Diagnostic Accuracy of the InBios Scrub Typhus Detect Enzyme-Linked Immunoassay for the Detection of IgM Antibodies in Northern Thailand.
Diagnostic Accuracy of the InBios Scrub Typhus Detect Enzyme-Linked Immunoassay for the Detection of IgM Antibodies in Northern Thailand.
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DOI：
10.1128/cvi.00553-15
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发表时间：
2016-02
期刊：
影响因子：
--
通讯作者：
Paris DH
中科院分区：
文献类型：
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作者：
Blacksell SD;Tanganuchitcharnchai A;Nawtaisong P;Kantipong P;Laongnualpanich A;Day NP;Paris DH
在这项研究中，我们检查了InBios恙虫病IgM检测酶联免疫吸附试验（ELISA）的诊断准确性，并确定了最佳的诊断光密度（OD）临界值的筛选和诊断应用的基础上，前瞻性收集，表征样本未分化的发热性疾病患者在北方泰国。与血清学金标准，间接免疫荧光试验（IFA）的直接比较，发现ELISA OD值和IFA IgM滴度的强统计相关性。与先前针对泰国所述的对应IFA倒数滴度400相比，确定用于血清流行病学或筛选目的的最佳ELISA截止值为0.60 OD，其对应于84%的灵敏度（Sn）和98%的特异性（Sp）。对改进的和更严格的恙虫病感染标准（STIC），校正低假阳性IFA滴度的诊断性能，导致在0.5 OD的ELISA截止值的Sn为93%，Sp为91%。该诊断性ELISA截止值对应于1，600至3，200的IFA倒数滴度，这大大降低了与低阳性IFA滴度相关的假阳性率。这些数据是一致的，最近改进的血清学诊断阳性标准，使用贝叶斯潜在类建模方法。总之，InBios恙虫病IgM检测ELISA是负担得起的，易于使用，具有足够的诊断准确性的筛查和诊断目的，并应被视为一个改进的替代金标准IFA急性诊断。为了更广泛的应用，应考虑区域截止验证和抗原组成，以确保一致的诊断准确性。
In this study, we examined the diagnostic accuracy of the InBios Scrub Typhus Detect IgM enzyme-linked immunosorbent assay (ELISA) and determined the optimal diagnostic optical density (OD) cutoffs for screening and diagnostic applications based on prospectively collected, characterized samples from undifferentiated febrile illness patients in northern Thailand. Direct comparisons with the serological gold standard, indirect immunofluorescence assay (IFA), revealed strong statistical correlation of ELISA OD values and IFA IgM titers. Determination of the optimal ELISA cutoff for seroepidemiology or screening purposes compared to the corresponding IFA reciprocal titer of 400 as previously described for Thailand was 0.60 OD, which corresponded to a sensitivity (Sn) of 84% and a specificity (Sp) of 98%. The diagnostic performance against the improved and more-stringent scrub typhus infection criteria (STIC), correcting for low false-positive IFA titers, resulted in an Sn of 93% and an Sp of 91% at an ELISA cutoff of 0.5 OD. This diagnostic ELISA cutoff corresponds to IFA reciprocal titers of 1,600 to 3,200, which greatly reduces the false-positive rates associated with low-positive IFA titers. These data are in congruence with the recently improved serodiagnostic positivity criteria using the Bayesian latent class modeling approach. In summary, the InBios Scrub Typhus Detect IgM ELISA is affordable and easy-to-use, with adequate diagnostic accuracy for screening and diagnostic purposes, and should be considered an improved alternative to the gold standard IFA for acute diagnosis. For broader application, regional cutoff validation and antigenic composition for consistent diagnostic accuracy should be considered.