Evaluation of a prototype Amplicor PCR assay for detection of human immunodeficiency virus type 1 DNA in blood samples from Tanzanian adults infectedwith HIV-1 subtypes A, C and D

Background: In previous evaluations, the standard Amplicor HIV-1 DNA PCR te st (Roche Diagnostic Systems) has been reported to have low sensitivity for the detection of some non-B HIV-1 subtypes. It has therefore become necess ary to determine the performance of commercially available as well as proto type HIV-1 PCR assays for HIV-1 DNA detection in samples from various geogr aphical settings, in order to assess their ability to detect the different HIV-1 genotypes. Objectives: To determine the performance of the prototype Roche Amplicor version 1.5 PCR test in comparison to that of the standard R oche Amplicor PCR test for the detection of HIV-1 DNA in blood samples from HIV-1 seropositive pregnant Tanzanian women infected with various HIV-1 su btypes. Study design: This was a cross-sectional study done on 161 blood sa mples collected from 106 HIV-1 seropositive and 55 seronegative asymptomati c pregnant women attending antenatal clinic in Dar es Salaam, Tanzania. Met hods: Cell pellets for PCR were prepared from EDTA blood by the Amplicor wh ole blood PCR sample preparation method. Plasma was used for HIV serology b y enzyme linked immunosorbent assays. Subtyping was done by the heteroduple x mobility assay (HMA) using cell pellets and/or plasma. Results: The sensi tivities of the prototype PCR and the standard assays were 99.1% (105/106) and 97% (99/102), respectively. All samples from 55 HIV-1 seronegative wome n were negative by both PCR assays. Among the 101 samples subtyped by HMA, 48 (47%) were subtype A, 30 (30%) subtype C, 20 (20%) subtype D and 3 (3%) were indeterminate. In the standard DNA PCR assay, a statistically signific antly higher proportion of subtype A samples had a low level of reactivity as measured as optical density compared with the subtypes C and D samples w hile in the prototype assay all three subtypes showed a high level of react ivity. Conclusions: The Amplicor version 1.5 DNA PCR test has a high sensit ivity for the detection of HIV-1 DNA in blood samples from Tanzanian adults . Since performance of this assay does not appear to, be influenced by diff erences in HIV-1 subtypes A, C and D, it has the potential for use in the d etection of HIV-1 DNA in samples from geographic areas where these subtypes are prevalent. (C) 2000 Elsevier Science B.V. All rights reserved.