Comparison of Epidemiologic and Clinical COVID-19 Profiles in Children in Argentina, During Circulation of Original and Variant (Alpha, Gamma and Lambda) Strains.

BACKGROUND: Information on the impact of the different variants in children in Latin America is scarce. The objective of this study was to describe epidemiologic and clinical features of COVID-19 infection in children under 18 years of age in Argentina, comparing the periods before and after the circulation of new variants. METHODS: Observational, cross-sectional, multicentric, analytical study. All patients under 18 years of age with confirmed SARS-CoV-2 infection admitted at 22 healthcare centers were included. Two study periods were established: Period 1 (EW10-2020 to EW12-2021) for the Wuhan strain; Period 2 (EW13 to EW35 2021) for Alpha, Gamma, Delta and Lambda variants. FINDINGS: A total of 6330 confirmed cases were included. Period 1: 3575 (56.5%), period 2: 2755 (43.5%). During period 2, a lower number of asymptomatic cases was observed, while general, respiratory and neurologic signs and symptoms increased in all age groups. Oxygen therapy requirement was higher during the first period (36.7% vs 19.1%; P < 0.001). No significant differences were observed in the rates of severe or critical cases (6.3% vs 5,4%; P = 0.102), intensive care admission (2.1% vs 2%; P < 0.656) or case fatality (0.3% vs 0.5 %; P < 0.229). MIS-C cases occurred more frequently during the first period (1.9% vs 1.1%; P = 0.009). INTERPRETATION: The clinical spectrum of COVID-19 in Argentina has evolved. With the emergence of new variants, although the number of asymptomatic cases declined, numbers of severe and critical cases, as well as case fatality rates in children, remained unchanged.

Vigilancia de virus sincicial respiratorio e influenza en niños escolarizados asistidos en un hospital pediátrico durante 2 meses del segundo semestre de 2021 / Respiratory syncytial virus and influenza surveillance in schoolchildren seen at a children's hospital over 2 months of the second semester of 2021

Introducción. Durante la pandemia de COVID-19, disminuyeron las notificaciones de infecciones respiratorias. El objetivo fue estimar la prevalencia de virus sincicial respiratorio (VSR) e influenza en niños escolarizados asistidos en un hospital pediátrico durante el retorno a la presencialidad. Métodos. Estudio transversal de casos sospechosos de COVID-19, de 3-18 años, con prueba negativa para SARSCoV-2, entre agosto y octubre de 2021. Se estratificó por nivel educativo. Se utilizó PCR para detectar VSR e influenza. Resultados. Se incluyeron 619 niños: 234 del nivel inicial, 224 del primario y 161 del secundario; 25,5 % (158) fueron positivos para VSR (36,3 % del nivel inicial versus 21 % del primario y 16 % del secundario); en adolescentes se asoció la infección al contacto escolar con caso sintomático (OR 2,5; IC95%: 1-6,80; p = 0,04). No se aisló virus influenza. Conclusión. VSR se aisló en un cuarto de la población estudiada, con mayor frecuencia en el nivel inicial; en adolescentes, se asoció con contacto escolar sintomático. No se detectaron casos de influenza

Introduction. Reporting of respiratory infections reduced during the COVID-19 pandemic. The objective was to estimate the prevalence of respiratory syncytial virus (RSV) and influenza in schoolchildren seen at a children's hospital during the return to school. Methods. Cross-sectional study of patients aged 3­18 years suspected of COVID-19 with a negative test for SARS-CoV-2 between August and October 2021. Participants were stratified by level of education. PCR was used to detect RSV and influenza. Results. A total of 619 children were included: 234 in preschool, 224 in primary and 161 in secondary school; 25.5% (158) tested positive for RS (36.3% in the pre-school level versus 21% in primary and 16% in secondary school). Infection among adolescents was associated with school contact with symptomatic cases (OR 2.5; 95%CI 1­6.80; p = 0.04). No case of influenza was detected. Conclusion. RSV was isolated in one fourth of the study population, with a higher frequency in pre-school; among adolescents, it was associated with school contact with symptomatic cases. No case of influenza was detected.

Respiratory syncytial virus and influenza surveillance in schoolchildren seen at a children's hospital over 2 months of the second semester of 2021. / Vigilancia de virus sincicial respiratorio e influenza en niños escolarizados asistidos en un hospital pediátrico durante 2 meses del segundo semestre de 2021.

