Estimated SARS-CoV-2 Seroprevalence Among Persons Aged <18 Years - Mississippi, May-September 2020

Combination of rRT-PCR and Clinical Features to Predict Coronavirus Disease 2019 for Nosocomial Infection Control

Background

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), immediately became a pandemic. Therefore, nosocomial infection control is necessary to screen for patients with possible COVID-19.

Objective

This study aimed to investigate commonly measured clinical variables to predict COVID-19.

Methods

This cross-sectional study enrolled 1087 patients in the isolation ward of a university hospital. Conferences were organized to differentiate COVID-19 from non-COVID-19 cases, and multiple nucleic acid tests were mandatory when COVID-19 could not be excluded. Multivariate logistic regression models were employed to determine the clinical factors associated with COVID-19 at the time of hospitalization.

Results

Overall, 352 (32.4%) patients were diagnosed with COVID-19. The majority of the non-COVID-19 cases were predominantly caused by bacterial infections. Multivariate analysis indicated that COVID-19 was significantly associated with age, sex, body mass index, lactate dehydrogenase, C-reactive protein, and malignancy.

Conclusion

Some clinical factors are useful to predict patients with COVID-19 among those with symptoms similar to COVID-19. This study suggests that at least two real-time reverse-transcription polymerase chain reactions of SARS-CoV-2 are recommended to exclude COVID-19.

Pediatric diabetes mellitus hospitalizations and COVID-19 pandemic response measures

AIMS

In the United States, evidence suggests that during the COVID-19 pandemic, admissions of patients with diabetes mellitus (DM) have increased. This study assessed hospital admission rates for pediatric type 1 (T1DM) and type 2 (T2DM) diabetes mellitus during 2019-2021, and the potential influence of the timing of various pandemic response measures.

METHODS

Retrospective chart reviews were conducted of 854 T1DM and 135 T2DM hospital admissions between January 2019 and December 2021 in patients < 20 years old to collect demographic data, admission type, body mass index (BMI), and area deprivation index (ADI, a measure of socioeconomic vulnerability). Patients were divided into three cohorts based on their admission year: 2019 (Pre-pandemic), 2020 (Pandemic, Pre-vaccine), and 2021 (Pandemic, Post-vaccine). Admissions were categorized within each cohort by diagnosis (T1DM or T2DM) and clinical presentation (new onset, diabetic ketoacidosis: DKA). Cohorts were compared using an independent samples t-test for continuous variables or a chi-square test for categorical variables.

RESULTS

The incidence of T2DM hospitalizations tripled during the pandemic, increasing from 18 in 2019 (Pre-pandemic), to 55 in 2020 (Pandemic, Pre-vaccine), and 62 in 2021 (Pandemic, Post-vaccine). The rate of patients presenting with DKA was 15.4 % (95 % CI: 4 %-26.9 %) higher in 2020 (Pandemic, Pre-vaccine) among patients with new-onset T1DM (72/139 vs. 52/143), and 22.5 % (95 % CI: 9.6 %-35.4 %) higher in 2020 (Pandemic, Pre-vaccine) among T2DM patients (9/40 vs. 0/14). This increased rate of new onset T2DM significantly correlated with younger age (P = 0.046) and higher ADI score (P = 0.017), but not with BMI.

CONCLUSION

The incidence of T1DM hospitalizations did not increase during the pandemic; however, they tripled for T2DM patients. All new onset DM pediatric patients during the pandemic were more likely to present in DKA. Patients admitted with new onset T2DM were socioeconomically more vulnerable. For T1DM, the peak of local pediatric diabetes admissions in 2020 occurred slightly later coinciding with the reopening of primary care physicians (PCP) offices and schools.

Hybrid Learning Modality Did Not Reduce the Risk of COVID-19 Among Colorado Students

During the 2020-2021 school year, many schools adopted remote learning or a part-time in-person learning ("hybrid") approach to reduce the risk of in-school transmission of COVID-19. The purpose of this work is to describe case rates of COVID-19 in schools practicing different learning modalities on rates of COVID-19 to support risk-benefit decisions in the context of respiratory disease outbreaks. We conducted a person-time-at-risk analysis of rates of COVID-19, as well as testing and test positivity rates among Colorado students. Schools practicing remote learning had a lower adjusted rate of COVID-19 cases compared to either hybrid or in-person learning modalities. Students attending a school with remote learning had fewer reported tests, and test positivity was higher for remote learning. Our analysis found that both case rate and test positivity were similar in hybrid and in-person learning modalities, indicating that hybrid learning modalities may not reduce the risk of respiratory disease transmission.

Seroepidemiological and Molecular Survey for the Detection of SARS-CoV-2 Infection among Children in Iran, September 2020 to June 2021: 1-Year Cross-Sectional Study

A population-based seroepidemiological and molecular survey on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was performed to detect induced antibodies to prior exposure and active infection of children aged 14 years or less in Tehran between 19 September 2020 and 21 June 2021. Moreover, correlations between the children's demographic data and coronavirus disease 2019 (COVID-19) symptoms with the infection status were investigated. Out of 1517 participants, cardinal symptoms of COVID-19 (fever > 38 °C and/or cough and/or diarrhea) were detected in 18%, and serological history of SARS-CoV-2 infection and polymerase chain reaction (PCR) positivity were confirmed in 33.2% and 10.7% of the weighted population, respectively. The prevalence of SARS-CoV-2 infection was significantly higher among 10-14-year-old children. Active infection was significantly higher in symptomatic children and during autumn 2020 and spring 2021. The quantitative reverse transcription real-time PCR (RT-qPCR) positivity was significantly higher among families with a lower socioeconomic status, whereas no association between RT-qPCR or seropositivity was determined with household size, underlying diseases, or gender. In conclusion, high SARS-CoV-2 infection prevalence and seroprevalence were detected in children in Tehran in different seasons. Infection prevalence was significantly higher in older children and in those with a positive history of close contact with infected cases and/or lower socioeconomic status.

SARS-CoV-2 Serostatus and COVID-19 Illness Characteristics by Variant Time Period in Non-Hospitalized Children and Adolescents

OBJECTIVE

To describe COVID-19 illness characteristics, risk factors, and SARS-CoV-2 serostatus by variant time period in a large community-based pediatric sample.

DESIGN

Data were collected prospectively over four timepoints between October 2020 and November 2022 from a population-based cohort ages 5 to 19 years old.

SETTING

State of Texas, USA.

PARTICIPANTS

Participants ages 5 to 19 years were recruited from large pediatric healthcare systems, Federally Qualified Healthcare Centers, urban and rural clinical practices, health insurance providers, and a social media campaign.

