The impact of viral load in influenza-like illness on the isolation efficiency of influenza viruses
Objective To analyze the effect of viral load in influenza-like illness on the isolation efficiency of influenza viruses,and improve the quality and efficiency of influenza virus isolation work.Methods From Jan.to Oct.2023,320 nucleic acid-positive influenza-like illness specimens were collected from the district sentinel hospitals and surrounding districts and counties,inoculated into Mardin-Darby canine kidney cells using adsorption and direct inoculation methods to compare the efficiency of influenza virus isolation.The specimens were then divided into three groups based on the threshold cycle in reverse transcription-quantitative polymerase chain reaction(RT-qPCR)for comparison,and relevant factors were analyzed.Results There was no significant difference in the effect of gender on the results of influenza virus isolation(direct inoculation:x2=0.676,P＞0.05;adsorption:x2=1.359,P＞0.05).The number of influenza virus strains isolated by direct inoculation method was significantly higher than that by adsorption method,the difference was statistically significant(x2=20.516,P＜0.05).The lower the CT value,the higher the positive rate of influenza virus isolation.The differences in the separated positive rates for different Ct values was statistically significant(direct inoculation:x2=35.594,P＜0.05;adsorption:x2=15.496,P＜0.05).Among the different inoculation methods,there was no significant difference in influenza virus positive rate isolated from Influenza A subtype H3N2 and H1N1(direct inoculation:x2=1.563,P＞0.05;adsorption:x2=1.214,P＞0.05).Conclusion In influenza virus cell isolation experiments,using the direct inoculation method and selecting specimens with high influenza virus load(Ct value＜30)could effectively increase the positive rate of influenza virus isolation.
万方数据
维普