INTRODUCTION: Reporting of respiratory infections reduced during the COVID-19 pandemic. The objective was to estimate the prevalence of respiratory syncytial virus(RSV) and influenza in schoolchildren seen at a children's hospital during the return to school. METHODS: Cross-sectional study of patients aged 3-18 years suspected of COVID-19 with a negative test for SARS-CoV-2 between August and October 2021. Participants were stratified by level of education. PCR was used to detect RSV and influenza. RESULTS: A total of 619 children were included: 234 in pre-school, 224 in primary and 161 in secondary school; 25.5% (158) tested positive for RSV (36.3% in the pre-school level versus 21% in primary and 16% in secondary school). Infection among adolescents was associated with school contact with symptomatic cases (OR 2.5; 95%CI 1-6.80; p = 0.04). No case of influenza was detected. CONCLUSIONS: RSV was isolated in one fourth of the study population, with a higher frequency in pre-school; among adolescents, it was associated with school contact with symptomatic cases. No case of influenza was detected.

Introducción. Durante la pandemia de COVID-19, disminuyeron las notificaciones de infecciones respiratorias. El objetivo fue estimar la prevalencia de virus sincicial respiratorio (VSR) e influenza en niños escolarizados asistidos en un hospital pediátrico durante el retorno a la presencialidad. Métodos. Estudio transversal de casos sospechosos de COVID-19, de 3-18 años, con prueba negativa para SARS-CoV-2, entre agosto y octubre de 2021. Se estratificó por nivel educativo. Se utilizó PCR para detectar VSR e influenza. Resultados. Se incluyeron 619 niños: 234 del nivel inicial, 224 del primario y 161 del secundario; 25,5 % (158) fueron positivos para VSR (36,3 % del nivel inicial versus 21 % del primario y 16 % del secundario); en adolescentes se asoció la infección al contacto escolar con caso sintomático (OR 2,5; IC95%: 1-6,80; p = 0,04). No se aisló virus influenza. Conclusión. VSR se aisló en un cuarto de la población estudiada, con mayor frecuencia en el nivel inicial; en adolescentes, se asoció con contacto escolar sintomático. No se detectaron casos de influenza.

Estudio multicéntrico de casos confirmados de COVID-19: datos preliminares de 2690 pacientes pediátricos en Argentina durante el primer año de la pandemia / A multicenter study of confirmed COVID-19 cases: preliminary data on 2690 pediatric patients in Argentina during the first year of the pandemic

Introducción. La evidencia actual indica que la gravedad de la enfermedad por el coronavirus 2019 (COVID-19, por su sigla en inglés) es menor en la población pediátrica, los datos locales aún son limitados. Objetivo: caracterizar los aspectos clínicos y epidemiológicos de la infección por COVID-19 en menores de 18 años en Argentina. Población y métodos. Estudio transversal, observacional y analítico de casos confirmados de COVID-19 entre 0 y 18 años asistidos entre marzo de 2020 y marzo de 2021 en 19 centros pediátricos de referencia de Argentina. Se realizó un análisis multivariado para identificar las variables predictoras de cuadros graves. Resultados. Se incluyeron 2690 casos de COVID-19: 77,7 % residentes del área metropolitana de Buenos Aires, 50,1 % de sexo masculino, mediana de edad de 5,6 años. El 90 % ocurrió entre las semanas epidemiológicas 20-47 del 2020; 60,4 % con antecedente de contacto con personas con COVID-19; y 96,6 % en el entorno familiar. El 51,4 % presentó síntomas respiratorios; 61,6 % síntomas generales; 18,8 % síntomas gastrointestinales; 17,1 % síntomas neurológicos; 7,2 % otros y 21,5 % fueron asintomáticos. El 59,4 % fue hospitalizado; 7,4 fueron graves o críticos. Se registraron 57 casos de síndrome inflamatorio multisistémico. El antecedente de asma, displasia broncopulmonar, cardiopatía congénita, desnutrición moderada a grave, obesidad, enfermedad neurológica crónica y/o edad menor de 6 meses resultaron predictores independientes de gravedad. Residir en barrios vulnerables resultó protector. Conclusiones. Más de la mitad de los casos refirieron antecedente de contacto con personas con COVID-19 en el entorno familiar. La hospitalización no respondió a criterios clínicos de gravedad. La gravedad se encuentra asociada a la existencia de ciertas comorbilidades.