EXPOSURE

SARS-CoV-2 infection.

MAIN OUTCOME(S) AND MEASURE(S)

SARS-CoV-2 antibody status was assessed by the Roche Elecsys^® Anti-SARS-CoV-2 Immunoassay for detection of antibodies to the SARS-CoV-2 nucleocapsid protein (Roche N-test). Self-reported antigen or PCR COVID-19 test results and symptom status were also collected.

RESULTS

Over half (57.2%) of the sample (N = 3911) was antibody positive. Symptomatic infection increased over time from 47.09% during the pre-Delta variant time period, to 76.95% during Delta, to 84.73% during Omicron, and to 94.79% during the Omicron BA.2. Those who were not vaccinated were more likely (OR 1.71, 95% CI 1.47, 2.00) to be infected versus those fully vaccinated.

CONCLUSIONS

Results show an increase in symptomatic COVID-19 infection among non-hospitalized children with each progressive variant over the past two years. Findings here support the public health guidance that eligible children should remain up to date with COVID-19 vaccinations.

Characterisation of infection-induced SARS-CoV-2 seroprevalence amongst children and adolescents in North Carolina

Few prospective studies have documented the seropositivity among those children infected with severe acute respiratory syndrome coronavirus 2. From 2 April 2021 to 24 June 2021, we prospectively enrolled children between the ages of 2 and 17 years at three North Carolina healthcare systems. Participants received at least four at-home serological tests detecting the presence of antibodies against, but not differentiating between, the nucleocapsid or spike antigen. A total of 1,058 participants were enrolled in the study, completing 2,709 tests between 1 May 2021 and 31 October 2021. Using multilevel regression with poststratification techniques and considering our assay sensitivity and sensitivity, we estimated that the seroprevalence of infection-induced antibodies among unvaccinated children and adolescents aged 2-17 years in North Carolina increased from 15.2% (95% credible interval, CrI 9.0-22.0) in May 2021 to 54.1% (95% CrI 46.7-61.1) by October 2021, indicating an average infection-to-reported-case ratio of 5. A rapid rise in seropositivity was most pronounced in those unvaccinated children aged 12-17 years, based on our estimates. This study underlines the utility of serial, serological testing to inform a broader understanding of the regional immune landscape and spread of infection.

Geographically skewed recruitment and COVID-19 seroprevalence estimates: a cross-sectional serosurveillance study and mathematical modelling analysis

OBJECTIVES

Convenience sampling is an imperfect but important tool for seroprevalence studies. For COVID-19, local geographic variation in cases or vaccination can confound studies that rely on the geographically skewed recruitment inherent to convenience sampling. The objectives of this study were: (1) quantifying how geographically skewed recruitment influences SARS-CoV-2 seroprevalence estimates obtained via convenience sampling and (2) developing new methods that employ Global Positioning System (GPS)-derived foot traffic data to measure and minimise bias and uncertainty due to geographically skewed recruitment.

DESIGN

We used data from a local convenience-sampled seroprevalence study to map the geographic distribution of study participants' reported home locations and compared this to the geographic distribution of reported COVID-19 cases across the study catchment area. Using a numerical simulation, we quantified bias and uncertainty in SARS-CoV-2 seroprevalence estimates obtained using different geographically skewed recruitment scenarios. We employed GPS-derived foot traffic data to estimate the geographic distribution of participants for different recruitment locations and used this data to identify recruitment locations that minimise bias and uncertainty in resulting seroprevalence estimates.

RESULTS

The geographic distribution of participants in convenience-sampled seroprevalence surveys can be strongly skewed towards individuals living near the study recruitment location. Uncertainty in seroprevalence estimates increased when neighbourhoods with higher disease burden or larger populations were undersampled. Failure to account for undersampling or oversampling across neighbourhoods also resulted in biased seroprevalence estimates. GPS-derived foot traffic data correlated with the geographic distribution of serosurveillance study participants.

CONCLUSIONS

Local geographic variation in seropositivity is an important concern in SARS-CoV-2 serosurveillance studies that rely on geographically skewed recruitment strategies. Using GPS-derived foot traffic data to select recruitment sites and recording participants' home locations can improve study design and interpretation.

Comparative Performance of Serological (IgM/IgG) and Molecular Testing (RT-PCR) of COVID-19 in Three Private Universities in Cameroon during the Pandemic

BACKGROUND

COVID-19 remains a rapidly evolving and deadly pandemic worldwide. This necessitates the continuous assessment of existing diagnostic tools for a robust, up-to-date, and cost-effective pandemic response strategy. We sought to determine the infection rate (PCR-positivity) and degree of spread (IgM/IgG) of SARS-CoV-2 in three university settings in Cameroon Method: Study volunteers were recruited from November 2020 to July 2021 among COVID-19 non-vaccinated students in three Universities from two regions of Cameroon (West and Centre). Molecular testing was performed by RT-qPCR on nasopharyngeal swabs, and IgM/IgG antibodies in plasma were detected using the Abbott Panbio IgM/IgG rapid diagnostic test (RDT) at the Virology Laboratory of CREMER/IMPM/MINRESI. The molecular and serological profiles were compared, and p < 0.05 was considered statistically significant.

RESULTS

Amongst the 291 participants enrolled (mean age 22.59 ± 10.43 years), 19.59% (57/291) were symptomatic and 80.41% (234/291) were asymptomatic. The overall COVID-19 PCR-positivity rate was 21.31% (62/291), distributed as follows: 25.25% from UdM-Bangangte, 27.27% from ISSBA-Yaounde, and 5% from IUEs/INSAM-Yaounde. Women were more affected than men (28.76% [44/153] vs. 13.04% [18/138], p < 0.0007), and had higher seropositivity rates to IgM+/IgG+ (15.69% [24/153] vs. 7.25% [10/138], p < 0.01). Participants from Bangangté, the nomadic, and the "non-contact cases" primarily presented an active infection compared to those from Yaoundé (p= 0.05, p = 0.05, and p = 0.01, respectively). Overall IgG seropositivity (IgM-/IgG+ and IgM+/IgG+) was 24.4% (71/291). A proportion of 26.92% (7/26) presenting COVID-19 IgM+/IgG- had negative PCR vs. 73.08% (19/26) with positive PCR, p < 0.0001. Furthermore, 17.65% (6/34) with COVID-19 IgM+/IgG+ had a negative PCR as compared to 82.35% with a positive PCR (28/34), p < 0.0001. Lastly, 7.22% (14/194) with IgM-/IgG- had a positive PCR.

