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Initially, the impact of SARS-CoV-2 infection on children was unknown. Standard COVID-19 diagnosis is confirmed using real-time qPCR. Cycle threshold (Ct) values of RT-qPCR are inversely proportional to viral load and the test indirectly quantifies viral RNA copy numbers. The objective of this study was to determine the correlation between epidemiology, clinical characteristics, severity of confirmed COVID-19 cases, and Ct values.An observational, analytical, cross-sectional study. All children with COVID-19 under 18 years old admitted to the Ricardo Gutiérrez Children's Hospital between March 1, 2020, and February 28, 2021, were included. SARS-CoV-2 infection was confirmed using RT-qPCR.Median age of patients was 7 years. Ct values were estimated in 419 cases, median Ct value was 23.5 [interquartile range (IQR): 18.9-30.9]. Levels were significantly lower in symptomatic than asymptomatic patients (Ct: 22.1; IQR: 18.4-22.1), in children2 years of age (Ct: 20.6; IQR: 17.3-27.3) and when sample collection was4 days after symptom onset (Ct: 21.1; IQR: 18.1-27.5). In children2 years of age, Ct values were significantly lower in symptomatic (Ct: 22.6; IQR: 18.7-29.3) than asymptomatic (Ct: 31.2; IQR: 24.5-33.3) patients.Children younger than 2 years with COVID-19 have lower values of Ct-as a proxy for higher viral load-than older children. Symptomatic children over 2 years of age had lower Ct values compared with asymptomatic children.

Globally, the human respiratory syncytial virus (RSV) is one of the major causes of lower respiratory tract infections (LRTIs) in children. The scarcity of complete genome data limits our understanding of RSV spatiotemporal distribution, evolution, and viral variant emergence. Nasopharyngeal samples collected from hospitalized pediatric patients from Buenos Aires tested positive for RSV LRTI during four consecutive outbreaks (2014–2017) were randomly subsampled for RSV complete genome sequencing. Phylodynamic studies and viral population characterization of genomic variability, diversity, and migration of viruses to and from Argentina during the study period were performed. Our sequencing effort resulted in one of the largest collections of RSV genomes from a given location (141 RSV-A and 135 RSV-B) published so far. RSV-B was dominant during the 2014–2016 outbreaks (60 per cent of cases) but was abruptly replaced by RSV-A in 2017, with RSV-A accounting for 90 per cent of sequenced samples. A significant decrease in RSV genomic diversity—represented by both a reduction in genetic lineages detected and the predominance of viral variants defined by signature amino acids—was observed in Buenos Aires in 2016, the year prior to the RSV subgroup predominance replacement. Multiple introductions to Buenos Aires were detected, some with persistent detection over seasons, and also, RSV was observed to migrate from Buenos Aires to other countries. Our results suggest that the decrease in viral diversity may have allowed the dramatic predominance switch from RSV-B to RSV-A in 2017. The immune pressure generated against circulating viruses with limited diversity during a given outbreak may have created a fertile ground for an antigenically divergent RSV variant to be introduced and successfully spread in the subsequent outbreak. Overall, our RSV genomic analysis of intra- and inter-outbreak diversity provides an opportunity to better understand the epochal evolutionary dynamics of RSV.

