Standardization and monitoring of laboratory performance and quality assurance by use of the less-sensitive HIV incidence assay: seven years of results.

ABSTRACT

BACKGROUND: The Performance Evaluation Program for HIV-1 incidence tests provided quality assurance services to laboratories conducting the serological testing algorithm for recent HIV seroconversion by use of a modified less-sensitive version of the Vironostika HIV-1 MicroElisa System assay. We report on the performance of the assay using proficiency testing and quality control materials tested from 2001 to 2008. METHODS: Two sets of 5 blinded serum panels using common calibration and quality control materials were tested. The mean, standard deviation, and coefficient of variation were calculated. Results were analyzed for misclassifications false recent HIV infection errors (long-term infection classified as HIV infection less than 1 year), false long-term infection errors (HIV infection less than 1 year classified as long-term infection), and differences in standardized optical density means and variances over time. RESULTS: The false recent error rate was 1.26% (n = 2219). The false long-term error rate was 0.25% (n = 1618). No significant trends were observed for misclassification rates by year, and no significant trend in the standardized optical density over 7 years was observed. CONCLUSIONS: Laboratories using the less-sensitive Vironostika HIV-1 assay produced consistent results by use of a common calibrator and quality control materials.