Evaluation on clinical performance of a multiplex nucleic acid detection kit RespiFinder® 2SMART in detection of 12 viruses in respiratory tract infections

Objective To evaluate the performance of a commercial multiplex nucleic acid detection kit, i.e. RespiFinder® 2SMART kit in the pathogen detection of respiratory infections in clinical practice. Methods From May 2012 to May 2015, 471 nasopharyngeal swabs specimens collected from patients with acute febrile respiratory syndrome in Qinghai province were used as the research materials. The single tube multiplex nucleic acid detection kit, i.e. RespiFinder® 2SMART kit and the self-made methods established in the laboratory were used in parallel to detect 12 viruses. The consistency rates of both methods were analyzed. The samples with discordant results were analyzed by nested PCR and sequencing or by fluorescent quantitative PCR with single set of primers. The performance of the kit was evaluated by accessing positive predictive value, negative predictive value, sensitivity, specificity and Youden's index of the kit with the results by the self-made methods as reference values. Results The consistency rates for all targeted viruses between the two methods were higher than 95.00%. For the samples with discordant results (10.20%, 48/471), the positive results of HCoV-229E, HAdV and HRV/HEV by the kit (38.00%, 23/48) were confirmed to be correct. Using the results by the self-made methods as reference values, the positive predictive values and negative predictive values of the kit were 100.00% for most targeted viruses while the positive predictive values were relatively low for HCoV-229E (50.00%, 95%CI: 2.56-97.44) and HAdV (87.93%, 95%CI: 77.13-94.03). Both sensitivities and specificities of the kit were 100% for most targeted viruses while the sensitivities were low for PIV-1 (58.33%, 95%CI: 31.95-80.67), PIV-2 (57.14%, 95%CI: 99.17-100.00) and RSV-A (64.28%, 95%CI: 38.76-83.00). The Youden’s indexes of the kit for most targeted viruses were higher than 0.98 while the indexes of PIV-1, PIV-2, and RSV-A were 0.58, 0.57 and 0.64, respectively. Conclusions The RespiFinder® 2SMART kit demonstrated good performance in detection of HCoV, HMPV, HAdV, HRV, PIV-3 and RSV-B, but the sensitivity should to be improved for detection of PIV-1, PIV-2 and RSV-A. Key words: Respiratory virus; Multiplex nucleic acid detection; RespiFinder® 2SMART kit; Performance evaluation