[Effect of laboratory referencing on data analysis of community viral load in HIV positive MSM from 15 cities, China]

Objective: To compare the community viral load (CVL) among MSM in 15 cities in China using standardized national reference sources. Methods: The study analyzed the existing database of National Major Science and Technology Project of China. The database was established with serial random survey of MSM HIV CVL among MSM in 15 cities from 2013 to 2015. VL tests were conducted in 15 laboratories with different equipment and methods, including RT-PCR, nucleic acid sequence based amplification (NASBA), branched DNA testing (bDNA) and Abbott M2000 RealTime system (M2000). Based on proficiency test for 15 laboratories conducted by National HIV Reference Laboratory, VL test values detected with EasyQ, bDNA and M2000 were converted and standardized into resultant values of TaqMan 2.0. Software SPSS 17.0 was used to produce descriptive statistics for the dataset. Results: From 2014 to 2015, the 15 testing sites were found to use a number of different viral load detection techniques. In 2014, the community viral load values were (2.38±1.47) and (2.99±1.31) in 15 testing sites, while in 2015 these values were found to be (2.07±1.34) and (2.72±1.19). The measurement of community VL was done using standard benchmarks of ≤200 copies/ml, ≤400 copies/ml and ≤1 000 copies/ml, that were used for reference for now. Conclusion: It is necessary to use standard detection method to improve the comparability of annual results. Using a standardized rate of ≤400 copies/ml or ≤1 000 copies/ml for successful control of VL was found with high stability for the result comparison among different areas.