Most countries in Latin America have already reported thousands of confirmed cases and vulnerable populations are the most affected by the coronavirus disease 2019 (COVID-19) pandemic. Preventive measures such as hygiene, social distancing, and isolation, essential to stop the spread of coronavirus, are difficult to accomplish for vulnerable populations due to their living conditions. Seroepidemiological surveys are assets to measure the transmission for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Until July 1st, the incidence rate of SARS-CoV-2 infection in Barrio Padre Mugica, one of the largest slums in Buenos Aires City, was 5.9%. This study aimed to establish the prevalence of SARS-CoV-2 antibodies immunoglobulin G (IgG) immediately after the outbreak, and to identify neighbourhood, household and individual factors associated with seroconversion. The prevalence based on IgG was 53.4% (95% CI 52.8% to 54.1%). For each polymerase chain reaction (RT-qPCR) confirmed case, nine people tested IgG positive, indicating a high rate of undetected (probably asymptomatic) infections. Hence, the high rate of undiagnosed people suggests that clinical criteria and epidemiological nexus should be considered. The high seroprevalence observed in the context of an intense epidemic in a vulnerable area might serve as a reference to other countries. This study contributes to future decision making by understanding population immunity against SARS-CoV2 and its relation to living conditions and foccus that comprehensive biosocial, household-level interventions are needed.Muchos países de América Latina han informado miles de casos confirmados y las poblaciones vulnerables son las más afectadas por la pandemia de la enfermedad por coronavirus 2019 (COVID-19). Las medidas preventivas como la higiene, el distanciamiento social y el aislamiento, fundamentales para frenar la propagación del coronavirus, son difíciles de lograr en estas poblaciones debido a sus condiciones de vida. Los estudios seroepidemiológicos son de gran utilidad para medir la transmisión del síndrome respiratorio agudo severo coronavirus 2 (SARS-CoV-2). Hasta el 1 de julio, la tasa de incidencia de la infección por SARS-CoV-2 en el Barrio Padre Mugica, uno de los barrios marginales más grandes de la ciudad de Buenos Aires, era del 5.9%. Este estudio tuvo como objetivo estimar la prevalencia de anticuerpos inmunoglobulina G (IgG) para SARS-CoV-2 inmediatamente después del brote, e identificar factores del barrio, hogar e individuales asociados con la seroconversión. La prevalencia basada en IgG fue del 53.4% (IC del 95%: 52.8% a 54.1%). Para cada caso confirmado por reacción en cadena de la polimerasa (RT-qPCR), nueve personas dieron positivo en IgG, lo que indica una alta tasa de infecciones no detectadas y probablemente asintomáticas. La alta tasa de personas no diagnosticadas sugiere que se deben considerar los criterios clínicos y el nexo epidemiológico. La alta seroprevalencia observada en el contexto de una intensa epidemia en una zona vulnerable podría servir de referencia a otros países. Este estudio contribuye a la toma de decisiones futuras al comprender la inmunidad de la población contra el SARS-CoV2 en su relación con las condiciones de vida y por su enfoque en la necesidad de intervenciones integrales a nivel del hogar.

Dystrophic epidermolysis bullosa (DEB) is a clinically heterogeneous heritable skin disorder, characterized by blistering of the skin and mucous membranes following minor trauma. Dominant (DDEB) and recessive (RDEB) forms are caused by pathogenic variants in COL7A1 gene. Argentina's population has a heterogeneous genetic background, and little is known about the molecular basis of DEB in our country or in native South American populations. In this study, we present the prevalence and geographical distribution of pathogenic variants found in 181 patients from 136 unrelated families (31 DDEB and 105 RDEB). We detected 95 different variants, 59 of them were previously reported in the literature and 36 were novel, nine of which were detected in more than one family. The most prevalent pathogenic variants were identified in exon 73 in DDEB patients and in exon 3 in RDEB patients. We also report a new phenotype-genotype correlation found in 10 unrelated families presenting mild blistering and severe mucosal involvement. Molecular studies in populations with an unexplored genetic background like ours revealed a diversity of pathogenic variants, and we hope that these findings will contribute to the definition of targets for new gene therapies.

RESUMEN 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 en2020). 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.

