Paediatric HIV Diagnostic Syndicate, Wits Health Consortium, 8 Blackwood Avenue, Parktown, Johannesburg, South Africa.
J Clin Virol. 2010 May;48(1):40-3. doi: 10.1016/j.jcv.2010.02.006. Epub 2010 Mar 7.
More routine laboratories in South Africa are equipped to perform quantitative than qualitative HIV viral detection assays. The accessibility of early infant diagnosis would be improved if a quantitative viral load (VL) assay performed on dried blood spots (DBS) could accurately diagnose HIV-infection. The VL assay routinely used in the country has not previously been assessed on DBS for early infant diagnosis.
To determine the accuracy of the NucliSens EasyQ assay (bioMerieux, Lyon, France) on DBS for early infant diagnosis of HIV in a subtype C-infected population.
Stored DBS samples collected from children presenting for HIV testing were analyzed. DBS EasyQ VL results were compared to the child's HIV status as determined by a whole blood HIV DNA PCR result.
The EasyQ assay was performed on 235 stored DBS samples from 71 HIV-infected and 164 HIV-uninfected children. Of the 216 infants (children aged 12 months or less) tested, all 52 HIV-infected infants were detected (sensitivity of 100%). Six of 164 HIV-uninfected infants yielded false positive results (specificity 96.3%). All false positive and six of the true positive infants had VL<3.7 log IU/ml. These 12 (5.6%) infants would require repeat testing to differentiate true from false positives. Using a threshold above 3.7 log IU/ml (equivalent to 4 log copies/ml) to define a positive result would yield an accurate diagnosis in 204 (94.4%) infants.
DBS EasyQ VL assays provide an accurate option for early infant diagnosis in low resource settings.
南非更多的常规实验室能够进行定量而不是定性 HIV 病毒检测分析。如果能够通过对干血斑（DBS）进行定量病毒载量（VL）检测来准确诊断 HIV 感染，那么早期婴儿诊断的可及性将会提高。该国有常规使用的 VL 检测方法以前并没有在 DBS 上进行过早期婴儿诊断的评估。
确定 NucliSens EasyQ 检测法（生物梅里埃，里昂，法国）在检测 C 亚型 HIV 感染的儿童时在 DBS 上用于早期婴儿诊断 HIV 的准确性。
对送检进行 HIV 检测的儿童的储存 DBS 样本进行了分析。将 DBS EasyQ VL 结果与通过全血 HIV DNA PCR 结果确定的儿童 HIV 状态进行比较。
对 71 名 HIV 感染和 164 名 HIV 未感染儿童的 235 份储存 DBS 样本进行了 EasyQ 检测。在 216 名（12 个月或以下）接受检测的婴儿中，所有 52 名 HIV 感染婴儿均被检出（敏感性为 100%）。164 名 HIV 未感染婴儿中有 6 名出现假阳性结果（特异性为 96.3%）。所有假阳性和 6 例真阳性婴儿的 VL<3.7 log IU/ml。这 12 名（5.6%）婴儿需要重复检测以区分真阳性和假阳性。使用高于 3.7 log IU/ml（相当于 4 log 拷贝/ml）的阈值来定义阳性结果可使 204 名（94.4%）婴儿的诊断得到准确判断。
DBS EasyQ VL 检测法为资源匮乏环境下的早期婴儿诊断提供了一种准确的选择。
