Journal of clinical microbiology 2017 04 19() pii 10.1128/JCM.00431-17
The Hologic Aptima HIV-1 Qualitative RNA assay was used in a rigorous screening approach designed to identify individuals at the earliest stage of HIV-1 infection for enrollment into subsequent studies of cellular and viral events in early infection (RV217/Early Capture HIV Cohort – ECHO Study). Volunteers at high risk of HIV-1 infection were recruited from study sites in Thailand, Tanzania, Uganda and Kenya with high HIV-1 prevalence rates among the populations examined. Small volume blood samples were collected by finger-stick at twice-weekly intervals and tested by Aptima. Participants with reactive Aptima test results were contacted immediately for entry into a more comprehensive follow up schedule with frequent blood draws. Evaluation of the Aptima test prior to use in this study, showed a detection sensitivity of 5.5 copies/ml (50%), with all major HIV-1 subtypes detected. A total of 54,306 specimens from 1,112 volunteers were examined during the initial study period (Aug 2009 to Nov 2010); 27 individuals were identified as converting from uninfected to infected status. Sporadic reactive Aptima signal was observed in HIV-1 infected individuals under antiretroviral therapy. Occasional false reactive Aptima results in uninfected individuals, or non-reactive results in HIV-1 infected individuals not on therapy were observed and used to calculate assay sensitivity and specificity. The sensitivity and specificity of the Aptima assay were 99.03% and 99.23%, respectively; Positive and Negative Predictive Value of 92.01 and 99.91%, respectively Conversion from HIV-1 uninfected to infected status was rapid, with no evidence of a prolonged intermittent low level viremia period.