Rapid antigen tests (RAgTs) for SARS-CoV-2 are considered adequate for diagnosis at the point of care. Our objective was to establish the agreement between reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and RAgTs in the pediatric population.All patients aged 1 month to 17 years and 11 months seen at the Emergency Fever Unit of a children's hospital between 6-11-2021 and 10-3-2021 were recruited. The Panbio COVID-19 Ag® test (Abbott Diagnostic) was compared to the reference method RT-qPCR (as per the protocol suggested by the United States Centers for Disease Control and Prevention).A total of 6491 patients were included. The prevalence of COVID-19 was 2.8%. Symptoms were observed in 92.1%. Sensitivity, specificity, and the kappa index of agreement for the RAgT were 71.0%, 99.9%, and 0.813, respectively. The kappa index and the RAgT sensitivity were significantly higher in the group aged 13-17 years (0.89 and 82.4%, respectively) compared to the groups aged 0-5 and 6-12 years. This may be due to the lower viral load observed in patients younger than 12 years.Although RAgTs shorten the time to result and improve the isolation strategy for COVID-19 patients, their sensitivity in children younger than 12 years or asymptomatic children is not within the recommended ranges, especially during periods of low disease prevalence.Introducción. Los inmunoensayos de detección rápida de antígenos (TRA) del SARS-CoV-2, son considerados adecuados para el diagnóstico en el punto de atención. El objetivo fue conocer la concordancia entre la reacción en cadena de la polimerasa en tiempo real con transcriptasa inversa (RT-qPCR, por su sigla en inglés) y los TRA en población pediátrica. Población y métodos. Se reclutaron todos los pacientes entre 1 mes y 17 años 11 meses de edad atendidos en la Unidad Febril de Urgencia de un hospital pediátrico entre el 11 de junio y el 3 de octubre de 2021. Se utilizó el TRA Panbio COVID-19 Ag® (Abbott Diagnostic) y, como método de referencia, la RT-qPCR (según el protocolo de los Centros para el Control y la Prevención de Enfermedades). Resultados. Se incluyeron 6491 pacientes. La prevalencia de COVID-19 fue del 2,8 %. El 92,1 % de los sujetos presentaron síntomas. La sensibilidad, la especificidad y el índice kappa de concordancia para el TRA fueron del 71,0 %, 99,9 % y 0,813, respectivamente. El índice kappa y la sensibilidad del TRA fueron significativamente mayores en el grupo de 13 a 17 años (0,89 y 82,4 %, respectivamente) cuando se los comparó con los grupos de 0 a 5 y de 6 a 12 años. Esto podría deberse a la menor carga viral observada en los pacientes menores de 12 años. Conclusión. Si bien los TRA permiten acortar el tiempo de obtención de los resultados y mejorar la estrategia de aislamiento de pacientes con COVID-19, la sensibilidad en niños menores de 12 años o asintomáticos no se encontraría dentro de los rangos recomendados, sobre todo en períodos de baja prevalencia de la enfermedad.

The community mitigation measures taken because of the COVID-19 pandemic had side effects on the circulation of the most frequent respiratory viruses during 2020. In the case of respiratory syncytial virus (RSV), an important paediatric pathogen, a decrease in the number of cases and delayed outbreaks was previously described.The genetic characteristics of the RSV circulating strains in paediatric patients in Buenos Aires, Argentina before and during the COVID-19 pandemic were studied. RSV (+) samples taken from hospitalised patients with respiratory tract infections (2018- 2021) were analysed through G gene sequencing and evolutionary analyses.No RSV hospitalised paediatric patients were registered in Buenos Aires during 2020; however, RSV reemerged in 2021 with a lower number of cases and a delayed outbreak, peaking in July-August. A total of 147 G gene sequences were analysed. RSV-B (N = 85) predominated during 2018 and 2021 whereas in 2019 RSV-A were more prevalent (N = 62). All RSV-A sequences were ON1-like strains, and all RSV-B were BA-like. Phylogenetic analyses showed that the same genetic lineages circulated before and after 2020, but RSVs from 2021 corresponded to new viral introductions rather than cryptic circulation of the previous genetic clusters in Buenos Aires during 2020.Following the reopening of borders, the reemergence of RSV in Argentina brought new viral introductions from other countries. Therefore, it is important to continue a deep global molecular surveillance to characterise RSV strains in post-pandemic circulation with an impact in future vaccine implementation.

