Abstract：Objective To analyze the detection results of samples from influenza epidemic on campus detected by two commonly-used rapid detection reagents for influenza virus antigen, and to evaluate whether they are suitable for the diagnosis of influenza cases on campus. Methods Influenza-like illness (ILI) cases happened in the clustering epidemics on campus reported in Luohu District, Shenzhen City from September to December 2021 served as the research subjects. Three nasal/pharyngeal swabs were collected from each case for influenza virus nucleic acid test (quantitative fluorescence PCR assay) and influenza virus antigen rapid test (colloidal gold method) respectively. The sensitivity and specificity of the rapid antigen detection reagents and their consistency with quantitative fluorescence PCR assay were calculated. By comparing the overall detection rate, the detection rate of each epidemic and the threshold cycle (Ct) value of the detected samples, the detection effects of the rapid antigen detection reagents were analyzed. Results Thirty-eight clustering outbreaks of ILI were reported in Luohu District, Shenzhen City from September to December 2021. A total of 203 nasal/pharyngeal swab samples were collected, of which 140 (68.97%) were positive for influenza B virus. Most of the sampled subjects were elementary school students, with a median age of 8 years. The sensitivities of the two rapid detection reagents were 61.43% and 42.86%, respectively, and their specificities were 96.83% and 93.65%, respectively. Their positive predictive values were 97.73% and 93.75%, respectively, and the negative predictive values were 53.04% and 42.45%, respectively. The consistency rates of the two rapid detection reagents with quantitative fluorescence PCR assay were 72.41% and 58.62%, respectively, and the kappa coefficient values were 0.48 and 0.27, respectively. The overall detection rate of reagent A and its detection rate for multiple epidemic cases were superior to those of reagent W. The mean Ct values of true positive samples detected by the two rapid detection reagents were (22.54±3.36) and (21.85±3.33), respectively, and the difference was not statistically significant. Conclusion Sensitivity is the key factor affecting the effectiveness of influenza viral antigen rapid detection reagent. The results of the two influenza viral antigen rapid detection reagents are significantly different from that of quantitative fluorescence PCR assay; and hence, they are not suitable for the diagnosis of influenza B cases in schools.
2023, Vol. 30 
