Division of Microbiology, Kanagawa Prefectural Institute of Public Health, Kanagawa, Japan.
PLoS One. 2010 Feb 23;5(2):e9382. doi: 10.1371/journal.pone.0009382.
Prenatal human immunodeficiency virus (HIV) testing is essential for the prevention of mother-to-child transmission. However, false-positive results of screening testing are a concern as they may cause unnecessary emotional stress to pregnant women waiting for confirmatory test results. In regions with an extremely low prevalence, the positive predictive values of screening are unacceptably low rate. Here, we propose a HIV screening algorithm consisting of serial two fourth-generation enzyme immunoassays to reduce the number of false-positive screening results.
METHODOLOGY/PRINCIPAL FINDINGS: When 6461 pregnant women presenting to two maternity hospitals located in the Tokyo metropolitan area of Japan from September, 2004 to January, 2006 were tested using Enzygnost HIV Integral as a first screening test, 27 showed positive reactions. When these positive reaction samples were tested using VIDAS HIV DUO Quick as a second screening test, only one of them had a positive reaction, and the remaining 26 were nonreactive. Confirmatory Western blots and nucleic acid amplification test also showed that one was positive and the remaining 26 were negative; the subject who was positive with the confirmatory tests was identical to the subject who was positive with the second screening test. Thus, by adding the second screening test, the false-positive rate was improved from 0.4% to 0%, and the positive predictive value from 3.7% to 100%, compared with the single screening test.
By applying our serial screening algorithm to HIV testing in maternity hospitals, many uninfected pregnant women would not need to receive confirmatory tests and be subjected to emotional turmoil while waiting for their confirmatory test results. This algorithm would be suitable for HIV testing of pregnant women living in low prevalence regions such as Japan.
产前人类免疫缺陷病毒（HIV）检测对于预防母婴传播至关重要。然而，筛查检测的假阳性结果令人担忧，因为它们可能会导致等待确认性检测结果的孕妇产生不必要的情绪压力。在流行率极低的地区，筛查的阳性预测值的准确率非常低。在这里，我们提出了一种 HIV 筛查算法，包括连续两次第四代酶联免疫吸附试验，以减少假阳性筛查结果的数量。
方法/主要发现：2004 年 9 月至 2006 年 1 月，我们对日本东京都地区的两家妇产科医院的 6461 名孕妇进行了 Enzygnost HIV Integral 检测，作为初次筛查试验，其中 27 例显示阳性反应。当这些阳性反应样本用 VIDAS HIV DUO Quick 进行二次筛查试验时，只有一例呈阳性反应，其余 26 例呈阴性反应。确认性 Western 印迹和核酸扩增试验也显示其中一例为阳性，其余 26 例为阴性；经确认试验呈阳性的对象与经二次筛查试验呈阳性的对象相同。因此，通过添加二次筛查试验，假阳性率从 0.4%提高到 0%，阳性预测值从 3.7%提高到 100%，与单次筛查试验相比。
将我们的连续筛查算法应用于妇产科医院的 HIV 检测，可以使许多未感染的孕妇无需接受确认性检测，避免在等待确认性检测结果时产生情绪波动。该算法适用于流行率较低的地区，如日本的孕妇 HIV 检测。
