Longitudinal survey of humoral and cellular response to SARS-CoV-2 infection in children.

BACKGROUND: Data regarding humoral and cellular response against SARS-CoV-2 in children are scarce. We analysed seroconversion rate, decrease of anti-RBD IgG antibodies over time and T-cell response in paediatric patients who suffered COVID-19. METHODS: Longitudinal study of paediatric patients COVID-19 diagnosed by positive molecular assay in nasopharyngeal swabs. Blood samples were drawn 1-2 months and 6-7 months after acute infection. Anti-RBD IgG were determined using the Alinity® SARS-CoV-2 IgG II Quant assay (Abbott). Cellular immune response was analysed by T-SPOT® SARS-CoV-2 assay kit (Oxford Immunotec Ltd.). RESULTS: 27/39 (69,2%) patients seroconverted. Despite a significant decrease in antibody levels over time (p < 0,01), no children seroreverted between first and second visits. Only 6/16 (37,2%) children under 6 years-old were seropositive compared to 21/23 (91,3%) over 6 years-old (p < 0,01). Highest antibody levels were found in seropositive younger children (p = 0,036). Thirteen (33,3%) children showed T-cell response. Among participants showing humoral response, no cellular response was detected in 14 (51,9%). CONCLUSIONS: Anti-RBD IgG antibodies persistence at 6-7-months after SARS-CoV-2 infection was observed. A different IgG response was found depending on age. As measured by T-SPOT, most patients did not display cellular response 6-7 months after infection.

SARS-CoV-2 Infection in Children and Adolescents Living With HIV in Madrid.

Multicenter study designed to describe epidemiologic and clinical characteristics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positive cases registered among children and adolescents living with HIV (CALWH). SARS-CoV-2 infection was confirmed in 13.3% of CALWH, with all patients presenting mild symptoms, and the outcome was good in all patients. None of the HIV- and antiretroviral treatment-related variables studied were associated with greater infection risk or could be considered protective.

Oral saliva swab reverse transcription PCR for Covid-19 in the paediatric population.

OBJECTIVES: To evaluate the performance of oral saliva swab (OSS) reverse transcription PCR (RT-PCR) compared with RT-PCR and antigen rapid diagnostic test (Ag-RDT) on nasopharyngeal swabs (NPS) for SARS-CoV-2 in children. DESIGN: Cross-sectional multicentre diagnostic study. SETTING: Study nested in a prospective, observational cohort (EPICO-AEP) performed between February and March 2021 including 10 hospitals in Spain. PATIENTS: Children from 0 to 18 years with symptoms compatible with Covid-19 of ≤5 days of duration were included. Two NPS samples (Ag-RDT and RT-PCR) and one OSS sample for RT-PCR were collected. MAIN OUTCOME: Performance of Ag-RDT and RT-PCR on NPS and RT-PCR on OSS sample for SARS-CoV-2. RESULTS: 1174 children were included, aged 3.8 years (IQR 1.7-9.0); 73/1174 (6.2%) patients tested positive by at least one of the techniques. Sensitivity and specificity of OSS RT-PCR were 72.1% (95% CI 59.7 to 81.9) and 99.6% (95% CI 99 to 99.9), respectively, versus 61.8% (95% CI 49.1 to 73) and 99.9% (95% CI 99.4 to 100) for the Ag-RDT. Kappa index was 0.79 (95% CI 0.72 to 0.88) for OSS RT-PCR and 0.74 (95% CI 0.65 to 0.84) for Ag-RDT versus NPS RT-PCR. CONCLUSIONS: RT-PCR on the OSS sample is an accurate option for SARS-CoV-2 testing in children. A less intrusive technique for younger patients, who usually are tested frequently, might increase the number of patients tested.

A Prospective Study of the Serological, Clinical, and Epidemiological Features of a SARS-CoV-2 Positive Pediatric Cohort.

BACKGROUND: SARS-CoV-2 was a global pandemic. Children develop a mild disease and may have a different rate of seroconversion compared to adults. The objective was to determine the number of seronegative patients in a pediatric cohort. We also reviewed the clinical-epidemiological features associated with seroconversion. METHODS: A multicenter prospective observational study during September-November 2020, of COVID-19, confirmed by reverse transcription-polymerase chain reaction. Data were obtained 4-8 weeks after diagnosis. Blood samples were collected to investigate the humoral response, using three different serological methods. RESULTS: A total of 111 patients were included (98 symptomatic), 8 were admitted to hospital, none required an Intensive Care Unit visit. Median age: 88 months (IQR: 24-149). Median time between diagnosis and serological test: 37 days (IQR: 34-44). A total of 19 patients were non-seroconverters when using three serological techniques (17.1%; 95% CI: 10.6-25.4); most were aged 2-10 years (35%, p < 0.05). Univariate analysis yielded a lower rate of seroconversion when COVID-19 confirmation was not present amongst household contacts (51.7%; p < 0.05). CONCLUSIONS: There was a high proportion of non-seroconverters. This is more commonly encountered in childhood than in adults. Most seronegative patients were in the group aged 2-10 years, and when COVID-19 was not documented in household contacts. Most developed a mild disease. Frequently, children were not the index case within the family.

Clinical characteristics of children hospitalized for COVID-19.

