Fifteen years of the proficiency testing program for HIV-1 viral load testing laboratories in China, 2005-2019

HIV-1 viral load (VL) testing is essential for monitoring the effects of antiretroviral therapy in HIV-infected patients. In order to identify factors that impact testing performance of HIV-1 VL testing laboratories, this study performed a retrospective analysis on data from the domestic HIV-1 VL proficiency testing (PT) program in China during 2005 to 2019.

Analysis was conducted on testing results of 155 PT panel specimens that were distributed to HIV-1 VL testing laboratories nationwide during 2005 to 2019. Follow-up on-site inspection records on unqualified laboratories were also analyzed.

By 2019, 267 HIV-1 VL testing laboratories in China enrolled in the national PT assessment. Overall, HIV-1 VL testing performance has been consistently good after 2012, with less than 5% of participants reporting an unqualified score. Unsatisfactory equipment conditions and poor laboratory administration were the two main reasons causing unqualified scores in the PT assessment. Interestingly, we found that HIV-1 VL testing laboratories had better performance in the CDC system than in hospitals. In analysis on the variance of specimen testing results by different assays, we found that variation in results existed across different assay platforms, and HIV-1 VL testing assays based on real-time PCR technology showed comparatively smaller inter-laboratory variability.

To maintain high performance in HIV-1 VL testing laboratories, it is important to strengthen laboratory management and preserve equipment conditions. Due to the variation of testing results among different assay platforms, we suggest using the same assay platform for longitudinal monitoring of patient viral load.