CONCLUSION

This study calls for a rapid preparedness and response strategy in higher institutes in the case of any future pathogen with pandemic or epidemic potential. The observed disparity between IgG/IgM and the viral profile supports prioritizing assays targeting the virus (nucleic acid or antigen) for diagnosis and antibody screening for sero-surveys.

Monitoring of Auditory Function in Newborns of Women Infected by SARS-CoV-2 during Pregnancy

BACKGROUND

Gestational SARS-CoV-2 infection can impact maternal and neonatal health. The virus has also been reported to cause newborn sensorineural hearing loss, but its consequences for the auditory system are not fully understood.

OBJECTIVE

The aim of this study was to evaluate the impact of maternal SARS-CoV-2 infection during pregnancy on newborn' hearing function during the first year of life.

METHODS

An observational study was conducted from 1 November 2020 to 30 November 2021 at University Modena Hospital. All newborns whose mother had been infected by SARS-CoV-2 during pregnancy were enrolled and underwent audiological evaluation at birth and at 1 year of age.

RESULTS

A total of 119 neonates were born from mothers infected by SARS-CoV-2 during pregnancy. At birth, five newborns (4.2%) presented an increased threshold of ABR (Auditory Brainstem Evoked Response), but the results were confirmed only in 1.6% of cases, when repeated 1 month later, while the ABR thresholds in all other children returned to normal limits. At the 1-year follow-up, no cases of moderate or severe hearing loss were observed, while concomitant disorders of the middle ear were frequently observed.

CONCLUSIONS

Maternal SARS-CoV-2 infection, regardless of the trimester in which it was contracted, appears not to induce moderate or severe hearing loss in infants. It is important to clarify the possible effect of the virus on late-onset hearing loss and future research is needed.

COVID-19 coronavirus infection in children: Clinical presentation, diagnosis, vaccination, and treatment

In late 2019, a new subtype of coronavirus named Severe Acute Respiratory Syndrome Coronavirus 2 (COVID-19 SARS-CoV-2) rapidly spread around the world, causing a global pandemic. Initially, the proportion of confirmed cases among children was relatively small, and it was believed that children were rarely infected. Subsequent observations have shown that in children and adolescents, the infection is either asymptomatic or paucisymptomatic, and therefore the true incidence is underestimated due to the lack of testing. The article systematizes the results of studies on the prevalence, diagnosis, clinical features, vaccination, and treatment of children with a new coronavirus infection COVID-19 SARS-CoV-2. The SARS-CoV-2 positivity rate throughout the peak of the pandemic in children was low compared to adults. Children are not only less likely to become infected with the virus, but they also endure the infection more easily than adults. The mortality rate in children with COVID-19 was <0.5%. In most children, infection is either asymptomatic or paucisymptomatic. Vaccination of children and adolescents is recommended mainly to achieve herd immunity in all age groups. However, there are no convincing data on the duration of the immune response, the level of the required protective antibody titer, as well as on the long-term side effects of vaccination due to the insufficient follow-up period and the uncertainty of the immune response criteria. As information is accumulated on the viral load of children and adolescents, their role in the transmission of the virus, diagnostic approaches in this age group are optimized. The effectiveness of the treatment was tested on patients admitted to the hospital, and recommendations for treatment were developed. Currently, global research efforts are focused on the protection of particularly vulnerable children, the prospects for total childhood vaccination, its effectiveness and safety.

Missing science: A scoping study of COVID-19 epidemiological data in the United States

Systematic approaches to epidemiologic data collection are critical for informing pandemic responses, providing information for the targeting and timing of mitigations, for judging the efficacy and efficiency of alternative response strategies, and for conducting real-world impact assessments. Here, we report on a scoping study to assess the completeness of epidemiological data available for COVID-19 pandemic management in the United States, enumerating authoritative US government estimates of parameters of infectious transmission, infection severity, and disease burden and characterizing the extent and scope of US public health affiliated epidemiological investigations published through November 2021. While we found authoritative estimates for most expected transmission and disease severity parameters, some were lacking, and others had significant uncertainties. Moreover, most transmission parameters were not validated domestically or re-assessed over the course of the pandemic. Publicly available disease surveillance measures did grow appreciably in scope and resolution over time; however, their resolution with regards to specific populations and exposure settings remained limited. We identified 283 published epidemiological reports authored by investigators affiliated with U.S. governmental public health entities. Most reported on descriptive studies. Published analytic studies did not appear to fully respond to knowledge gaps or to provide systematic evidence to support, evaluate or tailor community mitigation strategies. The existence of epidemiological data gaps 18 months after the declaration of the COVID-19 pandemic underscores the need for more timely standardization of data collection practices and for anticipatory research priorities and protocols for emerging infectious disease epidemics.

Feasibility of At-Home Virological and Serological Testing for SARS-CoV-2 in Children

Longitudinal virological and serological surveillance is essential for understanding SARS CoV-2 transmission among children but requires increased test capacity. We assessed the uptake of serial at-home testing in children (2-17 years) via mailed SARS-CoV-2 antibody and molecular tests. Completion rates demonstrated feasibility and sustainability of at-home testing across age groups.

Active Surveillance With Seroprevalence-based Infection Rates Indicates Racial Disparities With Pediatric SARS-CoV-2 Requiring Hospitalization in Mississippi, March 2020-February 2021

BACKGROUND

Racial disparities in SARS-CoV-2 infection, hospitalization, and multisystem inflammatory syndrome in children (MIS-C) have been reported. However, these reports have been based on incomplete data relying on passive reporting, unknown catchment populations, and unknown infection prevalence. We aimed to characterize population-based incidence of MIS-C and COVID-19 hospitalizations among non-Hispanic Black and White children using active surveillance based on seroprevalence-based cumulative incidence of pediatric SARS-CoV-2 infection in a defined catchment 16-county area of Mississippi.

METHODS

Active, population-based surveillance for MIS-C and acute COVID-19 hospitalizations meeting clinical and laboratory criteria was conducted by adjudicating clinicians at the major pediatric referral hospital for Mississippi, University of Mississippi Medical Center, from March 2020, to February 2021. Race-stratified SARS-CoV-2 seroprevalence was estimated using convenience samples from persons <18 years to calculate cumulative SARS-CoV-2 infections in the population.

RESULTS

Thirty-eight MIS-C cases and 74 pediatric acute COVID-19 hospitalizations were identified. Cumulative incidence of MIS-C was 4.7 times higher among Black compared with White children (40.7 versus 8.3 cases per 100,000 SARS-CoV-2 infections). Cumulative incidence of COVID-19 hospitalization was 62.3 among Black and 33.1 among White children per 100,000 SARS-CoV-2 infections.

