key: cord-0792722-tnmyap0h
authors: Bahar, B.; Simpson, J. N.; Biddle, C.; Campbell, A.; Dome, J. S.; DeBiasi, R. L.; Mowbray, C.; Marguilies, S.; Sherman, A.; Reuben, J.; Delaney, M.
title: Estimated SARS-CoV-2 Seroprevalence in Healthy Children and Those with Chronic Illnesses in The Washington Metropolitan Area as of October 2020
date: 2021-02-01
journal: nan
DOI: 10.1101/2021.01.30.21250830
sha: 1db730c5a2fb6206c1d9c46e14f8846ad85aaa1e
doc_id: 792722
cord_uid: tnmyap0h

The estimated SARS-CoV-2 seroprevalence in children was found to be 9.46% for the Washington Metropolitan area. Hispanic/Latinx individuals were found to have higher odds of seropositivity. While chronic medical conditions were not associated with having antibodies, previous fever and body aches were predictive symptoms.

Children's National Hospital (CNH) observed its first pediatric case of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in mid-March 2020. 1 Since then, Coronavirus disease 2019 (COVID-19) has been spreading broadly in the region. 2 As of mid-January 2021, our institution had performed more than 50,700 SARS-CoV-2 reverse transcriptase-polymerase chain reaction (RT-PCR) tests for the pediatric community. The monthly percent positivity ranged between 2.84% to 11.10% with an average 6.1% viral positive rate. We

From July to October 2020, a total of 385 individuals between 2 months and 22 years old participated, and 38 individuals were found to have antibodies against SARS-CoV-2 (Table 1) . After adjustment for test accuracy, the estimated SARS-CoV-2 seroprevalence in the Washington Metropolitan area was found to be 9.46 (95% CI 6.68-13.00) cases per 100 children at risk.

Age, sex, number of household members, multiple participation from the same family, Medicaid membership, median household income based on reported zip code and state of residency were not found to be associated with having antibodies (p > 0.05 [all]); however, both Hispanic/Latinx race and ethnicity were found to be predictors of seropositivity compared to White race ( . CC-BY-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review)

The copyright holder for this preprint this version posted February 1, 2021. ;  Most of the participants (251/385) reported no previous symptoms. Of the individuals who tested positive for anti-SARS-CoV-2 antibody, the most commonly reported symptoms experienced since March 1, 2020 were fever (31.6%), headache (28.9%) and cough (26.3%). After adjustment for age and sex, bivariate logistic regression showed that total number of symptoms 

The seroprevalence of SARS-CoV-2 among the pediatric population estimated in our analysis of 9.46% was higher than previous studies that included immunocompromised participants or healthy children. 5, 6 Furthermore, there was no difference in the odds of being seropositive between chronic illness groups, which is particularly notable since immunocompromised children accounted for a large portion of our sample. Given our approach, which included both healthy and individuals with chronic illnesses, and accounted for test accuracy, we believe our estimate is a close approximation of seroprevalence for the diverse pediatric population in our region.

A systematic review of 18 studies on COVID-19 symptomatology in children reported fever and cough to be the most common COVID-19-related symptoms, other symptoms to be present in less than 10-20% of patients in the reported studies, and asymptomatic individuals to range from 14.6% to 42% in this age group. 7 These findings are similar to our observations. Furthermore, parallel to our previous report of higher rates of SARS-CoV-2 infection in minority children 8 , Hispanic/Latinx children had a higher seropositivity rate compared to whites which was previously reported for adults for the Baltimore-Washington, DC region. 9 We also observed antibody loss/non-presence in participants with mild symptomatology which is a known phenomenon for COVID-19. 10 The present work has some limitations. DC Health and CNH sites used similar, but not identical questionnaire instruments. Statistical models were not adjusted for correlated antibody results from the same household; however, this situation only counted for 10.4% (n=40) of the participants and most likely had a negligible effect on the seroprevalence estimation. Further, our sampling approach resulted in the inclusion of more chronically ill children than healthy . CC-BY-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted February 1, 2021. children, which may introduce selection and reporting biases. Despite these limitations, the current analysis has several strengths. The pediatric sample achieved demonstrated great demographic diversity, and participants enrolled at CNH sites provided consent to be contacted in the future for repeated testing, enabling follow up studies to be carried out. Most notably, children with underlying medical illnesses have not been studied in this way, and as a result, we feel our findings offer important information as all children, whether living with chronic illness or not, must be considered for "back to school" transitions.

Although we report a higher seroprevalence than other studies, our observed 9.46% seroprevalence rate remains well below the levels at which herd immunity has been estimated to occur 11 , however, per CDC's reports, there is an increased seropositivity rate trend for most of the US states 12 . Future studies should focus on longitudinal seropositivity assessments among children to determine the impact of continued infections in the community, vaccine implementation, and returning to school and extracurricular programs for much needed social, emotional and behavioral development. OR: Odds Ratio. CI: Confidence Interval. *Adjusted for age and sex. Numbers may not sum to total due to missing data and percentages may not sum to 100% due to rounding.

. CC-BY-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review)

The copyright holder for this preprint this version posted February 1, 2021. ; https://doi.org/10.1101/2021.01.30.21250830 doi: medRxiv preprint

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