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.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.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.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.

BACKGROUND: Human respiratory syncytial virus (RSV) is classified into antigenic subgroups A and B. Thirteen genotypes have been defined for RSV-A and 20 for RSV-B, without any consensus on genotype definition. METHODS: We evaluated clustering of RSV sequences published in GenBank until February 2018 to define genotypes by using maximum likelihood and Bayesian phylogenetic analyses and average p-distances. RESULTS: We compared the patterns of sequence clustering of complete genomes; the three surface glycoproteins genes (SH, G, and F, single and concatenated); the ectodomain and the 2nd hypervariable region of G gene. Although complete genome analysis achieved the best resolution, the F, G, and G-ectodomain phylogenies showed similar topologies with statistical support comparable to complete genome. Based on the widespread geographic representation and large number of available G-ectodomain sequences, this region was chosen as the minimum region suitable for RSV genotyping. A genotype was defined as a monophyletic cluster of sequences with high statistical support (≥80% bootstrap and ≥0.8 posterior probability), with an intragenotype p-distance ≤0.03 for both subgroups and an intergenotype p-distance ≥0.09 for RSV-A and ≥0.05 for RSV-B. In this work, the number of genotypes was reduced from 13 to three for RSV-A (GA1-GA3) and from 20 to seven for RSV-B (GB1-GB7). Within these, two additional levels of classification were defined: subgenotypes and lineages. Signature amino acid substitutions to complement this classification were also identified. CONCLUSIONS: We propose an objective protocol for RSV genotyping suitable for adoption as an international standard to support the global expansion of RSV molecular surveillance. ispartof: INFLUENZA AND OTHER RESPIRATORY VIRUSES vol:14 issue:3 pages:274-285 ispartof: location:England status: published

Background: Respiratory syncytial virus is the leading cause of acute lower respiratory infection in children. We aimed to describe the clinical-epidemiologic pattern and risk factors for mortality associated with RSV infection. Methods: This is a prospective, cross-sectional study of acute lower respiratory infection in children admitted to the Children’s Hospital during 2000 to 2017. Viral diagnosis was made by fluorescent antibody techniques or real-time-polymerase chain reaction. We compared clinical-epidemiologic characteristics of RSV infection in nonfatal versus fatal cases. Multiple logistic regression was used to identify independent predictors of mortality. Results: Of 15,451 patients with acute lower respiratory infection, 13,033 were tested for respiratory viruses and 5831 (45%) were positive: RSV 81.3% (4738), influenza 7.6% (440), parainfluenza 6.9% (402) and adenovirus 4.3% (251). RSV had a seasonal epidemic pattern coinciding with months of lowest average temperature. RSV cases show a case fatality rate of 1.7% (82/4687). Fatal cases had a higher proportion of prematurity (P < 0.01), perinatal respiratory history (P < 0.01), malnourishment (P < 0.01), congenital heart disease (P < 0.01), chronic neurologic disease (P < 0.01) and pneumonia at clinical presentation (P = 0.014). No significant difference between genders was observed. Most deaths occurred among children who had complications: respiratory distress (80.5%), nosocomial infections (45.7%), sepsis (31.7%) and atelectasis (13.4%). Independent predictors of RSV mortality were moderate-to-severe malnourishment, odds ratio (OR): 3.69 [95% confidence interval (CI): 1.98–6.87; P < 0.0001]; chronic neurologic disease, OR: 4.14 (95% CI: 2.12–8.08; P < 0.0001); congenital heart disease, OR: 4.18 (95% CI: 2.39–7.32; P< 0.0001); and the age less than 6 months, OR: 1.99 (95% CI: 1.24–3.18; P = 0.004). Conclusions: RSV showed an epidemic pattern affecting mostly young children. Malnourishment, chronic neurologic disease, congenital heart disease and the age less than 6 months were the independent risk factors for RSV mortality. Fil: Gentile, Angela. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; Argentina Fil: Lucion, Maria Florencia. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; Argentina Fil: Juarez, Maria del Valle. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; Argentina Fil: Areso, María Soledad. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; Argentina Fil: Bakir, Julia. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; Argentina Fil: Viegas, Mariana. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez". Laboratorio de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Mistchenko, Alicia Susana. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez". Laboratorio de Virología; Argentina