Introduction. The current evidence indicates that the severity of the coronavirus disease 2019 (COVID-19) is lower in the pediatric population but local data are still limited. Objective: To characterize the clinical and epidemiological aspects of COVID-19 infection in patients younger than 18 years in Argentina. Population and methods. Cross-sectional, observational, and analytical study of confirmed COVID-19 patients aged 0-18 years seen between March 2020 and March 2021 at 19 referral children's hospitals of Argentina. A multivariate analysis was done to identify predictors of severe cases. Results. A total of 2690 COVID-19 cases were included: 77.7% lived in the Metropolitan Area of Buenos Aires; 50.1% were males; patients' median age was 5.6 years. Of them, 90% were seen during epidemiological weeks 20-47 of 2020; 60.4% had a history of contact with COVID-19 patients; and 96.6% in their family setting. Also, 51.4% had respiratory symptoms; 61.6%, general symptoms; 18.8%, gastrointestinal symptoms; 17.1%, neurological symptoms; 7.2%, other symptoms; and 21.5% were asymptomatic. In addition, 59.4% of patients were hospitalized and 7.4% had a severe or critical course. A total of 57 patients developed multisystem inflammatory syndrome. A history of asthma, bronchopulmonary dysplasia, congenital heart disease, moderate to severe malnutrition, obesity, chronic neurological disease and/or age younger than 6 months were independent predictors of severity.Livinginavulnerableneighborhoodwas a protective factor. Conclusions. More than half of cases referred a history of contact with COVID-19 patients in the family setting. Hospitalization was not based on clinical criteria of severity. Severity was associated with the presence of certain comorbidities

Impacto del COVID-19 en la circulación de virus respiratorios en un hospital pediátrico: una ausencia esperada / Impact of COVID-19 on the circulation of respiratory viruses in a children's hospital: an expected absence

Introducción. Los virus respiratorios son la principal causa de infección respiratoria aguda baja (IRAB) en la población pediátrica. En marzo de 2020, la Organización Mundial de la Salud declaró el estado de pandemia de la enfermedad por el nuevo coronavirus 2019 (COVID-19) con un impacto global elevado. El objetivo de este estudio fue describir el impacto de la pandemia de COVID-19 en las internaciones por IRAB en el Hospital de Niños Ricardo Gutiérrez (HNRG) y la circulación viral. Métodos. Estudio observacional, retrospectivo y descriptivo de pacientes internados por IRAB, comparando los años 2019 y 2020. Resultados. En 2020, la tasa de hospitalización por IRAB se redujo un 73 % en el HNRG (575,1/10 000 en 2019 y 155,3/10 000 en 2020). En 2019 se internaron 517 pacientes con IRAB; en 174 se identificaron los virus: sincicial respiratorio (71,2 %), adenovirus (AV) (10,3%), parainfluenza (PIF) (9,7 %) e influenza (FLU) (8,6 %). En 2020, se hospitalizaron 94 pacientes con IRAB. Hasta la semana epidemiológica (SE) 13 se registraron casos de IRAB por PIF y AV; en la SE 29 un caso de bronquiolitis por AV y rinovirus (RV), seguido de casos aislados de RV; no hubo IRAB por VSR ni por FLU. Se registraron 9 casos de IRAB por COVID-19: 2 bronquiolitis moderadas y 7 neumonías focales; con un adolescente fallecido por neumonía por COVID-19 con comorbilidades. En 2020, los casos presentaron mayor edad, más comorbilidades e internaciones previas en comparación con el 2019. La neumonía focal fue la presentación clínica predominante. Conclusión. En 2020, la tasa de hospitalización por IRAB se redujo significativamente en comparación con el año anterior, con ausencia de circulación de virus respiratorios estacionales en la población asistida en nuestro centro.