CONCLUSIONS

From the same catchment area, active surveillance, and cumulative incidence of infection estimated by seroprevalence, we show strikingly higher incidence of SARS-CoV-2-hospitalization and MIS-C in non-Hispanic Black children compared with White children before COVID-19 vaccination introduction in children. These disparities in SARS-CoV-2 manifestations cannot be accounted for by differences in exposure or testing. Targeted vaccine interventions will lessen disparities observed with SARS-CoV-2 manifestations in children.

SARS-CoV-2 infections in infants in Haiti 2020–2021; evidence from a seroepidemiological cohort

Few data are available on frequency of SARS-CoV-2 infection among very young children in low- to middle-income countries (LMIC), with the studies that are available biased towards higher income countries with low reported infection and seroconversion rates. Between February 2019 and March 2021, 388 dried blood spot (DBS) samples were obtained from 257 children less than 30 months of age as part of a prospective observational cohort study of pregnant women and their infants in Haiti; longitudinal samples were available for 107 children. In a subsequent retrospective analysis, DBS samples were tested by ELISA for antibody targeting the receptor binding domain of the SARS-CoV-2 S1 protein. Over the course of the study, 16·7% of the infants became seropositive. All seropositive samples were collected after March 19, 2020 (the date of the first reported COVID-19 case in Haiti) with the highest hazards measured in August 2020. Sampling date was the only covariate associated with the hazard of seroconversion. Our data provide an estimate of SARS-CoV-2 infection rates among very young children without prior SARS-CoV-2 exposure during the initial pandemic waves in Haiti, and demonstrate that these children mount a detectable serological response which is independent of patient age.

Seroprevalence of SARS-CoV-2 among Children Visiting a Tertiary Hospital during the Prevaccination Period, Southwest Region, Saudi Arabia

Background: In the early days of the COVID-19 pandemic, tests to ascertain whether individuals were infected with SARS-CoV-2 were often unavailable. One method to deal with this issue is to test for SARS-CoV-2 antibodies. This study sought to determine the seroprevalence of SARS-CoV-2 in children in Saudi Arabia before vaccines were available to them. Methods: This study was conducted among children who visited the tertiary Maternity and Children Hospital in Abha city, Saudi Arabia. Serum samples were screened for SARS-CoV-2-specific IgG, IgM, and IgA antibodies using ELISA. The crude and adjusted seroprevalence values among the studied children were calculated. Results: Among the 413 children studied, the ages of enrolled patients ranged from newborn to 12 years, with a median age of three years. We identified 127 (30.7%) seropositive children. IgG was exclusively positive in 43 (10.4%); IgM was exclusively positive in 8 (1.9%), and IgA was exclusively positive in 15 (3.6%) children. Conclusions: This study is the first to estimate the seroprevalence of SARS-CoV-2 among the pediatric population seeking medical care in southwestern Saudi Arabia. The findings shed light on the dynamics of virus transmission in the community and provide a good reference for future studies. Future research should examine factors related to SARS-CoV-2 infection and seroprevalence among pediatric populations.

Clinical characteristics and risk factors for COVID-19 infection and disease severity: A nationwide observational study in Estonia

BACKGROUND

COVID-19 pandemic has led to overloading of health systems all over the world. For reliable risk stratification, knowledge on factors predisposing to SARS-CoV-2 infection and to severe COVID-19 disease course is needed for decision-making at the individual, provider, and government levels. Data to identify these factors should be easily obtainable.

METHODS AND FINDINGS

Retrospective cohort study of nationwide e-health databases in Estonia. We used longitudinal health records from 66,295 people tested positive for SARS-CoV-2 RNA from 26 February 2020 to 28 February 2021 and 254,958 randomly selected controls from the reference population with no known history of SARS-CoV-2 infection or clinical COVID-19 diagnosis (case to control ratio 1:4) to predict risk factors of infection and severe course of COVID-19. We analysed sociodemographic and health characteristics of study participants. The SARS-CoV-2 infection risk was slightly higher among women, and was higher among those with comorbid conditions or obesity. Dementia (RRR 3.77, 95%CI 3.30⎼4.31), renal disease (RRR 1.88, 95%CI 1.56⎼2.26), and cerebrovascular disease (RRR 1.81, 95%CI 1.64⎼2.00) increased the risk of infection. Of all SARS-CoV-2 infected people, 92% had a non-severe disease course, 4.8% severe disease (requiring hospitalisation), 1.7% critical disease (needing intensive care), and 1.5% died. Male sex, increasing age and comorbid burden contributed significantly to more severe COVID-19, and the strength of association for male sex increased with the increasing severity of COVID-19 outcome. The strongest contributors to critical illness (expressed as RRR with 95% CI) were renal disease (7.71, 4.71⎼12.62), the history of previous myocardial infarction (3.54, 2.49⎼5.02) and obesity (3.56, 2.82⎼4.49). The strongest contributors to a lethal outcome were renal disease (6.48, 3.74⎼11.23), cancer (3.81, 3.06⎼4.75), liver disease (3.51, 1.36⎼9.02) and cerebrovascular disease (3.00, 2.31⎼3.89).

CONCLUSIONS

We found divergent effect of age and gender on infection risk and severity of COVID-19. Age and gender did not contribute substantially to infection risk, but did so for the risk of severe disease Co-morbid health conditions, especially those affecting renin-angiotensin system, had an impact on both the risk of infection and severe disease course. Age and male sex had the most significant impact on the risk of severe COVID-19. Taking into account the role of ACE2 receptors in the pathogenesis of SARS-CoV-2 infection, as well as its modulating action on the renin-angiotensin system in cardiovascular and renal diseases, further research is needed to investigate the influence of hormonal status on ACE2 expression in different tissues, which may be the basis for the development of COVID-19 therapies.

Pediatric SARS-CoV-2 Seroprevalence in Arkansas Over the First Year of the COVID-19 Pandemic

BACKGROUND

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) seroprevalence studies largely focus on adults, but little is known about spread in children. We determined SARS-CoV-2 seroprevalence in children and adolescents from Arkansas over the first year of the coronavirus disease of 2019 (COVID-19) pandemic.

METHODS

We tested remnant serum samples from children ages 1-18 years who visited Arkansas hospitals or clinics for non-COVID-19-related reasons from April 2020 through April 2021 for SARS-CoV-2 antibodies. We used univariable and multivariable regression models to determine the association between seropositivity and participant characteristics.

RESULTS

Among 2357 participants, seroprevalence rose from 7.9% in April/May 2020 (95% CI, 4.9-10.9) to 25.0% in April 2021 (95% CI, 21.5-28.5). Hispanic and black children had a higher association with antibody positivity than non-Hispanic and white children, respectively, in multiple sampling periods.