Se presenta el caso de un niño de 5 años sin antecedentes de enfermedad, que se internó en terapia intensiva por convulsiones tónico-clónicas focalizadas en la cara y en el hemicuerpo derecho, con documentación de temperatura axilar de 37,4°C. Se descartó la presencia de gérmenes comunes y la etiología viral a través de estudios de muestras de líquido cefalorraquídeo (LCR). Se sospechó la presencia de Mycoplasma pneumoniae por comprobarse inmunofluorescencia positiva en suero para anticuerpos de clase IgM. El diagnóstico se confirmó mediante la detección del ADN de dicho patógeno sobre la biopsia cerebral efectuada por el método de la reacción en cadena de la polimerasa (PCR) y una histología compatible con encefalomielitis aguda diseminada. El paciente recibió tratamiento con claritromicina y su evolución fue favorable. Al menos dentro de nuestros conocimientos, este es el primer caso en el que se detectó ADN de M. pneumoniae en una biopsia cerebral por el método de PCR. We present here the case of a previously healthy 5 year-old boy hospitalized in an intensive care unit due to tonic-clonic seizures focused on the face and right side of the body, and axillary temperature of 37.4 °C. Common bacterial and viral etiology was ruled out through studies of cerebrospinal fluid (CSF) samples. Mycoplasma pneumoniae was suspected by a positive immunofluorescence serum test for IgM class antibodies. Finally, with a brain biopsy, M. pneumoniae was confirmed by polymerase chain reaction (PCR) and acute disseminated encephalomyelitis by pathological anatomy. The patient was treated with clarithromycin and had an uneventful evolution. At least to our knowledge, this is the first case in which M. pneumoniae DNA was detected by PCR in a brain biopsy.

Molecular surveillance of SARS-CoV-2 variants was performed on a total of 2,406 samples from the capital city and nine provinces of Argentina, during 30 epidemiological weeks (EW) that covered the end of the first wave and the beginning of the ongoing second wave of the COVID-19 pandemic in the country (EW 44/2020 to EW 20/2021). The surveillance strategy was mainly based on Sanger sequencing of a Spike coding region that allows the simultaneous identification of signature mutations associated with worldwide circulating variants. In addition, whole SARS-CoV-2 genome sequences were obtained from 456 samples. The main variants found were Gamma, Lambda and Alpha, and to a lesser extent, Zeta and Epsilon. Whereas Gamma dominated in different regions of the country, both Gamma and Lambda prevailed in the most populated area, the metropolitan region of Buenos Aires (MABA), although showing a heterogeneous distribution along this region. This cost-effective surveillance protocol allowed for a rapid response in a limited access to resources scenario, added information on the expansion of the Lambda variant in South America and contributed to the implementation of public health measures to control the disease spread in Argentina.