Introduction. Respiratory viruses are the main cause of acute lower respiratory tract infection (ALRTI) in the pediatric population. In March 2020, the World Health Organization declared that the new coronavirus disease 2019 (COVID-19) had reached the pandemic status. Our objective was to describe the impact of COVID-19 pandemic on hospitalizations due to ALRTI at Hospital de Niños Ricardo Gutiérrez (HNRG) and virus circulation. Methods. Observational, retrospective, and descriptive study of patients hospitalized due to ALRTI comparing 2019 and 2020. Results. In 2020, the rate of hospitalization due to ALRTI decreased by 73%. In 2019, 517 patients with ALRTI were hospitalized; the following viruses were identified in 174: respiratory syncytial virus (RSV) (71.2%), adenovirus (AV) (10.3%), parainfluenza virus (PIV) (9.7%), and influenza virus (FLU) (8.6%). In 2020, 94 patients with ALRTI were hospitalized. Until epidemiological week (EW) 13, cases of ALRTI due to PIV and AV were recorded; in EW 29, there was 1 case of bronchiolitis due to AV and rhinovirus (RV), followed by isolated cases of RV; no ALRTI due to RSV or FLU was recorded. In total, 9 cases of ALRTI due to COVID-19 were recorded: 2 moderate bronchiolitis and 7 focal pneumonia; 1 adolescent with comorbidities died due to COVID-19 pneumonia. In 2020, patients were older and had more comorbidities and prior hospitalizations compared to 2019. Focal pneumonia prevailed. Conclusion. In 2020, the rate of hospitalization due to ALRTI decreased significantly compared to 2019,with the absence of seasonal respiratory virus circulation in the pediatric population.

A multicenter study of confirmed COVID-19 cases: preliminary data on 2690 pediatric patients in Argentina during the first year of the pandemic. / Estudio multicéntrico de casos confirmados de COVID-19: datos preliminares de 2690 pacientes pediátricos en Argentina durante el primer año de la pandemia.

INTRODUCTION: The current evidence indicates that the severity of the coronavirus disease 2019 (COVID-19) is lower in the pediatric population but local data are still limited. Objective: To characterize the clinical and epidemiological aspects of COVID-19 infection in patients younger than 18 years in Argentina. POPULATION AND METHODS: Cross-sectional, observational, and analytical study of confirmed COVID-19 patients aged 0-18 years seen between March 2020 and March 2021 at 19 referral children's hospitals of Argentina. A multivariate analysis was done to identify predictors of severe cases. RESULTS: A total of 2690 COVID-19 cases were included: 77.7% lived in the Metropolitan Area of Buenos Aires; 50.1% were males; patients' median age was 5.6 years. Of them, 90% were seen during epidemiological weeks 20-47 of 2020; 60.4% had a history of contact with COVID-19 patients; and 96.6% in their family setting. Also, 51.4% had respiratory symptoms; 61.6%, general symptoms; 18.8%, gastrointestinal symptoms; 17.1%, neurological symptoms; 7.2%, other symptoms; and 21.5% were asymptomatic. In addition, 59.4% of patients were hospitalized and 7.4% had a severe or critical course. A total of 57 patients developed multisystem inflammatory syndrome. A history of asthma, bronchopulmonary dysplasia, congenital heart disease, moderate to severe malnutrition, obesity, chronic neurological disease and/or age younger than 6 months were independent predictors of severity. Living in a vulnerable neighborhood was a protective factor. CONCLUSIONS: More than half of cases referred a history of contact with COVID-19 patients in the family setting. Hospitalization was not based on clinical criteria of severity. Severity was associated with the presence of certain comorbidities.

Introducción. La evidencia actual indica que la gravedad de la enfermedad por el coronavirus 2019 (COVID-19, por su sigla en inglés) es menor en la población pediátrica, los datos locales aún son limitados. OBJETIVO: caracterizar los aspectos clínicos y epidemiológicos de la infección por COVID-19 en menores de 18 años en Argentina. Población y métodos. Estudio transversal, observacional y analítico de casos confirmados de COVID-19 entre 0 y 18 años asistidos entre marzo de 2020 y marzo de 2021 en 19 centros pediátricos de referencia de Argentina. Se realizó un análisis multivariado para identificar las variables predictoras de cuadros graves. RESULTADOS: Se incluyeron 2690 casos de COVID-19: 77,7 % residentes del área metropolitana de Buenos Aires, 50,1 % de sexo masculino, mediana de edad de 5,6 años. El 90 % ocurrió entre las semanas epidemiológicas 2047 del 2020; 60,4 % con antecedente de contacto con personas con COVID-19; y 96,6 % en el entorno familiar. El 51,4 % presentó síntomas respiratorios; 61,6 % síntomas generales; 18,8 % síntomas gastrointestinales; 17,1 % síntomas neurológicos; 7,2 % otros y 21,5 % fueron asintomáticos. El 59,4 % fue hospitalizado; 7,4 % fueron graves o críticos. Se registraron 57 casos de síndrome inflamatorio multisistémico. El antecedente de asma, displasia broncopulmonar, cardiopatía congénita, desnutrición moderada a grave, obesidad, enfermedad neurológica crónica y/o edad menor de 6 meses resultaron predictores independientes de gravedad. Residir en barrios vulnerables resultó protector. CONCLUSIONES: Más de la mitad de los casos refirieron antecedente de contacto con personas con COVID-19 en el entorno familiar. La hospitalización no respondió a criterios clínicos de gravedad. La gravedad se encuentra asociada a la existencia de ciertas comorbilidades.

