PD189 - IN CHILDREN YOUNGER THAN 3 YEARS OLD, RT-PCR IN ORAL SWABS IS BETTER THAN ANTIGEN RAPID TEST FOR DETECTION OF SARS-COV-2 INFECTION? (ID 969)
- Cinta Moraleda (Spain)
- Sara Domínguez (Spain)
- Juan Miguel Mesa (Spain)
- Paula García (Spain)
- María De la Serna (Spain)
- Jose A. Alonso-Cadenas (Spain)
- Amanda Bermejo (Spain)
- Gema Sabrido (Spain)
- Leticia Martinez-Campos (Spain)
- Aranzazu Flavia González-Posada (Spain)
- Marta Illán-Ramos (Spain)
- Jorge Lorente (Spain)
- Ana Belen Jimenez (Spain)
- Álvaro Ballesteros (Spain)
- David Aguilera-Alonso (Spain)
- Daniel Blázquez-Gamero (Spain)
- Alfredo Tagarro (Spain)
- Working group EPICO-AEP (Spain)
Abstract
Backgrounds:
RT-PCR using nasopharyngeal swabs (NPS) is the gold standard for the SARS-CoV-2 infection diagnosis. Antigen rapid diagnostic tests (Ag-RDT) have replaced RT-PCR on NPS in several situations due to their low cost and convenience. RT-PCR in oral swabs is a more comfortable alternative than NPS. There is scarce information on the accuracy of both techniques in children younger than 3 years old.
Methods
We present a secondary analysis of a cross-sectional multicenter study that evaluated the adequacy of Ag-RDT on NPS and oral swab RT-PCR compared to the gold standard in children. We offered participation to children 0-18 years old with COVID-19 symptoms of ≤5 days of duration, whose parents consented between February and March 2021. Two NPS (Ag-RDT and RT-PCR) and one oral swab for RT-PCR were collected at emergency departments, in ten Spanish hospitals. A subanalysis of the children younger than 3 years old was performed.
Results:
1174 children were included in the main analysis. The median age was 3.8 years (interquartile range (IQR), 1.7-9.0), 516/1174 (44.0%) were ≤3 years old. A total of 18/516 (3.5%) children ≤3 years old tested positive by at least one of the techniques. The performance of the two analyzed tests versus the gold standard is shown in table 1. Oral swab RT-PCR showed similar performance in children stratified by age. By contrast, Ag-RDT showed lower sensitivity in children ≤3 years (Table 1). Among the four cases with negative Ag-RDT and positive oral swab, 3 were ≤3 years old.
Conclusions/Learning Points:
RT-PCR on oral swabs is an accurate option for SARS-CoV-2 testing in children ≤3 years old, but Ag-RDT has poor sensitivity. Younger children might benefit from oral swab RT-PCR in testing guidelines, possibly even before Ag-RDT.