CONCLUSIONS

By spring 2021, most children in Arkansas were not infected with SARS-CoV-2. With the emergence of SARS-CoV-2 variants, recognition of long-term effects of COVID-19, and the lack of an authorized pediatric SARS-CoV-2 vaccine at the time, these results highlight the importance of including children in SARS-CoV-2 public health, clinical care, and research strategies.

SARS-CoV-2 antibody prevalence in a pediatric cohort of unvaccinated children in Mérida, Yucatán, México

The prevalence of SARS-CoV-2 exposure in children during the global COVID-19 pandemic has been underestimated due to lack of testing and the relatively mild symptoms in adolescents. Understanding the exposure rates in the pediatric population is essential as children are the last to receive vaccines and can act as a source for SARS-CoV-2 mutants that may threaten vaccine escape. This cross-sectional study aims to quantify the prevalence of anti-SARS-CoV-2 serum antibodies in children in a major city in México in the Spring of 2021 and determine if there are any demographic or socioeconomic correlating factors. We obtained socioeconomic information and blood samples from 1,005 children from 50 neighborhood clusters in Mérida, Yucatán, México. We then tested the sera of these participants for anti-SARS-CoV-2 IgG and IgM antibodies using lateral flow immunochromatography. We found that 25.5% of children in our cohort were positive for anti-SARS-CoV-2 antibodies and there was no correlation between age and antibody prevalence. Children that lived with large families were statistically more likely to have antibodies against SARS-CoV-2. Spatial analyses identified two hotspots of high SARS-CoV-2 seroprevalence in the west of the city. These results indicate that a large urban population of unvaccinated children has been exposed to SARS-CoV-2 and that a major correlating factor was the number of people within the child's household with a minor correlation with particular geographical hotspots. There is also a larger population of children that may be susceptible to future infection upon easing of social distancing measures. These findings suggest that in future pandemic scenarios, limited public health resources can be best utilized on children living in large households in urban areas.

Cross-sectional seroprevalence surveys of SARS-CoV-2 antibodies in children in Germany, June 2020 to May 2021

The rate of SARS-CoV-2 infections in children remains unclear due to many asymptomatic cases. We present a study of cross-sectional seroprevalence surveys of anti-SARS-CoV-2 IgG in 10,358 children recruited in paediatric hospitals across Germany from June 2020 to May 2021. Seropositivity increased from 2.0% (95% CI 1.6, 2.5) to 10.8% (95% CI 8.7, 12.9) in March 2021 with little change up to May 2021. Rates increased by migrant background (2.8%, 4.4% and 7.8% for no, one and two parents born outside Germany). Children under three were initially 3.6 (95% CI 2.3, 5.7) times more likely to be seropositive with levels equalising later. The ratio of seropositive cases per recalled infection decreased from 8.6 to 2.8. Since seropositivity exceeds the rate of recalled infections considerably, serologic testing may provide a more valid estimate of infections, which is required to assess both the spread and the risk for severe outcomes of SARS-CoV-2 infections.

Children are less likely to be infected with SARS-CoV-2 and develop less severe disease than adults, which makes estimation of infection rates challenging. Here, the authors conduct seroprevalence surveys of children in Germany, describe changes in prevalence over time, and identify risk factors for infection.

Validation of Serological Methods for COVID-19 and Retrospective Screening of Health Employees and Visitors to the São Paulo University Hospital, Brazil

Reliable serological tests for the detection of SARS-CoV-2 antibodies among infected or vaccinated individuals are important for epidemiological and clinical studies. Low-cost approaches easily adaptable to high throughput screenings, such as Enzyme-Linked Immunosorbent Assays (ELISA) or electrochemiluminescence immunoassay (ECLIA), can be readily validated using different SARS-CoV-2 antigens. A total of 1,119 serum samples collected between March and July of 2020 from health employees and visitors to the University Hospital at the University of São Paulo were screened with the Elecsys® Anti-SARS-CoV-2 immunoassay (Elecsys) (Roche Diagnostics) and three in-house ELISAs that are based on different antigens: the Nucleoprotein (N-ELISA), the Receptor Binding Domain (RBD-ELISA), and a portion of the S1 protein (ΔS1-ELISA). Virus neutralization test (CPE-VNT) was used as the gold standard to validate the serological assays. We observed high sensitivity and specificity values with the Elecsys (96.92% and 98.78%, respectively) and N-ELISA (93.94% and 94.40%, respectively), compared with RBD-ELISA (90.91% sensitivity and 88.80% specificity) and the ΔS1-ELISA (77.27% sensitivity and 76% specificity). The Elecsys® proved to be a reliable SARS-CoV-2 serological test. Similarly, the recombinant SARS-CoV-2 N protein displayed good performance in the ELISA tests. The availability of reliable diagnostic tests is critical for the precise determination of infection rates, particularly in countries with high SARS-CoV-2 infection rates, such as Brazil. Collectively, our results indicate that the development and validation of new serological tests based on recombinant proteins may provide new alternatives for the SARS-CoV-2 diagnostic market.

SARS-CoV-2 Viral Incidence, Antibody Point Prevalence, Associated Population Characteristics, and Vaccine Attitudes, South Carolina, February 2021

The SARS-CoV-2 outbreak from October 2020 through February 2021 was the largest outbreak as of February 2021, and timely information on current representative prevalence, vaccination, and loss of prior antibody protection was unknown. In February 2021, the South Carolina Department of Health and Environmental Control conducted a random sampling point prevalence investigation consisting of viral and antibody testing and an associated health survey, after selecting participants aged ≥5 years using a population proportionate to size of South Carolina residents. A total of 1917 residents completed a viral test, 1803 completed an antibody test, and 1463 completed ≥1 test and a matched health survey. We found an incidence of 2.16 per 100 residents and seroprevalence of 16.4% among South Carolina residents aged ≥5 years. Undetectable immunoglobulin G and immunoglobulin M antibodies were noted in 28% of people with a previous positive test result, highlighting the need for targeted education among people who may be susceptible to reinfection. We also found a low rate of vaccine hesitancy in the state (13%). The results of this randomly selected surveillance and associated health survey have important implications for prospective COVID-19 public health response efforts. Most notably, this article provides a feasible framework for prompt rollout of a statewide evidence-based surveillance initiative.

