡)的儿童进行卡痕、PPD试验(结核菌纯蛋白衍化物)普查。结果：3个月～组小儿PPD阳性率最高,为 91.5%;1岁～ 组次之,为 81.6%;3岁～组最低,为 57.1%;7～14岁组PPD阳性率又有回升,为 74.2%,各组间差异有显著性(P<0.01)。城市儿童PPD阳性率为 78.8%,高于乡村儿童( 62.4%);卡痕阳性率为 90.3%,高于乡村儿童(56.1%),P<0.01;结核 自然感染率低于乡村儿童(1.7% vs 3.4%),P<0.05。<3岁儿童结核自然感染率最低(0.5%),低于3～7岁和7～14岁,7～14岁儿童自感率最高。结论：卡介苗对0～3岁儿童保护作用明显,对4岁以上儿童保护作用渐减弱;且城市儿童PPD阳性率和卡痕阳性率明显高于乡村儿童,说明种卡质量值得重视。     

Effect of zinc on the tuberculin response of children exposed to adults with smear-positive tuberculosis

The tuberculin test (PPD) is used frequently in the diagnosis of tuberculosis. PPD, however, relies on an intact cell-mediated immunity and infected children often have false negative results. This study assessed whether a single oral zinc supplement modifies the PPD induration size and its association with nutritional status in Brazilian children. Ninety-eight children below 15 years of age who had been exposed to adults with smear-positive pulmonary TB in 1998 were tested by PPD in 1998 and 2000. Children were randomised in 2000 to receive a single oral dose of zinc sulphate or a placebo at the time of administering the PPD. Forty-three (44%) children were PPD-positive in 1998 and 54 (55%) in 2000. A higher proportion of children were classified as PPD-positive in 2000 in the zinc-supplemented group (57.1%) than in the placebo group (53.1%). PPD indurations were larger in children receiving zinc (mean 18.5 and 15.5 mm in the zinc and placebo groups, respectively) (p < 0.03). Mean induration sizes in 2000 were larger in zinc-supplemented children, regardless of their nutritional status. Our study demonstrates that zinc increases the PPD induration size in children irrespective of nutritional state. Zinc supplementation could work by correcting asymptomatic or marginal zinc deficiencies or as a non-specific booster of immunological mechanisms (whether or not there is a deficiency).     

Risk factors for human immunodeficiency virus infection in Ethiopian children with tuberculosis.

BACKGROUND: Separate risk factors for HIV infection and for tuberculosis (TB) are well-studied, but it is unclear whether these risk factors still apply in the new epidemiologic situation of dual infection. This study examines risk factors associated with seropositivity for HIV in Ethiopian children with clinical TB. METHODS: A prospective, controlled study of children with TB diagnosed in Addis Ababa from December 11, 1995, to January 28, 1997, in which HIV-positive children were compared with HIV-negative children with regard to sociodemographic background, previous medical history and vaccination. RESULTS: HIV prevalence among children with clinical TB was 11.2%. High educational status of mothers, low age, loss of one or two parents and earlier Calmette-Guérin bacillus (BCG) vaccination of the child were factors independently related to HIV infection. CONCLUSION: Factors associated with HIV infection among children with clinical TB include higher education of parents, higher income and better living conditions. The HIV epidemic might thus modify traditional risk factors for tuberculosis. It might also decrease the overall effect of BCG vaccination given that BCG did not provide protection in children infected with HIV. An expected increase of dually infected children who are younger, more in need of hospitalization and often lacking one or both parents will put an additional burden on the Ethiopian health care system.     

血清结核杆菌抗体检测在呼吸道感染鉴别诊断中的意义

为探讨血清特异性结核抗体的辅助诊断价值和加强对小儿肺炎的鉴别诊断，采用酶联免疫吸附试验（ＥＬＩＳＡ）法，对１５７７例肺炎患儿、６８５例健康儿童及１１１例支气管淋巴结结核患儿进行了血清特异性结核抗体检测，用纯蛋白衍生物皮试作对照，肺炎组还作了结核杆菌ＰＣＲ检查。结果表明，结核组患儿的结核抗体阳性８４例（７５．７％），健康组儿童的结核抗体阳性２４例（３．５％），肺炎组的结核抗体阳性２６２例（１６．６％），肺炎组与健康组比较，ｕ＝８．６３，Ｐ＜０．０１。符合儿童结核诊断者３９例，占受检病例的２．５％，占结核抗体阳性病例的１４．９％。ＥＬＩＳＡ法的敏感性为０．７５７、特异性为０．９６５、符合率为０．９３６、阳性预测值为０．７７８、阴性预测值为０．９６１、精确性为０．７２２，９５％可信限为０．６１２～０．８３２之间。提示检测结核抗体有重要辅助诊断价值；肺炎患儿的结核感染率远高于健康组，故应高度警惕，在肺炎患儿中发现结核病患儿，并将其作为重点防治对象。     

Neonatal BCG vaccine and response to the tuberculin test in BCG vaccinated children in contact with tuberculosis patients in Recife, Brazil

This case-control study analyses the association between the tuberculin response and the neonatal BCG vaccine in 330 children under 15 who are home contacts of tuberculosis patients, taking into account risk factors for the transmission of infection. Interviews were conducted with 330 children, their parents or legal guardians. Chest X-rays were taken and the tuberculin test (TT) applied using 0.1 ml of PPD RT23, taking an induration reading of > or = 10 mm as the cut-off point for a positive test result. Prior BCG vaccination was ascertained by observing the presence of a scar on the deltoid region of the right arm. Six children were excluded because they had signs/symptoms of pulmonary tuberculosis, thereby reducing the final sample to 324 children. The multivariate analysis showed that being exposed to a patient with pulmonary lesions with cavities (OR = 3.14; CI: 1.59-6.20; p = 0.000), a positive sputum smear (OR = 3.65; CI: 1.52-8.78; p = 0.002) or a positive culture (OR = 4.42; CI: 1.39-14.1; p = 0.005), being under five (OR = 0.47; CI: 0.22-0.99; p = 0.045) are independently associated with a positive TT. The fact that a prior BCG scar is not associated with a positive response to the TT indicates the need to re-open discussion of the guidelines which exist in many poor countries where tuberculosis is still a serious public health problem. Such guidelines include those issued by the Brazilian Ministry of Health, which considers the child under 15 in contact with a tuberculosis case to be infected only if there is a TT of 10 mm or more and the child received no prior BCG vaccination.