Impact of COVID-19 on the circulation of respiratory viruses in a children's hospital: an expected absence. / Impacto del COVID-19 en la circulación de virus respiratorios en un hospital pediátrico: una ausencia esperada.

INTRODUCTION: Respiratory viruses are the main cause of acute lower respiratory tract infection (ALRTI) in the pediatric population. In March 2020, the World Health Organization declared that the new coronavirus disease 2019 (COVID-19) had reached the pandemic status. Our objective was to describe the impact of COVID-19 pandemic on hospitalizations due to ALRTI at Hospital de Niños Ricardo Gutiérrez (HNRG) and virus circulation. METHODS: Observational, retrospective, and descriptive study of patients hospitalized due to ALRTI comparing 2019 and 2020. RESULTS: In 2020, the rate of hospitalization due to ALRTI decreased by 73%. In 2019, 517 patients with ALRTI were hospitalized; the following viruses were identified in 174: respiratory syncytial virus (RSV) (71.2%), adenovirus (AV) (10.3%), parainfluenza virus (PIV) (9.7%), and influenza virus (FLU) (8.6%). In 2020, 94 patients with ALRTI were hospitalized. Until epidemiological week (EW) 13, cases of ALRTI due to PIV and AV were recorded; in EW 29, there was 1 case of bronchiolitis due to AV and rhinovirus (RV), followed by isolated cases of RV; no ALRTI due to RSV or FLU was recorded. In total, 9 cases of ALRTI due to COVID-19 were recorded: 2 moderate bronchiolitis and 7 focal pneumonia; 1 adolescent with comorbidities died due to COVID-19 pneumonia. In 2020, patients were older and had more comorbidities and prior hospitalizations compared to 2019. Focal pneumonia prevailed. CONCLUSIONS: In 2020, the rate of hospitalization due to ALRTI decreased significantly compared to 2019, with the absence of seasonal respiratory virus circulation in the pediatric population.

Introducción. Los virus respiratorios son la principal causa de infección respiratoria aguda baja (IRAB) en la población pediátrica. En marzo de 2020, la Organización Mundial de la Salud declaró el estado de pandemia de la enfermedad por el nuevo coronavirus 2019 (COVID-19) con un impacto global elevado. El objetivo de este estudio fue describir el impacto de la pandemia de COVID-19 en las internaciones por IRAB en el Hospital de Niños Ricardo Gutiérrez (HNRG) y la circulación viral. Métodos. Estudio observacional, retrospectivo y descriptivo de pacientes internados por IRAB, comparando los años 2019 y 2020. Resultados. En 2020, la tasa de hospitalización por IRAB se redujo un 73 % en el HNRG (575,1/10 000 en 2019 y 155,3/10 000 en 2020). En 2019 se internaron 517 pacientes con IRAB; en 174 se identificaron los virus: sincicial respiratorio (71,2%), adenovirus (AV) (10,3%), parainfluenza (PIF) (9,7 %) e influenza (FLU) (8,6 %). En 2020, se hospitalizaron 94 pacientes con IRAB. Hasta la semana epidemiológica (SE) 13 se registraron casos de IRAB por PIF y AV; en la SE 29 un caso de bronquiolitis por AV y rinovirus (RV), seguido de casos aislados de RV; no hubo IRAB por VSR ni por FLU. Se registraron 9 casos de IRAB por COVID-19: 2 bronquiolitis moderadas y 7 neumonías focales; con un adolescente fallecido por neumonía por COVID-19 con comorbilidades. En 2020, los casos presentaron mayor edad, más comorbilidades e internaciones previas en comparación con el 2019. La neumonía focal fue la presentación clínica predominante. Conclusión. En 2020, la tasa de hospitalización por IRAB se redujo significativamente en comparación con el año anterior, con ausencia de circulación de virus respiratorios estacionales en la población asistida en nuestro centro.