ABSTRACT
Objectives: The extent of SARS-CoV-2 infection amongst children and their role in transmission remains unclear. Therefore, we aimed to estimate the SARS-CoV-2 antibody seroprevalence amongst children who presented to our hospital for non-COVID-19-related morbidity during the first and second epidemic wave in 2020 and compared these to the general Dutch paediatric population. Methods: We collected residual plasma samples from all paediatric patients (1 month-17 years of age) visiting our clinic or emergency room, who had blood drawing for various medical reasons. Samples were analysed for the presence of total antibodies against SARS-CoV-2 by Wantai ELISA. The seroprevalence in two separate periods (July-Sep 2020, and Oct-Dec 2020) was compared to regional and national data (PIENTER-Corona study, September 2020), and associations with co-morbidities were assessed. Results: A total of 209 samples in period 1 and 240 samples in period 2 were collected (median age 7.1 years, IQR 1.5-13.5). SARS-CoV-2 antibodies were detected in 4.1% and 13.8%, respectively (p< 0.001). Seroprevalence was higher compared to national paediatric data, but did not differ with regional estimates. Most children with SARS-CoV-2 antibodies were seen in the outpatient clinic for general paediatric problems with no differences in medical reasons for presentation between the two periods. Conclusions: These data confirm a rapid three-fold increase in SARS-CoV-2 seroprevalence in paediatric patients in the second half of 2020 with a trend towards a higher seroprevalence compared to randomly-selected children in a nationwide study. Underlying morbidity in children might not play an important role in acquiring SARS-CoV-2 infection.
ABSTRACT
OBJECTIVES: To assess the diagnostic performance of rapid lateral flow immunochromatographic assays (LFAs) compared with an ELISA and nucleic acid amplification tests (NATs) in individuals with suspected coronavirus disease 2019 (COVID-19). METHODS: Patients presenting to a Dutch teaching hospital were eligible between 17 March and 10 April 2020, when they had respiratory symptoms that were suspected for COVID-19. The performances of six different LFAs were evaluated in plasma samples obtained on corresponding respiratory sample dates of NATs testing. Subsequently, the best performing LFA was evaluated in 228 patients and in 50 sera of a historical patient control group. RESULTS: In the pilot analysis, sensitivity characteristics of LFA were heterogeneous, ranging from 2/20 (10%; 95% CI 0%-23%) to 11/20 (55%; 95% CI 33%-77%). In the total cohort, Orient Gene Biotech COVID-19 IgG/IgM Rapid Test LFA had a sensitivity of 43/99 (43%; 95% CI 34%-53%) and specificity of 126/129 (98%; 95% CI 95%-100%). Sensitivity increased to 31/52 (60%; 95% CI 46%-73%) in patients with at least 7 days of symptoms, and to 21/33 (64%; 95% CI 47%-80%) in patients with C-reactive protein (CRP) ≥100 mg/L. Sensitivity and specificity of Wantai SARS-CoV-2 Ab ELISA was 59/95 (62%; 95% CI 52%-72%) and 125/128 (98%; 95% CI 95%-100%) in all patients, respectively, but sensitivity increased to 38/48 (79%; 95% CI 68%-91%) in patients with at least 7 days of symptoms. CONCLUSIONS: There is large variability in diagnostic test performance between rapid LFAs, but overall limited sensitivity and high specificity in acutely admitted patients. Sensitivity improved in patients with longer existing symptoms or high CRP. LFAs should only be considered as additional triage tools when these may lead to the improvement of hospital logistics.