Background
The closure of educational institutions was one of the containment strategies for COVID-19, assuming that children had a high probability of acquiring asymptomatic or very mild SARS-CoV-2 infections and transmitting it to their most vulnerable environment. Paraguay proposed the gradual and voluntary return to classes in a blended system based on the immunization of teachers. Community transmission of COVID-19 in Asunción and Central in November was at level 3 (WHO scale), with circulation of the DELTA variant. The objective was to estimate the anti-SARS-CoV-2 seroprevalence among the school population.
Methods
Cross-sectional study, from October 25 to November 5, 2021. Structured surveys were applied to basic school students (kindergarten to ninth grade) from four educational institutions in Asunción and the Central department. Fingerstick blood samples for antibody detection by rapid immunochromatographic test (Zhejiang Orient Gene Biotech Co., Ltd.). Frequencies, percentages, mean and standard deviation (SD) were calculated.
Results
The population was 778 schoolchildren from kindergarten to ninth grade; Fifty two percent (404/778) were female, mean age 10 years (SD ±3); Two percent (19/778) reported comorbidity, Nine percent (21/245) reported a previous episode of the disease with mild symptoms (runny nose, cough). The overall seroprevalence was 31% (245/778), with 98% (240/245) being positive for IgG antibodies.
Conclusion
The overall seroprevalence was high and most infections were asymptomatic. Immunization was recommended in the school population considering the level of community transmission and the circulation of a variant of concern.