Upper respiratory tract SARS-CoV-2 RNA loads in symptomatic and asymptomatic children and adults

• DOI: 10.1016/j.cmi.2021.08.001
• Publication Date: 2021-08-09T05:41:08Z
• Authors: Rosa Costa; Felipe Bueno; Eliseo Albert; Ignacio Torres; Silvia Carbonell-...; Ana Barrés-Fernández; David Sánchez; Carmelo Padrón; Javier Colomina; María Isabel Láza...; José Rafael Bretó...; Cecilia Martínez-...; David Navarro
• Keywords: Adult; SARS-CoV-2; COVID-19; Viral Load; SARS-CoV-2 RNA; 3. Good health; 03 medical and health sciences; 0302 clinical medicine; Nasopharynx; Adults; Humans; RNA, Viral; Viral load; Original Article; Child; Children; Asymptomatic Infections; Upper respiratory tract; Retrospective Studies

ABSTRACTObjectivesThere is limited information comparing SARS-CoV-2 RNA load in the upper respiratory tract (URT) between children and adults, either presenting with COVID-19 or asymptomatic. Here we conducted a retrospective, single center study involving a large cohort of SARS-CoV-2 infected individuals to address this issue.Patients and MethodsA total of 1,184 consecutive subjects (256 children and 928 adults) testing positive for SARS-COV-2 RNA in nasopharyngeal exudates (NP) were included, of whom 424 (121 children and 303 adults) had COVID-19 not requiring hospitalization and 760 (135 children and 625 adults) were asymptomatic close contacts of COVID-19 patients. SARS-CoV-2 RNA testing was carried out using the TaqPath COVID-19 Combo Kit (Thermo Fisher Scientific, MS, USA). The AMPLIRUN® TOTAL SARS-CoV-2 RNA Control (Vircell SA, Granada, Spain) was used for estimating SARS-CoV-2 RNA loads (in copies/mL).ResultsMedian SARS-COV-2 RNA loads were comparable between adults and children with COVID-19 (7.14 log10 copies/ml vs. 6.98 log10 copies/ml; P=0.094). Median SARS-CoV-2 RNA load in asymptomatic children and adults was similar (6.20 log10 copies/ml vs. 6.48 log10 copies/ml; P=0.97). Children with COVID-19 symptoms displayed SARS-CoV-2 RNA loads comparable to their asymptomatic counterparts (P=0.61). Meanwhile in adults, median SARS-CoV-2 RNA load was significantly higher in symptomatic than in asymptomatic subjects (P=<0.001), yet comparable (P=0.61) when the analysis excluded patients sampled within 48 h after symptoms onset.ConclusionsThe data suggest that children may be drivers of SARS-CoV-2 transmission in the general population at the same level as adults.