肯尼亚感染曼氏血吸虫的儿童尿液样本中实时 PCR 检测的诊断性能：日常变化及吡喹酮治疗后的随访。

Diagnostic performance of Schistosoma real-time PCR in urine samples from Kenyan children infected with Schistosoma haematobium: day-to-day variation and follow-up after praziquantel treatment.

机构信息

Leiden University Medical Centre, Department of Parasitology, Centre of Infectious Diseases, Leiden, The Netherlands.

Division of Vector Borne Diseases, Ministry of Health, Nairobi, Kenya.

出版信息

PLoS Negl Trop Dis. 2014 Apr 17;8(4):e2807. doi: 10.1371/journal.pntd.0002807. eCollection 2014 Apr.

DOI:10.1371/journal.pntd.0002807

PMID:24743389

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC3990496/

Abstract

BACKGROUND

In an effort to enhance accuracy of diagnosis of Schistosoma haematobium, this study explores day-to-day variability and diagnostic performance of real-time PCR for detection and quantification of Schistosoma DNA compared to other diagnostic tools in an endemic area before and after treatment.

METHODOLOGY

Previously collected urine samples (N = 390) from 114 preselected proven parasitological and/or clinical S. haematobium positive Kenyan schoolchildren were analyzed by a Schistosoma internal transcribed spacer-based real-time PCR after 14 years of storage. Pre-treatment day-to-day fluctuations of PCR and microscopy over three consecutive days were measured for 24 children using intra-class correlation coefficient. A combined 'gold standard' (PCR and/or microscopy positive) was used to measure sensitivity and negative predictive value (NPV) of several diagnostic tools at baseline, two and 18 months post-treatment with praziquantel.

PRINCIPAL FINDINGS

All 24 repeatedly tested children were PCR-positive over three days with little daily variation in median Ct-values, while 83.3% were found to be egg-positive for S. haematobium at day 1 and 75.0% at day 2 and 3 pre-treatment, signifying daily fluctuations in microscopy diagnosis. Of all 114 preselected schoolchildren, repeated microscopic measurements were required to detect 96.5% versus 100% of positive pre-treatment cases by single PCR. At two months post-treatment, microscopy and PCR detected 22.8% versus 69.3% positive children, respectively. Based on the 'gold standard', PCR showed high sensitivity (>92%) as compared to >31% sensitivity for microscopy, both pre- and post-treatment.

CONCLUSIONS/SIGNIFICANCE: Detection and quantification of Schistosoma DNA in urine by real-time PCR was shown to be a powerful and specific diagnostic tool for detection of S. haematobium infections, with less day-to-day variation and higher sensitivity compared to microscopy. The superior performance of PCR before, and two and 18 months post-treatment provides a compelling argument for PCR as an accurate and reproducible tool for monitoring treatment efficacy.

摘要

背景

为了提高对埃及血吸虫的诊断准确性，本研究在流行地区，探索了实时聚合酶链反应（PCR）检测和定量埃及血吸虫 DNA 的日常变异性和诊断性能，与治疗前后的其他诊断工具进行了比较。

方法

对先前收集的 114 名经证实的寄生虫学和/或临床埃及血吸虫阳性肯尼亚学童的尿液样本（n=390）进行了分析，这些样本在经过 14 年的储存后，采用基于血吸虫内部转录间隔区的实时 PCR 进行了分析。对 24 名儿童连续三天进行了实时 PCR 和显微镜检测，测量了 14 天的日常波动，采用组内相关系数进行了测量。采用联合“金标准”（PCR 和/或显微镜阳性），在治疗前、治疗后 2 个月和 18 个月，对几种诊断工具的敏感性和阴性预测值（NPV）进行了测量。

主要发现

所有 24 名重复检测的儿童在三天内均为 PCR 阳性，中位数 Ct 值的日变化较小，而 83.3%的儿童在治疗前第 1 天和第 2 天和第 3 天发现埃及血吸虫虫卵阳性，表明显微镜诊断存在日常波动。在所有 114 名预先选定的学童中，重复的显微镜检测需要检测到 96.5%的治疗前阳性病例，而单次 PCR 则需要检测到 100%的阳性病例。在治疗后 2 个月时，显微镜和 PCR 分别检测到 22.8%和 69.3%的阳性儿童。根据“金标准”，PCR 的敏感性（>92%）明显高于显微镜（治疗前后均>31%）。

结论/意义：实时 PCR 检测尿液中的血吸虫 DNA 被证明是一种强大而特异的诊断工具，可用于检测埃及血吸虫感染，与显微镜相比，日常变化较小，敏感性更高。PCR 在治疗前、治疗后 2 个月和 18 个月的性能优势，为 PCR 作为监测治疗效果的一种准确、可重复的工具提供了有力的论据。