The SARS-CoV-2 pandemic in Germany may represent the sum of a large number of local but independent epidemics each initiated by individuals aged 10 - 19 years, middle aged males, or elderly individuals

Many epidemiological aspects of the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) pandemics, particularly those affecting children, are still sparsely elucidated. Data on the first pandemic phase during the year 2020 indicated that children might serve as a virus reservoir. We now analyzed data on more than 530 000 SARS‐CoV‐2 polymerase chain reaction (PCR) and 12 503 anti‐SARS‐CoV‐2 antibody tests performed in the west of Germany until Week 4 of 2021. We show that children of at least 10 years of age may play a prominent role in the pandemic showing highest PCR‐positive rates in the first (Weeks 28–35), second (Weeks 42–48), and third wave (Week 50 of 2020–Week 2 2021) of the second pandemic phase, although the waves were not mainly initiated by children. The waves' kinetics differed even in nearby cities. Low PCR‐positive rates were confined to areas of lower population density. PCR‐positive rates were higher among middle‐aged males compared with women and among very old females compared with males. From Week 25, seroprevalence rates slowly increased to 50%, indicating ongoing virus activity. In conclusion, the SARS‐CoV‐2 pandemics is characterized by many local but interacting epidemics, initiated and driven by different social groups. Children may not be the main initiators of virus spreading but older children may significantly affect the course of the pandemic. High population density is associated with higher SARS‐CoV‐2 incidence.

Comparison of SARS-CoV-2 Antibodies and Six Immunoassays in Pediatric and Adult Patients 12 Weeks After COVID-19

Introduction

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific humoral immune persistence has been proposed to be affected by patients’ characteristics. Moreover, available conflicting assay results are needed to be settled through comparative research with defined clinical specimens.

Methods

This prospective study investigated SARS-CoV-2-specific antibodies among 43 adults and 34 children at a mean of 12 weeks after the onset of COVID-19 symptoms using six serological assays and compared their performance. We used two Euroimmun (Euroimmun, Luebeck, Germany), two automated Roche Elecsys (Basel, Switzerland), and two rapid immuno-chromatographic Ecotest (Matrix Diagnostics, Assure Tech. (Hangzhou) Co., L, China) assays to investigate SARS-CoV-2 antibodies.

Results

The findings showed that the Roche Elecsys anti-S total test yielded the best positivity/sensitivity (children 94.1% and adults 93.0%; p = 0.877) while five immunoglobulin IgG targeting assays had similar positivity/sensitivity between children (88.2% to 94.1%) and adults (88.4% to 93.0%) (p > 0.05). Although IgM positivity was relatively low (p < 0.001), it was found in the majority of our pediatric and adult patients (67.6% and 86.0%, respectively; p = 0.098). SARS-CoV-2 S IgG titers were found to be higher among males in pediatric and adult groups compared to females (p = 0.027 and p = 0.041, respectively). Furthermore, we observed significantly higher antibody titers among pneumonia patients (p = 0.001).

Conclusion

Overall, we concluded SARS-CoV-2 antibody persistence over an average of 12 weeks after the onset of COVID-19 symptoms. While automated Roche Elecsys total antibody assays yielded the best sensitivity (> 90%) and five assays targeting IgG had acceptable performance. Patients with pneumonia and males have higher antibody titers. The effect of antibody persistence on re-infections should be monitored in longitudinal studies.

Seroepidemiology of SARS-CoV-2 in pediatric population during a 16-month period prior to vaccination

Limited prospective serosurveillance data in children regarding severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection have been reported. We prospectively investigated SARS‐CoV‐2 seropositivity in children during a 16‐month period of the coronavirus disease 2019 (COVID‐19) pandemic, including the four waves of the pandemic, before SARS‐CoV‐2 adolescents' vaccination. Serum samples from children admitted to the major tertiary Greek pediatric hospital for any cause, except for COVID‐19 infection, were randomly collected from 05/2020 to 08/2021. The study period was divided into four 4‐month periods representing relevant epidemic waves. Total SARS‐CoV‐2 antibodies for nucleocapsid protein were determined using the Elecsys® Anti‐SARS‐CoV‐2 reagent. A total of 3099 children (0–16 years) were included in the study. A total of 344 (11.1%) seropositive children were detected (males: 205 [59.5%]; median age [interquartile range [IQR]]: 3 years [0.6–10]). Seropositivity rates (%) increased during the four 4‐month periods: 1.4%, 8.6%, 17.2%, and 17.6%, respectively. A correlation of seropositivity rates in children with new diagnosed SARS‐CoV‐2 cases in the community was detected. No significant differences were detected between males and females. Seropositivity was significantly higher in hospitalized than in nonhospitalized children and in non‐Greek compared to Greek children (p < 0.001). The lowest seropositivity rate before school opening (9/2021) was detected in the age groups 6–12 years (14.4%) and 12–16 years (16.1%). However, compared with the other age groups, the lowest median antibody titers were observed in children 0–1 year (median [IQR]: 13.9 cut‐off index: [4.5–53.9] [p < 0.001]). Although the seropositivity of children was related to the community epidemic waves, the exposure was limited. Low seropositivity rates in school‐age children support the need for SARS‐CoV‐2 immunization.

SARS‐CoV‐2 seropositivity rates (%) in children residing in Athens increased from 05/2020 to 08/2021 during the four 4‐month pandemic waves: 1.4%, 8.6%, 17.2%, and 17.6%, respectively.

A correlation of seropositivity rates in children with new diagnosed SARS‐CoV‐2 cases in the community was detected.

The lowest seropositivity rate before school opening (9/2021) was detected in the age groups 6–12 years (14.4%) and 12–16 years (16.1%).

Limited exposure and low seropositivity rates in school‐age children support the need for SARS‐CoV‐2 immunization.

Incidence Rates, Household Infection Risk, and Clinical Characteristics of SARS-CoV-2 Infection Among Children and Adults in Utah and New York City, New York

IMPORTANCE

Data about the risk of SARS-CoV-2 infection among children compared with adults are needed to inform COVID-19 risk communication and prevention strategies, including COVID-19 vaccination policies for children.

OBJECTIVE

To compare incidence rates and clinical characteristics of SARS-CoV-2 infection among adults and children and estimated household infection risks within a prospective household cohort.

DESIGN, SETTING, AND PARTICIPANTS

Households with at least 1 child aged 0 to 17 years in selected counties in Utah and New York City, New York, were eligible for enrollment. From September 2020 through April 2021, participants self-collected midturbinate nasal swabs for reverse transcription-polymerase chain reaction testing for SARS-CoV-2 and responded to symptom questionnaires each week. Participants also self-collected additional respiratory specimens with onset of COVID-19-like illness. For children unable to self-collect respiratory specimens, an adult caregiver collected the specimens.

