Diagnostic accuracy of direct reverse transcription-polymerase chain reaction using guanidine-based and guanidine-free inactivators for SARS-CoV-2 detection in saliva samples

This study aimed to evaluate diagnostic accuracy of SARS-CoV-2 RNA detection in saliva samples treated with a guanidine-based or guanidine-free inactivator, using nasopharyngeal swab samples (NPS) as referents. Based on the NPS reverse transcription-polymerase chain reaction (RT-PCR) results, participants were classified as with or without COVID-19. Fifty sets of samples comprising NPS, self-collected raw saliva, and saliva with a guanidine-based, and guanidine-free inactivator were collected from each group. In patients with COVID-19, the sensitivity of direct RT-PCR using raw saliva and saliva treated with a guanidine-based and guanidine-free inactivator was 100.0%, 65.9%, and 82.9%, respectively, with corresponding concordance rates of 94.3% (κ=88.5), 82.8% (κ=64.8), and 92.0% (κ=83.7). Among patients with a PCR Ct value of <30 in the NPS sample, the positive predictive value for the three samples was 100.0%, 80.0%, and 96.0%, respectively. The sensitivity of SARS-CoV-2 RNA detection was lower in inactivated saliva than in raw saliva and lower in samples treated with a guanidine-based than with a guanidine-free inactivator. However, in individuals contributing to infection spread, inactivated saliva showed adequate accuracy regardless of the inactivator used. Inactivators can be added to saliva samples collected for RT-PCR to reduce viral transmission risk while maintaining adequate diagnostic accuracy.PMID:38452822 | DOI:10.1016/j.jviromet.2024.114909

Source: Journal of Virological Methods - March 7, 2024 Category: Virology Authors: Takashi Katsuno Moto Kimura Junko Terada-Hirashima Yukumasa Kazuyama Masato Ikeda Ataru Moriya Masami Kurokawa Ayano Motohashi Erina Isaka Momoko Morishita Kazuki Kawajiri Kazuo Hakkaku Susumu Saito Yuriko Terayama Yuriko Sugiura Yoh Yamaguchi Hiroshi Tak Source Type: research