Dengue is a public health problem worldwide. It was originally confined to tropical and subtropical areas, but it is now present in other regions, such as Argentina. Epidemic outbreaks have been observed in the City of Buenos Aires since 2008, with few reports in children.To analyze and compare the clinical, epidemiological, laboratory, and evolutionary characteristics of the latest 2 dengue outbreaks outside the endemic area.Time-series study. Patients under 18 years of age with probable or confirmed dengue and evaluated in a children's hospital of the City of Buenos Aires during the periods 2015-2016 and 2019-2020 were included.A total of 239 patients were included; 29 (12%) had a history of travel. Their median age was 132 months (interquartile range: 102- 156). All had a fever. Other symptoms included headache in 170 (71%), myalgia in 129 (54%), and rash in 122 (51%). Forty patients (17%) had comorbidities. Warning signs were observed in 79 patients (33%); 14 (6%) developed severe dengue; 115 (45%) were hospitalized; none died. DENV-1 was the most common serotype. A history of travel and hospitalization prevailed in the first period; severe dengue and prior infection, in the second period.No patient died due to dengue in either study period. Statistically significant differences were observed in the frequency of hospitalization; a history of travel was more common in the 2015-2016 period and severe dengue, in the 2019-2020 period.Introducción. El dengue es un problema de salud pública a nivel mundial. Confinado en sus orígenes a las zonas tropicales y subtropicales, en la actualidad se presenta en otras regiones como Argentina. Desde el año 2008 se presenta con brotes epidémicos en la Ciudad Autónoma de Buenos Aires, con escasos reportes en niños.Analizar y comparar las características clínicas, epidemiológicas, de laboratorio y evolutivas de los dos últimos brotes de dengue fuera del área endémica. Población y métodos. Estudio de series temporales. Se incluyeron pacientes menores de 18 años con dengue probable o confirmado, evaluados en un hospital pediátrico de la Ciudad de Buenos Aires durante los períodos 2015-2016 y 2019-2020.Se incluyeron 239 pacientes, 29 (12 %) con antecedente de viaje. La mediana de edad fue de 132 meses (rango intercuartílico: 102-156). Todos tuvieron fiebre. Otros síntomas fueron: cefalea en 170 (71 %), mialgias en 129 (54 %) y exantema en 122 (51 %). Cuarenta pacientes (17 %) tenían comorbilidades. Presentaron signos de alarma 79 pacientes (33 %) y 14 (6 %) tenían dengue grave. Requirieron internación 115 pacientes (45 %) y ninguno falleció. El serotipo DENV-1 fue el más frecuente. El antecedente de viaje y la necesidad de internación predominaron en el primer período; el dengue grave y la infección previa, en el segundo.Ningún paciente falleció de dengue en los períodos estudiados. Se observaron diferencias estadísticamente significativas en la frecuencia de internación; el antecedente de viaje fue más frecuente en el período 2015-2016 y el dengue grave, en el 2019-2020.

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.Observational, retrospective, and descriptive study of patients hospitalized due to ALRTI comparing 2019 and 2020.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.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.

Background: In December 2020, Sputnik V was the first vaccine incorporated to the National Strategic COVID-19 Immunization Plan in Argentina. An interim phase three analysis carried out in the Russian Federation had shown 98% of Sputnik V vaccinees developed specific antibodies to SARS-CoV-2. To date, data on immunogenicity in Argentina are scarce. The objective of this study was to assess the immune response following vaccination with two doses of Sputnik V in health-care workers (HCW) at a Children’s Hospital. Methods: A prospective, cohort study in HCWs immunized with two doses of Sputnik V between February and May 2021. The following variables were assessed: age, gender, profession, risk factors for severe COVID-19 or mortality, immunosuppressive therapy and history of COVID-19 infection. Blood samples were drawn on the day of the first dose and 21-40 days after the second. Anti-Spike IgG was measured using an ELISA assay and antibody levels classified into five semi-quantitative categories: non-reactive, < 1/100, ≥1/100-< 1/1000, ≥1/1000

Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infection (ALRTI) in pediatrics. Preterm infants are at a higher risk for complications. We aimed to describe and compare the clinical and epidemiological characteristics associated with ALRTI due to RSV in preterm and term infants and to establish the predictors of fatality among preterm infants.Prospective, cross-sectional study of patients admitted due to ALRTI in the 2000-2018 period. Viral diagnosis was done by indirect immunofluorescence or reverse transcription polymerase chain reaction in nasopharyngeal aspirates. Clinical and epidemiological characteristics were recorded. A multiple logistic regression model established the predictors of fatality among preterm infants.A total of 16 018 ALRTI cases were included; 13 545 (84.6 %) were tested; 6047 (45 %) were positive; RSV was prevalent in 81.1 % (4907), with a seasonal epidemic pattern; 14 % (686) were preterm infants. Comorbidities, perinatal respiratory history, congenital heart disease, malnutrition, chronic respiratory disease, bronchopulmonary dysplasia, prior hospitalization due to ALRTI, and chronic neurological disease (p0.001) were more common among preterm infants; they required more intensive care and a longer length of stay, and had a higher fatality rate (p0.01). Congenital heart disease was an independent predictor of fatality due to RSV among preterm infants (OR: 3.67 [1.25-10.8], p = 0.01).RSV showed an epidemic pattern and affected more preterm infants with certain comorbidities, with a higher morbidity and mortality, compared to term infants. RSV fatality among preterm infants was associated with congenital heart disease.Introducción. El virus sincicial respiratorio (VSR) es el principal agente causal de la infección respiratoria aguda baja (IRAB) en pediatría. Los niños prematuros tienen mayor riesgo de complicaciones asociadas con esta infección. Los objetivos fueron describir y comparar las características clínicas y epidemiológicas asociadas a IRAB por VSR en niños/as nacidos pretérmino y a término, y establecer predictores de letalidad en los prematuros. Métodos. Estudio prospectivo, transversal, de pacientes ingresados por IRAB, en el período 2000-2018. El diagnóstico virológico se realizó mediante inmunofluorescencia indirecta o reacción en cadena de la polimerasa con transcriptasa inversa de aspirados nasofaríngeos. Se registraron las características clínicoepidemiológicas. Se desarrolló un modelo de regresión logística múltiple para establecer los predictores de letalidad en prematuros. Resultados. Se incluyeron 16 018 casos de IRAB; 13 545 (el 84,6 %) fueron estudiados; 6047 (el 45 %) positivos; VSR predominó en el 81,1 % (4907); mostró un patrón epidémico estacional; el 14 % (686) fueron prematuros. Los prematuros mostraron mayor frecuencia de comorbilidades, antecedentes respiratorios perinatales, cardiopatía congénita, desnutrición, enfermedad respiratoria crónica, displasia broncopulmonar, hospitalización previa por IRAB y enfermedad neurológica crónica (p0,001); requirieron más cuidados intensivos, mayor tiempo de internación y mayor tasa de letalidad (p0,01). La cardiopatía congénita fue predictor independiente de letalidad por VSR en prematuros [OR 3,67 (1,25-10,8), p = 0,01]. Conclusión. VSR mostró un patrón epidémico, afectó a prematuros con ciertas comorbilidades con mayor morbimortalidad que los de término. La letalidad por VSR en prematuros se asoció con la cardiopatía congénita.

BackgroundBy July 1st, the incidence rate of RT-qPCR SARS-CoV-2 infection was 5.9% in Barrio Padre Mugica, one of the largest slums in Buenos Aires City. This study aimed to establish the seroprevalence of SARS-CoV-2 three months after the first case was reported.MethodsBetween June 10th and July 1st, a cross-sectional design was carried out on people over 14 years old, selected from a probabilistic sample of households. A finger prick sample was tested by ELISA to detect IgG-class antibodies against SARS-CoV-2. Multilevel model was applied to understand sector, household and individual conditions associated with seroconvert.ResultsPrevalence based on IgG was 53.4% (95%IC 52.8% to 54.1%). Among the IgG positive cases, 15% reported having compatible symptoms at some point in the past two months. There is evidence of within-household clustering effect (rho=0.52; 95% IC 0.36-0.67); living with a PCR-confirmed case doubled the chance of being SARS-CoV2 IgG positive (OR 2.13; 95% IC 1.17-3.85). The highest risk of infection was found in one of the most deprived areas of the slum, the “Bajo autopista” sector.DiscussionHigh seroprevalence is shown, for each symptomatic RT-qPCR-confirmed diagnosis, 9 people were IgG positive, indicating a high rate of undetected (probable asymptomatic) infections. Given that transmission among family members is a leading driver of the disease’s spread, it is unsurprising that crowded housing situations in slums are directly associated with higher risk of infection and consequently high seroprevalence levels.This study contributes to the understanding of population immunity against SARS-CoV2, its relation to living conditions and viral spread, for future decision making.

