Abstract：
Toxoplasma gondii is a paradigmatic zoonotic parasite from the One Health perspective, since it is broadly distributed and virtually infects all warm-blooded species. A wide variety of serological techniques have been developed to detect T. gondii infection in humans and animals. Our aim was to describe and compare the main characteristics of these serological tests and validation processes and to critically analyze whether these tests meet the standards required to ensure an accurate serological diagnosis. The current systematic review and meta-analysis included 134 studies that were published from 2013 to 2023. QUADAS 2 tool was used to evaluate the quality of the included studies. A total of 52 variables related to the characteristics of the techniques and analytical and diagnostic validation parameters were studied. A wider panel of tests was developed for humans, including techniques exclusively developed for humans that involve costly equipment and the measurement of different Ig isotypes that are considered biomarkers of congenital toxoplasmosis. Studies conducted in humans frequently employed commercial techniques as reference tests, measured different immunoglobulin isotypes with a predominance for IgG (>50%) and discriminated between acute and chronic infections. In animals, the most commonly used reference techniques were in-house tests, which almost exclusively detected IgG. Common limitations identified in a large number of studies were some misunderstandings of the terms \"gold standard\" and \"reference test\" and the absence of information about the negative and positive control sera used or the exact cutoff employed, which were independent of the quality of the study. There is a lack of analytical validation, with few evaluations of cross-reactivity with other pathogens. Diagnostic odds ratio values showed that indirect ELISA based on native or chimeric antigens performed better than other tests. The reproducibility of serological test results in both humans and animals is not guaranteed due to a lack of relevant information and analytical validation. Thus, several key issues should be considered in the future, including interlaboratory ring trials.
摘要：
从“一个健康”的角度来看，弓形虫是一种典型的人畜共患寄生虫，因为它分布广泛，几乎感染所有温血物种。已经开发了多种血清学技术来检测人和动物中的弓形虫感染。我们的目的是描述和比较这些血清学测试和验证过程的主要特征，并严格分析这些测试是否符合确保准确血清学诊断所需的标准。目前的系统评价和荟萃分析包括2013年至2023年发表的134项研究。采用QUADAS2工具评价纳入研究的质量。研究了与技术特征以及分析和诊断验证参数相关的总共52个变量。为人类开发了更广泛的测试小组，包括专门为人类开发的技术，涉及昂贵的设备和不同的Ig同种型的测量，被认为是先天性弓形虫病的生物标志物。在人类中进行的研究经常采用商业技术作为参考测试，测量不同的免疫球蛋白同种型，IgG占优势（>50％），并区分急性和慢性感染。在动物中,最常用的参考技术是内部测试，几乎只检测到IgG。在大量研究中发现的常见限制是对术语“金标准”和“参考测试”的一些误解，以及缺乏有关所用阴性和阳性对照血清或所用确切截止值的信息。这与研究的质量无关。缺乏分析验证，很少评估与其他病原体的交叉反应性。诊断比值比值表明，基于天然或嵌合抗原的间接ELISA比其他测试表现更好。由于缺乏相关信息和分析验证，无法保证人和动物的血清学测试结果的可重复性。因此，今后应该考虑几个关键问题，包括实验室间环形试验。
