Utility of the Presence of Anti-SARS-CoV-2 Antibodies in Detecting COVID-19 in Symptomatic Children and Adolescents: An Analytical Cross-sectional Study

Background: Understanding immunoreactivity against SARS-CoV-2 provides a basis for the pathophysiology of COVID-19 while also providing a means to confirm the disease and reduce its transmission. Methods: The present cross-sectional study was conducted from February 1^st, 2020 to December 30^th, 2022. The patients’ characteristics, clinical and laboratory data, Polymerase Chain Reaction (PCR) results, and the presence of anti-SARS-CoV-2 antibodies (serology testing) were recorded. Results: A total of 182 children were included. PCR returned positive in 60.4%, while serology indicated infection in 86.4% of the participants. Sex as a factor was not significantly associated with the results of either of the tests. However, seropositive children were older (p < 0.001), while PCR-positive children were younger (p < 0.01). Those who presented with cough (p < 0.05) or Multisystem Inflammatory Syndrome (MIS-C) (p < 0.05) had higher seropositivity rates than those without. In contrast, those who presented with fever (p < 0.001) or seizures (p < 0.01) had higher chances of having a positive PCR for COVID-19. In individuals suffering from arthralgia, limping, or arthritis, positive serology was observed in 96.3%, 95.2%, and 96.9%, respectively. However, positive results from PCR were observed in 67.2%, 67.1%, and 30.3% of the mentioned individuals, respectively. Conclusion: Anti-SARS-CoV-2 serology is a valuable diagnostic tool in individuals presenting late with arthralgia, arthritis, limping, MIS-C, or other delayed presentations, especially when PCR returns negative for the virus.