Acute lower respiratory tract infection (ALRTI) caused by adenovirus is a major cause of morbidity and mortality in children.To describe the clinical and epidemiological pattern and associated factors in hospitalized children.Cross-sectional study in children admitted due to ALRTI to Hospital de Niños "Ricardo Gutiérrez," in the Autonomous City of Buenos Aires, between 2000 and 2018. Viral diagnosis was done by indirect immunofluorescence in nasopharyngeal secretions. The clinical and epidemiological characteristics of adenovirus infection were compared to other respiratory viruses (respiratory syncytial virus, influenza, and parainfluenza). A multiple logistic regression was done to identify independent predictors of infection.Out of 16 018 patients with ALRTI, 13 545 were tested for respiratory viruses; 6047 (45 %) had a positive result. Adenovirus was the least common agent (4.4 % [265] of cases); it tended towards a reduction over the study period (peak in 2003) and circulated throughout the year (peak in July). In total, 63.8 % of patients were males; median age: 11 months (interquartile range: 6-20). The most common clinical presentation was pneumonia (63 %). Prior admissions due to respiratory conditions were seen in 50 %; 15.6 % were readmissions; 58.3 % had comorbidities. Ventilatory support was required by 19.2 % and complications were recorded in 44 %. The fatality rate was 7.7 %. Adenovirus infection was associated with age ≥ 12 months, male sex, clinical presentation of pneumonia, prior admissions due to respiratory conditions, and readmissions.Adenoviruses were less common than other respiratory viruses, although their morbidity and mortality were important.Introducción. La infección respiratoria aguda baja por adenovirus es una importante causa de morbimortalidad en niños. Objetivos: Describir el patrón clínicoepidemiológico y los factores asociados en niños hospitalizados. Métodos. Estudio transversal en niños ingresados por infección respiratoria aguda baja al Hospital de Niños Ricardo Gutiérrez, Buenos Aires, en 2000-2018. El diagnóstico viral se realizó mediante inmunofluorescencia indirecta en secreciones nasofaríngeas. Se compararon características clínico-epidemiológicas de infección por adenovirus con otros virus respiratorios (virus sincicial respiratorio, influenza y parainfluenza). Se utilizó regresión logística múltiple para identificar predictores independientes de infección. Resultados. De 16018 pacientes con infección respiratoria aguda baja, 13545 fueron testeados para virus respiratorios y 6047 (el 45 %) fueron positivos. Adenovirus fue el agente menos frecuente [el 4,4 % (265) de los casos]; presentó una tendencia en descenso durante todo el período estudiado (pico en 2003) y circuló durante todo el año (pico en julio). El 63,8 % eran varones; mediana de edad: 11 meses (rango intercuartílico: 6-20). La presentación clínica más frecuente fue neumonía (el 63 %). El 50 % tenía internaciones previas por causa respiratoria; el 15,6 % eran reingresos; el 58,3 % tenía comorbilidades. El 19,2 % requirió asistencia ventilatoria; el 44 % registró complicaciones. La letalidad fue del 7,7 %. La infección por adenovirus se asoció a edad ≥ 12 meses, sexo masculino, presentación clínica de neumonía, internaciones previas por causas respiratorias y reinternaciones. Conclusiones. Los adenovirus fueron detectados con menor frecuencia que los otros virus respiratorios, aunque presentaron un importante perfil de morbimortalidad.