Introduction: Most SARS-CoV2 infections in the pediatric population are asymptomatic or with mild symptoms, with a minimal proportion of severe cases described as SARS-CoV2-associated multi-system inflammatory syndrome (MIS-C).The objective was to describe the clinical and epidemiological characteristics of pediatric patients admitted with confirmed diagnosis of SARS-CoV2 infection from the beginning of the pandemic until May 2021. Methods: Retrospective observational study of pediatric patients hospitalized with confirmed COVID-19, in a tertiary hospital. Epidemiological and clinical data, additional tests, treatments administered and evolution were collected. Results: 30 patients were included, classified into 3 groups according to diagnosis: respiratory infection, MIS-C and compatible symptoms. The patients with pneumonia were associated with age older, comorbidities and lymphopenia. MIS-C were more serious patients, with marked laboratory involvement and greater admission to PICU. Most of these were secondary cases of contact in the family environment. Discussion: The most frequent clinical manifestations of COVID-19 in children are mild-moderate respiratory with good evolution. MIS-C is another form of expression of SARS-COV2 infection of greater severity, but usually with good prognosis after early diagnosis and frequent PICU admission.

Introducción: La mayoría de infecciones por SARS-CoV2 en población pediátrica cursan asintomáticas o con síntomas leves, con porcentaje mínimo de casos graves descritos como síndrome inflamatorio multisistémico asociado al SARS-CoV2 (SIM-PEDs).El objetivo fue describir las características clínico epidemiológicas de aquellos pacientes pediátricos ingresados, con diagnóstico confirmado de SARS-CoV2 desde el inicio de la pandemia hasta mayo 2021. Métodos: Estudio retrospectivo observacional de pacientes pediátricos ingresados con diagnóstico de COVID-19, de un hospital terciario. Se recogieron datos demográficos, clínicos, pruebas complementarias, tratamiento administrado y evolución. Resultados: Se incluyeron 30 pacientes, clasificándose en 3 grupos según diagnóstico: Infección respiratoria, SIM-PEDs y síntomas compatibles. Los pacientes con neumonía asociaban mayor edad, comorbilidades y linfopenia. SIM-PEDs fueron pacientes más graves, con afectación analítica marcada y mayor ingreso en UCIP. La mayoría eran casos secundarios de contacto en el entorno familiar. Discusión: Los cuadros clínicos de COVID-19 más frecuentes en niños son respiratorios leves-moderados con buena evolución. SIM-PEDs es otra forma de expresión de infección por SARS-COV2 de mayor gravedad, pero habitualmente con buen pronóstico tras diagnóstico precoz y requiriendo frecuentemente ingreso en UCIP.

Clinical characteristics of children hospitalized for COVID-19⋆ Características clínicas de los niños hospitalizados por COVID-19

Introduction Most SARS-CoV2 infections in the pediatric population are asymptomatic or with mild symptoms, with a minimal proportion of severe cases described as SARS-CoV2-associated multi-system inflammatory syndrome (MIS-C). The objective was to describe the clinical and epidemiological characteristics of pediatric patients admitted with confirmed diagnosis of SARS-CoV2 infection from the beginning of the pandemic until May 2021. Methods Retrospective observational study of pediatric patients hospitalized with confirmed COVID-19, in a tertiary hospital. Epidemiological and clinical data, additional tests, treatments administered and evolution were collected. Results 30 patients were included, classified into 3 groups according to diagnosis: respiratory infection, MIS-C and compatible symptoms. The patients with pneumonia were associated with age older, comorbidities and lymphopenia. MIS-C were more serious patients, with marked laboratory involvement and greater admission to PICU. Most of these were secondary cases of contact in the family environment. Discussion The most frequent clinical manifestations of COVID-19 in children are mild-moderate respiratory with good evolution. MIS-C is another form of expression of SARS-COV2 infection of greater severity, but usually with good prognosis after early diagnosis and frequent PICU admission.

A Bayesian Model to Predict COVID-19 Severity in Children.

BACKGROUND: We aimed to identify risk factors causing critical disease in hospitalized children with COVID-19 and to build a predictive model to anticipate the probability of need for critical care. METHODS: We conducted a multicenter, prospective study of children with SARS-CoV-2 infection in 52 Spanish hospitals. The primary outcome was the need for critical care. We used a multivariable Bayesian model to estimate the probability of needing critical care. RESULTS: The study enrolled 350 children from March 12, 2020, to July 1, 2020: 292 (83.4%) and 214 (73.7%) were considered to have relevant COVID-19, of whom 24.2% required critical care. Four major clinical syndromes of decreasing severity were identified: multi-inflammatory syndrome (MIS-C) (17.3%), bronchopulmonary (51.4%), gastrointestinal (11.6%), and mild syndrome (19.6%). Main risk factors were high C-reactive protein and creatinine concentration, lymphopenia, low platelets, anemia, tachycardia, age, neutrophilia, leukocytosis, and low oxygen saturation. These risk factors increased the risk of critical disease depending on the syndrome: the more severe the syndrome, the more risk the factors conferred. Based on our findings, we developed an online risk prediction tool (https://rserver.h12o.es/pediatria/EPICOAPP/, username: user, password: 0000). CONCLUSIONS: Risk factors for severe COVID-19 include inflammation, cytopenia, age, comorbidities, and organ dysfunction. The more severe the syndrome, the more the risk factor increases the risk of critical illness. Risk of severe disease can be predicted with a Bayesian model.