Evaluation of factors contributing to variability of qualitative and quantitative proficiency testing for SARS-CoV-2 nucleic acid detection

• Published in: Biosafety and health Vol. 4; no. 5; pp. 321 - 329
• Main Authors: Zhang, Yongzhuo, Wang, Xia, Niu, Chunyan, Wang, Di, Shen, Qingfei, Gao, Yunhua, Zhou, Haiwei, Zhang, Yujing, Zhang, Yan, Dong, Lianhua
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.10.2022; Chinese Medical Association Publishing House. Published by Elsevier BV; Elsevier
• Subjects: Nucleic acid testing; Proficiency testing; Pseudovirus; Quality assessment; Reference material; SARS-CoV-2; Reference material; SARS-CoV-2; Quality assessment; Nucleic acid testing; Proficiency testing; Pseudovirus
• ISSN: 2590-0536; 2590-0536
• DOI: 10.1016/j.bsheal.2022.08.004

•Scientific question:•The COVID-19 epidemic continues to ravage the world. Therefore, various influencing factors in SARS-CoV-2 NAT and the significance of quantitative and qualitative detection capabilities deserve to be discussed, and several factors for improving testing capacity are proposed to provide guidance for containing the spread of the outbreak.•Evidence before this study:•Some institutions have carried out SARS-CoV-2 qualitative proficiency testing for domestic testing laboratories, and have raised issues such as insufficient overall testing capabilities and lack of personnel training. But there has been little discussion of quantitative capabilities and regulatory regimes.•New findings:•For quantitative capabilities, dPCR methods are more comparable and reliable, while qPCR results are easily affected by the use of standard materials and personnel operation. Quantitative competence is the basis for qualitative judgment. Participants from hospitals reported more satisfactory outcomes, while participants from businesses were less satisfied. The systems such as “CE” certification based on “self-declaration” are temporarily not suitable for China, and national supervision and the development of various verification projects play an important role in improving nucleic acid detection capabilities.•Significance of the study:•Not all laboratories have satisfactory results with SARS-CoV-2 testing, especially those from ICL. It is necessary to further improve its quality system, including selection of qualified testing kits, personnel training, standardized operations, daily quality control, and regular external assessments. Improving the overall testing capacity of the laboratory can greatly avoid the occurrence of testing errors and provide help for epidemic prevention and control. The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to unprecedented social and economic disruption. Many nucleic acid testing (NAT) laboratories in China have been established to control the epidemic better. This proficiency testing (PT) aims to evaluate the participants’ performance in qualitative and quantitative SARS-CoV-2 NAT and to explore the factors that contribute to differences in detection capabilities. Two different concentrations of RNA samples (A, B) were used for quantitative PT. Pseudovirus samples D, E (different concentrations) and negative sample (F) were used for qualitative PT. 50 data sets were reported for qualitative PT, of which 74.00% were entirely correct for all samples. Forty-two laboratories participated in the quantitative PT. 37 submitted all gene results, of which only 56.76% were satisfactory. For qualitative detection, it is suggested that laboratories should strengthen personnel training, select qualified detection kits, and reduce cross-contamination to improve detection accuracy. For quantitative detection, the results of the reverse transcription digital PCR (RT-dPCR) method were more comparable and reliable than those of reverse transcription quantitative PCR (RT-qPCR). The copy number concentration of ORF1ab and N in samples A and B scattered in 85, 223, 50, and 106 folds, respectively. The differences in the quantitative result of RT-qPCR was mainly caused by the non-standard use of reference materials and the lack of personnel operating skills. Comparing the satisfaction of participants participating in both quantitative and qualitative proficiency testing, 95.65% of the laboratories with satisfactory quantitative results also judged the qualitative results correctly, while 85.71% of the laboratories with unsatisfactory quantitative results were also unsatisfied with their qualitative judgments. Therefore, the quantitative ability is the basis of qualitative judgment. Overall, participants from hospitals reported more satisfactory results than those from enterprises and universities. Therefore, surveillance, daily qualitiy control and standardized operating procedures should be strengthened to improve the capability of SARS-CoV-2 NAT.