Haeri Mazanderani Ahmad, Moyo Faith, Kufa Tendesayi, Maritz Jean, Sherman Gayle G
Centre for HIV & STIs, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa; Department of Medical Virology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.
Centre for HIV & STIs, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa; Paediatric HIV Diagnostics Syndicate, Wits Health Consortium, Johannesburg, South Africa; School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, South Africa.
Diagn Microbiol Infect Dis. 2018 Jul;91(3):248-255. doi: 10.1016/j.diagmicrobio.2018.02.019. Epub 2018 Mar 3.
We describe the extent of and variables associated with irreproducible HIV-1 PCR positive results within South Africa's Early Infant Diagnosis (EID) program from 2010 to 2015 and propose criteria for differentiating indeterminate from clearly positive results using the COBAS® AmpliPrep/COBAS® TaqMan HIV-1 Qualitative Test version 2.0 (CAP/CTM Qual v2.0). Fourteen percent of specimens with an instrument-positive result that were repeat-tested yielded a negative result for which cycle threshold (Ct) proved to be the only predictive variable. A Ct <33.0 was found to be the most accurate threshold value for differentiating clearly positive from irreproducible cases, correctly predicting 96.8% of results. Among 70 patients with an irreproducible positive result linked to a follow up HIV-1 PCR test, 67 (95.7%) were negative and 3 (4.3%) were instrument-positive. Criteria differentiating clearly positive from indeterminate results need to be retained within EID services and infants with indeterminate results closely monitored and final HIV status determined.
我们描述了2010年至2015年南非早期婴儿诊断（EID）项目中不可重复的HIV-1 PCR阳性结果的程度及相关变量，并提出了使用COBAS® AmpliPrep/COBAS® TaqMan HIV-1定性检测2.0版（CAP/CTM Qual v2.0）区分不确定结果与明确阳性结果的标准。14%仪器检测呈阳性的标本经重复检测后呈阴性，其中循环阈值（Ct）被证明是唯一的预测变量。发现Ct<33.0是区分明确阳性与不可重复病例的最准确阈值，能正确预测96.8%的结果。在70例与后续HIV-1 PCR检测相关的不可重复阳性结果的患者中，67例（95.7%）为阴性，3例（4.3%）仪器检测呈阳性。EID服务中需要保留区分明确阳性与不确定结果的标准，并密切监测结果不确定的婴儿，确定其最终HIV状态。