MAIN OUTCOMES AND MEASURES

The primary outcome was incident cases of any SARS-CoV-2 infection, including asymptomatic and symptomatic infections. Additional measures were the asymptomatic fraction of infection calculated by dividing incidence rates of asymptomatic infection by rates of any infection, clinical characteristics of infection, and household infection risks. Primary outcomes were compared by participant age group.

RESULTS

A total of 1236 participants in 310 households participated in surveillance, including 176 participants (14%) who were aged 0 to 4 years, 313 (25%) aged 5 to 11 years, 163 (13%) aged 12 to 17 years, and 584 (47%) 18 years or older. Overall incidence rates of SARS-CoV-2 infection were 3.8 (95% CI, 2.4-5.9) and 7.7 (95% CI, 4.1-14.5) per 1000 person-weeks among the Utah and New York City cohorts, respectively. Site-adjusted incidence rates per 1000 person-weeks were similar by age group: 6.3 (95% CI, 3.6-11.0) for children 0 to 4 years, 4.4 (95% CI, 2.5-7.5) for children 5 to 11 years, 6.0 (95% CI, 3.0-11.7) for children 12 to 17 years, and 5.1 (95% CI, 3.3-7.8) for adults (≥18 years). The asymptomatic fractions of infection by age group were 52%, 50%, 45%, and 12% among individuals aged 0 to 4 years, 5 to 11 years, 12 to 17 years, and 18 years or older, respectively. Among 40 households with 1 or more SARS-CoV-2 infections, the mean risk of SARS-CoV-2 infection among all enrolled household members was 52% (range, 11%-100%), with higher risks in New York City compared with Utah (80% [95% CI, 64%-91%] vs 44% [95% CI, 36%-53%]; P < .001).

CONCLUSIONS AND RELEVANCE

In this study, children had similar incidence rates of SARS-CoV-2 infection compared with adults, but a larger proportion of infections among children were asymptomatic.

SARS-CoV-2 seroprevalence in children and their family members, July-October 2020, Brussels

The aim of this study was to estimate the seroprevalence of SARS-CoV-2 antibodies in a pediatric population after the first pandemic wave in Belgium. All patients requiring a blood sample between 1 July 2020 and 31 October 2020 in our institution were invited to participate. Their parents and siblings could also participate to estimate familial transmission and the congruence between serological statuses. A questionnaire was completed for each participant to identify symptoms consistent with COVID-19 in the previous months. Blood samples were tested for SARS-CoV-2-specific immunoglobulin G using ELISA. The final population included 112 children, 24 siblings of these children, and 36 adults. The seroprevalence of cases was 6.9% before 8 September, a date that corresponds to 1 week after the beginning of the second wave in Belgium and 22.5% afterwards (OR = 3.89, 95% CI (1.20; 12.58), p-value = 0.03). Twenty-five percent of children were asymptomatic, and none experienced severe disease. The symptoms associated with SARS-CoV-2-positive antibodies were diarrhoea (OR = 9.9, 95% CI [2.88; 33.87.65] p-value < 0.01), fever (OR = 3.8, 95% CI [1.44; 10.22] p-value < 0.01), rhinitis (OR = 3.9, 95% CI [1.38; 10.90] p-value = 0.01), or anosmia (OR = 31.5, 95% CI [1.45; 682.7], p-value = 0.02). A child was the first symptomatic household member in 50% of the familial clusters.Conclusion: Seroprevalence in children was comparable to that of the general population. Children could represent the source of infection in the household. What is Known: • COVID-19 infection is generally mild or asymptomatic in children and adolescents. • Belgian strategy of testing was focused on symptoms. • Adults are believed to be responsible for most of familial clusters. What is New: • Serological testing gives a more accurate view of the rate of infected children. • Based on serological results, children have been infected as frequently as adults during the first and second wave in Belgium. • Seventy-five percent of SARS-CoV-2 IgG-positive children presented a mild symptomatology, and 25% were totally asymptomatic. • Children could represent the source of infection within household.

Public health impact of the Pfizer-BioNTech COVID-19 vaccine (BNT162b2) in the first year of rollout in the United States

BACKGROUND

As the body of evidence on COVID-19 and post-vaccination outcomes continues to expand, this analysis sought to evaluate the public health impact of the Pfizer-BioNTech COVID-19 Vaccine, BNT162b2, during the first year of its rollout in the US.

METHODS

A combined Markov decision tree model compared clinical and economic outcomes of the Pfizer-BioNTech COVID-19 Vaccine (BNT162b2) versus no vaccination in individuals aged ≥12 years. Age-stratified epidemiological, clinical, economic, and humanistic parameters were derived from existing data and published literature. Scenario analysis explored the impact of using lower and upper bounds of parameters on the results. The health benefits were estimated as the number of COVID-19 symptomatic cases, hospitalizations and deaths averted, and Quality Adjusted Life Years (QALYs) saved. The economic benefits were estimated as the amount of healthcare and societal cost savings associated with the vaccine-preventable health outcomes.

RESULTS

It was estimated that, in 2021, the Pfizer-BioNTech COVID-19 Vaccine (BNT162b2) contributed to averting almost 9 million symptomatic cases, close to 700,000 hospitalizations, and over 110,000 deaths, resulting in an estimated $30.4 billion direct healthcare cost savings, $43.7 billion indirect cost savings related to productivity loss, as well as discounted gains of 1.1 million QALYs. Scenario analyses showed that these results were robust; the use of alternative plausible ranges of parameters did not change the interpretation of the findings.

CONCLUSIONS

The Pfizer-BioNTech COVID-19 Vaccine (BNT162b2) contributed to generate substantial public health impact and vaccine-preventable cost savings in the first year of its rollout in the US. The vaccine was estimated to prevent millions of COVID-19 symptomatic cases and thousands of hospitalizations and deaths, and these averted outcomes translated into cost-savings in the billions of US dollars and thousands of QALYs saved. As only direct impacts of vaccination were considered, these estimates may be conservative.

COVID-19 in Children: Where do we Stand?

