Low performance of a SARS-CoV-2 point-of-care lateral flow immunoassay in symptomatic children during the pandemic()

Scotta, Marcelo Comerlato; de David, Caroline Nespolo; Varela, Fernanda Hammes; Sartor, Ivaine Tais Sauthier; Polese-Bonatto, Márcia; Fernandes, Ingrid Rodrigues; Zavaglia, Gabriela Oliveira; Ferreira, Charles Francisco; Kern, Luciane Beatriz; Santos, Amanda Paz; Krauzer, João Ronaldo Mafalda; Pitrez, Paulo Márcio; de Almeida, Walquiria Aparecida Ferreira; Porto, Victor Bertollo Gomes; Stein, Renato T.

OBJECTIVE: To evaluate the accuracy of an antibody point-of-care lateral flow immunoassay (LFI - Wondfo Biotech Co., Guangzhou, China) in a pediatric population. METHODS: Children and adolescents (2 months to 18 years) with signs and symptoms suggestive of acute SARS-CoV-2 infection were prospectively investigated with nasopharyngeal RT-PCR and LFI at the emergency room. RT-PCR was performed at baseline, and LFI at the same time or scheduled for those with less than 7 days of the clinical picture. Overall accuracy, sensitivity and specificity were assessed, as well as according to the onset of symptoms (7-13 or ≥14 days) at the time of LFI test. RESULTS: In 175 children included, RT-PCR and LFI were positive in 51 (29.14%) and 36 (20.57%), respectively. The overall sensitivity, specificity, positive and negative predictive value was of 70.6% (95%CI 56.2-82.5), 96.8% (95%CI 91.9-99.1), 90.0% (95%CI 77.2-96.0), and 88.9% (95%CI 83.9-92.5), respectively. At 7-13 and ≥14 days after the onset of symptoms, sensitivity was 60.0% (95%CI 26.2-87.8) and 73.2% (95%CI 57.1-85.8) and specificity was 97.9% (95%CI 88.7-99.9) and 96.1% (95%CI 89.0-99.2), respectively. CONCLUSION: Despite its high specificity, in the present study, the sensitivity of LFI in children was lower (around 70%) than most reports in adults. In acute care settings, although a positive result is informative, a negative LFI test cannot rule out COVID-19 in children.