Role of Noroviruses in Sporadic Acute Gastroenteritis Cases from Children Attending a Large Referral Children's Hospital in Buenos Aires City, Argentina.

BACKGROUND: Noroviruses (NVs) are recognized as the leading cause of sporadic and epidemic acute gastroenteritis worldwide, in all age groups. Although there is increasing knowledge that NVs are responsible for many acute gastroenteritis outbreaks in Argentina, studies to estimate prevalence in sporadic cases are scarce. METHODS: A descriptive, observational and cross-sectional study was conducted with children under 5 years with acute gastroenteritis attending the outpatient department at the "Ricardo Gutiérrez" Children's Hospital (RGCH) in Buenos Aires City between June 2017 and June 2021. Sociodemographic, clinical and epidemiologic data were recorded. Stool samples were tested and genotyped for norovirus. Association between norovirus detection and demographic and clinical variables was assessed. RESULTS: A total of 350 children with acute diarrhea were included, of which stool samples were collected for 332 (94.9%). Norovirus was detected in 81 cases (24.4%). Vomiting and moderate/severe diarrhea were more frequent in norovirus-positive than norovirus-negative children. However, the presence of watery diarrhea and a history of rotavirus vaccination were significantly associated with norovirus etiology. GII and GII.4 were the most frequently detected genogroup and genotype, respectively. CONCLUSIONS: NVs were detected with high frequency, mostly in children between 6 months and 2 years old, reinforcing the hypothesis of a newly updated scenario of norovirus predominance over rotavirus. Watery diarrhea, complete vaccination against rotavirus and vomiting are 3 key parameters that should raise suspicion of possible norovirus gastroenteritis. Continuous and active norovirus surveillance in this age group is important because children represent a priority group for norovirus vaccine design and development.

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.

Burden of Respiratory Syncytial Virus Disease and Mortality Risk Factors in Argentina: 18 Years of Active Surveillance in a Children's Hospital.

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.

Enfermedad por Bordetella pertussis ¿Qué hacer ante una sospecha de coqueluche? / Bordetella pertussis disease. What to do when whooping cough is suspected

Coqueluche o tos convulsa es una enfermedad infecciosa, de presentación aguda, causada por la bacteria Bordetella pertussis. Hay evidencia de una alta carga de enfermedad en los países en desarrollo en los cuales sigue siendo una de las principales causas de muertes prevenibles por vacunación. La adecuada vigilancia epidemiológica, la detección precoz de casos, el manejo adecuado de brotes y el mantenimiento de altas coberturas de vacunación son los pilares de la prevención. El objetivo de este artículo es describir las normas vigentes para el manejo de los casos de Coqueluche y sus contactos

Pertussis or whooping cough is an infectious disease, of acute presentation, caused by the Bordetella pertussis bacterium. There is evidence of a high burden of disease in developing countries where it continues to be one of the leading causes of vaccine-preventable deaths. Adequate epidemiological surveillance, the early detection of cases, the proper management of outbreaks and the maintenance of high vaccination coverage are the pillars of prevention. The aim of this article is to describe the current guides for the management of cases of whooping cough and its contacts

Impacto de la vacunación para Rotavirus, ¿cuál es el rol de los Calicivirus humanos? / Impact of Rotavirus vaccination: what is the role of human Caliciviruses?

Las enfermedades infecciosas constituyen la segunda causa de mortalidad en los menores de 5 años. La diarrea aguda y la neumonía son las que generan la mayor carga de enfermedad. Argentina introdujo la vacunación sistemática contra rotavirus en el año 2015. El objetivo de este trabajo es describir el cambio epidemiológico de las diarreas agudas luego de la implementación de la vacuna rotavirus en Argentina, así como la eventual aparición de otros virus como nuevos agentes causales de esta patología y los desafíos para su diagnóstico. Para lograr el objetivo se realizó una revisión bibliográfica. En Argentina dos años después del inicio de la estrategia de vacunación con coberturas entre 61-75% se evidenció un descenso de 10% de las diarreas agudas globalmente y de 50% en las diarreas causadas por rotavirus. También se observó un desplazamiento de la estacionalidad en la ocurrencia de diarreas agudas de 10 semanas respecto a la etapa pre vacunación. A nivel mundial se ha descripto posterior a la introducción de la vacunación contra rotavirus una mayor relevancia de otros agentes (calicivirus humano) como causa de diarrea aguda, con un comportamiento diferencial en cuanto a la morbimortalidad, manejo clínico y diagnóstico. Se requiere un sistema de vigilancia continua e integrada para comprender la epidemiología y la evolución de estos agentes virales para ajustar medidas de prevención y control de la enfermedad

