Saliva‐based Proteinase K method: A rapid and reliable diagnostic tool for the detection of SARS‐COV‐2 in children

Early and accurate detection of viruses in children might help prevent transmission and severe diseases. In this study, the severe acute respiratory syndrome coronavirus 2 (SARS‐COV‐2) detection in children was evaluated using saliva specimens with a Proteinase K (PTK)‐based RNA preparation, as saliva collection is a simple and noninvasive procedure, even in young children, with fewer concerns about sample contamination. The saliva‐based PTK and the conventional paired nasopharyngeal aspiration (NPA)‐based detection methods were compared between COVID‐19‐positive and ‐negative children. In addition, the detection rate for SARS‐COV‐2 and the difference between admission and discharge by the saliva‐based PTK method was tested in COVID‐19 patients. The diagnostic accuracy of the saliva‐based PTK method was 98.8% compared to NP swab‐based reverse transcriptase polymerase chain reaction. Saliva samples showed high sensitivity (94.1%) and specificity (100%) when using the PTK method. Furthermore, the saliva‐based PTK method significantly reduced the test processing time by 2 h. Notably, Ct values at discharge increased in saliva samples compared with those at admission, which might indicate patients' clinical conditions or virus activity. In conclusion, the saliva‐based PTK implemented in this study streamlines RNA extraction, making the process faster, safer, and more cost‐effective, demonstrating that this method is a rapid and reliable diagnostic tool for SARS‐CoV‐2 detection in children.