학술논문
Saliva molecular testing bypassing RNA extraction is suitable for monitoring and diagnosing SARS-CoV-2 infection in children
Document Type
article
Author
Marta Alenquer; Tiago Milheiro Silva; Onome Akpogheneta; Filipe Ferreira; Sílvia Vale-Costa; Mónica Medina-Lopes; Frederico Batista; Ana Margarida Garcia; Vasco M. Barreto; Cathy Paulino; João Costa; João Sobral; Maria Diniz-da-Costa; Susana Ladeiro; Rita Corte-Real; José Delgado Alves; Ricardo B. Leite; Jocelyne Demengeot; Maria João Rocha Brito; Maria João Amorim
Source
PLoS ONE, Vol 17, Iss 6 (2022)
Subject
Language
English
ISSN
1932-6203
Abstract
Background Adults are being vaccinated against SARS-CoV-2 worldwide, but the longitudinal protection of these vaccines is uncertain, given the ongoing appearance of SARS-CoV-2 variants. Children remain largely unvaccinated and are susceptible to infection, with studies reporting that they actively transmit the virus even when asymptomatic, thus affecting the community. Methods We investigated if saliva is an effective sample for detecting SARS-CoV-2 RNA and antibodies in children, and associated viral RNA levels to infectivity. For that, we used a saliva-based SARS-CoV-2 RT-qPCR test, preceded or not by RNA extraction, in 85 children aged 10 years and under, admitted to the hospital regardless of COVID-19 symptomatology. Amongst these, 29 (63.0%) presented at least one COVID-19 symptom, 46 (54.1%) were positive for SARS-CoV-2 infection, 28 (32.9%) were under the age of 1, and the mean (SD) age was 3.8 (3.4) years. Saliva samples were collected up to 48 h after a nasopharyngeal swab-RT-qPCR test. Results In children aged 10 years and under, the sensitivity, specificity, and accuracy of saliva-RT-qPCR tests compared to NP swab-RT-qPCR were, respectively, 84.8% (71.8%–92.4%), 100% (91.0%–100%), and 91.8% (84.0%–96.6%) with RNA extraction, and 81.8% (68.0%–90.5%), 100% (91.0%–100%), and 90.4% (82.1%–95.0%) without RNA extraction. Rescue of infectious particles from saliva was limited to CT values below 26. In addition, we found significant IgM positive responses to SARS-CoV-2 in children positive for SARS-CoV-2 by NP swab and negative by saliva compared to other groups, indicating late infection onset (>7–10 days). Conclusions Saliva is a suitable sample type for diagnosing children aged 10 years and under, including infants aged