Abstract:

Objective To investigate the clinical application value of nucleic acid point-of-care testing （POCT） and colloidal gold immunoassay（antigen assay）for influenza A virus （FluA）. Methods Nasal swab samples from 56 patients with suspected influenza A with fever and cough in East Hospital of Tongji University（South Branch） from February 20，2023 to April 5，2023 were collected. FluA was determined by colloidal gold immunoassay，nucleic acid POCT and polymerase chain reaction（PCR）-fluorescent probe assay（fluorescent PCR），and the determination efficiency of colloidal gold immunoassay and nucleic acid POCT was compared with fluorescent PCR as standard. The clinical data of FluA determined by colloidal gold immunoassay and nucleic acid POCT were analyzed retrospectively. Results Among the 56 samples，the positive rates of colloidal gold immunoassay，fluorescent PCR and nucleic acid POCT were 32.14%，60.71% and 62.50%，respectively. The determination rate of FluA by colloidal gold immunoassay was lower than that by fluorescent PCR（P<0.05），and nucleic acid POCT had good consistency with fluorescent PCR（Kappa=0.962，P>0.05）. The turn-around time（TAT） of colloidal gold immunoassay and nucleic acid POCT was <60 min，and the TAT of fluorescent PCR was 240 min. From February 20，2023 to April 5，2023，a total of 12 107 nasal swab samples were determined by colloidal gold immunoassay with a positive rate of 34.92%. Totally，7 924 clinical samples were determined by nucleic acid POCT with a positive rate of 71.02%. The positive rate of nucleic acid POCT for FluA was higher than that of colloidal gold immunoassay of the same age group. Conclusions The sensitivity of nucleic acid POCT is higher than that of colloidal gold immunoassay. Nucleic acid POCT could be used as a rapid determination method for FluA，which is worthy of further promotion and usage in clinical practice.

Key words: Influenza A virus, Respiratory tract infection, Antigen, Nucleic acid, Point-of-care testing