From the beginning of the coronavirus disease 2019 (COVID-19) pandemic it became evident that children infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remain mostly asymptomatic or mildly symptomatic. We reviewed the epidemiologic and clinical features of children with SARS-CoV-2 infection. The true prevalence of asymptomatic SARS-CoV-2 infection is most likely underestimated, as asymptomatic children are less frequently tested. Serologic surveys indicate that half of children tested positive for SARS-CoV-2 report no symptoms. Anosmia/ageusia is not frequent in children but it is the strongest predictor of a positive SARS-CoV-2 test. In general, children with COVID-19 are at lower risk of hospitalization and life-threatening complications. Nevertheless, cases of severe disease or a post-infectious multisystem hyperinflammatory syndrome named multisystem inflammatory syndrome in children (MIS-C) have been described. Rarely children with severe COVID-19 develop neurologic complications. In addition, studies indicate that school closures have a limited impact on SARS-CoV-2 transmission, much less than other social distancing measures. The past months new SARS-CoV-2 variants emerged with higher transmissibility and an increased impact on morbidity and deaths. The role of children in the transmission dynamics of these variants must be elucidated. Lastly, preliminary results from COVID-19 vaccine trials indicate very good efficacy and tolerability in children. Very recently the United States Centers for Disease Control and Prevention and other public health authorities recommend vaccination of children 12 years or older to protect them but mostly to contribute to the achievement of herd immunity.

Impact of information framing and vaccination characteristics on parental COVID-19 vaccine acceptance for children: a discrete choice experiment

This study aimed to test the influence of vaccination characteristics and gain/loss-framing of information, on parental acceptance of the coronavirus disease 2019 (COVID-19) vaccination for their minor children. A discrete choice experiment was conducted among parents of children aged 0-17 years from September to October 2021 in Hong Kong. Respondents were randomly assigned to four groups with different framing of information and asked to choose hypothetical vaccination alternatives, described by seven attributes that were derived from prior qualitative interviews. A mixed logit model was adopted to analyze the effect of attributes and information framing on parental vaccination acceptance. The vaccine acceptance rates under different scenarios were also estimated. A total of 298 valid responses were obtained. It was found that the BioNTech brand, higher efficacy, less serious adverse events and more vaccination coverage in children significantly improved parental acceptance. Additionally, loss-framing increased parental acceptance compared with gain-framing, while the presentation of mortality information did not make a difference. Acceptance was also associated with parental uptake of the COVID-19 vaccine and the children's age.

CONCLUSION

The findings imply that factors including gain/loss information framing, importance of vaccine characteristics, and peer influence have a significant effect on parents' decisions to get their children vaccinated. Parents with younger children had greater vaccine hesitancy, and information framing techniques should be considered in vaccination promotion for combating such vaccine hesitancy. Future studies could be conducted to identify the moderators and mediators of information framing to facilitate its implementation.

WHAT IS KNOWN

• Parental acceptance of COVID-19 vaccine was found to be associated with various socio-economic and psychosocial factors, while the evidence on impact of vaccination characteristics was limited. • Behavioral interventions, including information framing, have been used to promote various health behaviors.

WHAT IS NEW

• Loss-framing of information on vaccine effectiveness improves vaccine acceptance, while additional information on how the vaccine reduces death does not make a difference, which can be used to inform communication with the public in vaccination promotion. • The social norm (i.e., the vaccine uptake amongst other people) is important for increasing the parental vaccine acceptance rate.

[Seroprevalence of SARS-CoV-2 among children and adolescents in Germany-an overview]

Hintergrund

SARS-CoV-2-Antikörperstudien ergänzen und erweitern die Erkenntnisse aus der Meldestatistik laborbestätigter COVID-19-Fälle um Informationen zu unentdeckten Fällen.

Ziel der Arbeit

Der vorliegende Beitrag fasst bisherige Ergebnisse zur SARS-CoV-2-Prävalenz aus seroepidemiologischen Studien in Deutschland zusammen, die sich auf Kinder und Jugendliche konzentrieren, und ergänzt die bereits vorliegende Übersicht zur Seroprävalenz bei Erwachsenen und speziell bei Blutspendenden in Deutschland.

Material und Methoden

Die Ergebnisse der Übersichtsarbeit beruhen auf einer fortlaufenden systematischen Recherche in Studienregistern, Literaturdatenbanken, von Preprint-Veröffentlichungen und Medienberichten seroepidemiologischer Studien in Deutschland sowie deren Ergebnissen.

Ergebnisse

Mit Stand 17.09.2021 sind uns 16 deutsche seroepidemiologische Studien, die sich auf Kinder und Jugendliche konzentrieren, bekannt geworden. Für 9 dieser Studien liegen Ergebnisse vor. Für fast alle untersuchten Settings lag die SARS-CoV-2-Seroprävalenz für Kinder im Kita- und Grundschulalter in der ersten COVID-19-Welle deutlich unter 1 % und für Jugendliche unter 2 %. Im Verlauf der Pandemie wurden höhere Seroprävalenzen von bis zu 8 % für Kinder im Grundschulalter ermittelt.

Diskussion

Ergebnisse von SARS-CoV-2-Antikörperstudien bei Kindern und Jugendlichen in Deutschland liegen bislang erst in geringem Umfang und basierend auf lokal-regionalen, nichtrepräsentativen Stichproben vor. In künftigen Studien gilt es, einerseits abzuschätzen, welcher Anteil der Kinder und Jugendlichen bereits eine Infektion hatte oder geimpft ist. Zum anderen gilt es, die Verbreitung körperlicher und psychischer Beeinträchtigungen im Nachgang einer Infektion zu untersuchen.

GPS-estimated foot traffic data and venue selection for COVID-19 serosurveillance studies

The initial phase of the COVID-19 pandemic in the US was marked by limited diagnostic testing, resulting in the need for seroprevalence studies to estimate cumulative incidence and define epidemic dynamics. In lieu of systematic representational surveillance, venue-based sampling was often used to rapidly estimate a community’s seroprevalence. However, biases and uncertainty due to site selection and use of convenience samples are poorly understood. Using data from a SARS-CoV-2 serosurveillance study we performed in Somerville, Massachusetts, we found that the uncertainty in seroprevalence estimates depends on how well sampling intensity matches the known or expected geographic distribution of seropositive individuals in the study area. We use GPS-estimated foot traffic to measure and account for these sources of bias. Our results demonstrated that study-site selection informed by mobility patterns can markedly improve seroprevalence estimates. Such data should be used in the design and interpretation of venue-based serosurveillance studies.

SARS CoV-2 seroprevalence in a US school district during COVID-19

Reduced symptomatology and access to testing in children have led to underestimates of paediatric COVID-19 prevalence and raised concerns about school safety. To explore COVID-19 prevalence and risk factors in school settings, we conducted a SARS-CoV-2 serosurvey in a Vermont, USA school district in December 2020. Among 336 students (63%) and 196 teachers/staff (37%), adjusted seroprevalence was 4.7% (95% CI 2.9 to 7.2) and was lowest in preK-5 students (4-10 Years). Seroprevalence was 10-fold higher than corresponding state PCR data but was low overall with no evidence of onward transmissions. These results further support feasibility of in-person learning during COVID-19 with appropriate mitigation measures.