cWe performed a comparative analysis between Roche Amplicor HIV-1 DNA test and CAPTAQ assay for the detection of HIV in 830 dried blood spot (DBS) pediatric samples collected in Mozambique. Our results demonstrated no statistical difference between these assays. The CAPTAQ assay approached nearly 100% repeatability/accuracy. The increased throughput of testing with minimal operator interference in performing the CAPTAQ assay clearly demonstrated that this method is an improvement over the Roche Amplicor HIV-1 DNA test, version 1.5.
Early infant diagnosis (EID) and immediate initiation of antiretroviral therapy are paramount to prevent AIDS-related deaths and to evaluate the effectiveness of prevention of mother-to-child transmission (PMTCT) programs (6,8,16,17). Currently, in most resource-poor settings with high burdens of HIV infections, a significant proportion of exposed infants do not have access to timely diagnosis of HIV. While it is necessary to seek simpler diagnostic assays for decentralization of testing, it is also urgent to increase the throughput of centralized testing to meet demand.The Roche Amplicor HIV-1 DNA test, version 1.5 (Roche Molecular Diagnostics, Branchburg, NJ), has been used by many diagnostic laboratories (13) for detection of HIV in dried blood spot (DBS) (1,10) samples. This assay has demonstrated high sensitivity and specificity (9). However, because this assay is performed manually, it has a low throughput in comparison with automated tests (3,4,5,14,15). In order to increase the testing capacity of Instituto Nacional de Saúde in Mozambique, where approximately 2,900 children were tested each month for HIV infections in 2010, we evaluated the performance of the Roche COBAS AmpliPrep/COBAS TaqMan (CAPTAQ) HIV-1 Qual test (Roche Molecular Diagnostics, Branchburg, NJ), which is an automated qualitative test for HIV detection in blood or DBSs (12). Eight hundred thirty country-wide pediatric (6 weeks to 9 months old) DBS samples that were consecutively received and tested for HIV by Amplicor assay in 2010 were subsequently tested using the CAPTAQ assay for comparison of results, following the manufacturer's recommendations (10, 12). Results of both assays are summarized in Table 1. A total of eight samples (0.96%) provided discordant results between the methods. All eight discordant samples were retested using the Amplicor assay, and results were identical to the initial testing. Unfortunately, insufficient DBS material was available to repeat the testing with the CAPTAQ assay.McNemar's test and Cohen's kappa statistic test were used to determine agreement between the two assays (7). Additionally, we calculated sensitivity and specificity of the CAPTAQ assay, as well as overall, positive, and negative indices of agreement, using the Amplicor assay as the gold standard method (2, 11). There was no evidence of statistically significant discordance between the two assays as shown by McNemar's test (Table 1). Additionally, the kappa statistic was 0.88 with a lower 95% confidence limit o...