SARS-CoV-2 seroprevalence in the city of Puerto Madryn: Underdiagnosis and relevance of children in the pandemic

• Published in: PloS one Vol. 17; no. 3; p. e0263679
• Main Authors: Schonfeld, Daniel, Fernández, Hugo, Ramírez, Julio, Acosta, Denisse, Becerra, Julián, Wettstein, Magali, Strella, Teresa, Vaccaro, Marcelo, Arias, Sergio, Rodríguez Calvo, Vilma, Neme, Roberto, Pérez-Chada, Daniel
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 14-03-2022; Public Library of Science (PLoS)
• Subjects: Adolescent; Adult; Age; Age Distribution; Age groups; Aged; Analysis; Antibodies; Antibodies, Viral - blood; Argentina - epidemiology; Biology and life sciences; Care and treatment; Child; Child, Preschool; Children; Comorbidity; Confidence intervals; Consent; Coronaviruses; COVID-19; COVID-19 - blood; COVID-19 - epidemiology; Cross-Sectional Studies; Demographics; Demography; Diagnosis; Female; Health risks; Hospitals; Humans; Immunoenzyme technique; Immunoglobulin G; Immunoglobulin G - blood; In vitro methods and tests; Infant; Infant, Newborn; Infections; Informed consent; Male; Mathematical analysis; Medicine and Health Sciences; Middle Aged; Pandemics; People and Places; Population studies; Prevalence; Primary care; Respiratory diseases; Sample Size; SARS-CoV-2 - immunology; Seroepidemiologic Studies; Seroepidemiology; Serology; Severe acute respiratory syndrome; Severe acute respiratory syndrome coronavirus 2; Socioeconomics; Spike Glycoprotein, Coronavirus - immunology; Spike protein; Statistical analysis; Supervision; Viral diseases; Young Adult; Argentina
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0263679

Reported cases of COVID-19 may be underestimated due to mild or asymptomatic cases and a low testing rate in the general population.
What is the seroprevalence of SARS-CoV-2 infection in the general population and how it compares with the data on SARS-CoV-2 cases reported by a national health surveillance system (SNVS 2.0).
This was a population-based, seroepidemiological, cross-sectional study in the city of Puerto Madryn, a middle size city in the Province of Chubut, Argentina. The study period was between March 3 and April 17, 2021. The sample size was calculated using the technique of calculation of confidence intervals for a proportion. Participants were selected using stratified and cluster probability sampling. A total of 1405 subjects were invited to participate in the study. Participants were divided into the following four age groups: 1) 0 to 14, 2) 15 to 39, 3) 40 to 64, and 4) 65 or older. After informed consent was obtained, a blood sample was taken by puncture of the fingertip, and a structured questionnaire was administered to evaluate demographics, socioeconomic status, level of education, comorbidities and symptoms suggestive of COVID-19. COVID-19 seroprevalence was documented using an immunoenzymatic test for the in vitro detection of IgG antibodies specific to the spike protein of SARS-CoV-2.
A total of 987 participants completed the survey. Seropositivity in the full study population was 39,2% and in those under 15 years of age, 47.1%. Cases reported by the SNSV 2.0 amounted to 9.35% of the total population and 1.4% of those under 15 years of age.
The prevalence of COVID-19 infection in the general population is four times higher than the number of cases reported by the SNVS 2.0 in the city of Puerto Madryn. For each child under the age of 15 identified by the SNVS 2.0 with COVID-19, there are more than 30 unrecognized infections. Seroepidemiological studies are important to define the real extent of SARS-CoV-2 infection in a particular community. Children may play a significant role in the progression of the current pandemic.