Infectious diseases are the second cause of mortality in children under 5 years of age. Acute diarrhea and pneumonia cause the greatest burden of disease. Argentina introduced routine rotavirus vaccination in 2015. The aim was to describe epidemiological changes in acute diarrhea after the implementation of rotavirus immunization in Argentina, as well as the possible appearance of other viruses as new causative agents and the challenges for its diagnosis. To achieve the objective, a bibliographic review was carried out. Argentina achieved coverage between 61-75% two years after the introduction in the national calendar. A decrease in acute diarrhea (10%) and diarrhea caused by rotavirus (50%) was observed. There was also change in the acute diarrhea seasonality, showing a delay in the occurrence of 10 weeks compared to the pre-vaccination stage. After the introduction of rotavirus vaccination a greater relevance of other agents (human calicivirus) has been described worldwide causing acute diarrhea, with a differential behavior in terms of morbidity, mortality, clinical management and diagnosis. A continuous and integrated surveillance system is required to understand the epidemiology and evolution of these viral agents to adjust measures for the prevention and control of the disease

Rol de los Calicivirus humanos en las diarreas agudas en niños menores de 5 años atendidos en forma ambulatoria en un hospital pediátrico de CABA / Role of human caliciviruses in acute diarrhea in children under 5 years of age treated as outpatients at a pediatric hospital in CABA

INTRODUCCIÓN La diarrea aguda es una de las principales causas de mortalidad infantil. Argentina introdujo la vacuna contra rotavirus en el año 2015. En varios países esta introducción en el calendario, modificó la distribución de los enteropatógenos y se ha descripto un descenso en la prevalencia de los rotavirus a expensas del aumento de los Norovirus (NoV). Este agente se está reportando como emergente y uno de los principales causantes de diarrea aguda en la comunidad. En Argentina existen pocas experiencias para estimar su prevalencia en los casos de diarrea aguda esporádicos en los menores de 5 años. El objetivo de este estudio es analizar el rol de los NoV en pacientes ambulatorios <5 años con diarrea y sus características epidemiológicas. OBJETIVOS Analizar el rol de los Calicivirus humanos en las diarreas agudas en <5 años atendidos en forma ambulatoria en un hospital pediátrico de la Ciudad de Buenos Aires. METODOLOGÍA Estudio observacional, transversal y descriptivo, se incluyeron niños atendidos en los consultorios externos del Hospital de Niños Dr. Ricardo Gutiérrez desde Mayo 2017 a Mayo 2018. Se llenaron fichas epidemiológicas para cada caso y las muestras se enviaron al Laboratorio de Gastroenteritis Virales INEI-ANLIS Dr. C. Malbrán para detección de calicivirus humano por RT-qPCR. Se confeccionó una base de datos para luego realizar el análisis. RESULTADOS Se incluyeron 136 pacientes y 125 muestras fueron procesadas. La mediana de edad fue de 20 meses (IQR: 12-31) y 59% fue de sexo masculino; el síntoma más frecuente fue fiebre y vómitos en un 70% y 55% respectivamente. Un 55% presentó diarrea acuosa seguida de un 43% con diarrea mucosanguinolenta. La severidad de la diarrea más frecuente, según la Escala de Vesikari, fue moderada en un 54% de los casos (n=73). El 74% de los pacientes estaba vacunado contra rotavirus y 89% con 2 dosis. De las 125 muestras procesadas 35 (27,8%) resultaron positivas para NoV. De ellas, 24 (68,6%) pertenecieron al genogrupo II y 11 (31,4%) al genogrupo I. El genotipo más frecuentemente detectado fue el GII.P16/GII.4. Comparando con los casos negativos para NoV, los casos positivos eran de menor edad (19 vs 22 meses; p<0,001) y se asociaron con alta prevalencia de vacunación contra rotavirus. No se encontró diferencia estadística significativa en sexo, clínica y severidad. DISCUSIÓN NoV fue detectado con alta frecuencia (28%) en nuestra población, principalmente en niños vacunados contra rotavirus. Con respecto a los casos de diarrea aguda en niños, es importante considerar el rol de los NoV como una etiología frecuente. Hacen falta más estudios de vigilancia con poblaciones más grandes para describir la prevalencia, las manifestaciones clínicas y los riesgos asociados con respecto a la diarrea por NoV en niños