A B S T R A C TIntroduction: Respiratory syncytial virus (RSV) is associated with substantial morbidity and mortality since it is a predominant viral agent causing respiratory tract infections in infants, young children and the elderly. Considering the availability of the RSV vaccines in the coming years, molecular understanding in RSV is necessary. Objective: The objective of the present study was to describe RSV epidemiology and genotype variability in Portugal during the 2014/15-2017/18 period. Material and methods: Epidemiological data and RSV-positive samples from patients with a respiratory infection were collected through the non-sentinel and sentinel influenza surveillance system (ISS). RSV detection, subtyping in A and B, and sequencing of the second hypervariable region (HVR2) of G gene were performed by molecular methods. Phylogenetic trees were generated using the Neighbor-Joining method and p-distance model on MEGA 7.0. Results: RSV prevalence varied between the sentinel (2.5%, 97/3891) and the non-sentinel ISS (20.7%, 3138/ 16779), being higher (P < 0.0001) among children aged < 5 years. Bronchiolitis (62.9%, 183/291) and influenza-like illness (24.6%, 14/57) were associated (P < 0.0001) with RSV laboratory confirmation among children aged < 6 months and adults ≥65 years, respectively. The HVR2 was sequenced for 562 samples. RSV-A (46.4%, 261/562) and RSV-B (53.6%, 301/562) strains clustered mainly to ON1 (89.2%, 233/261) and BA9

Introduction: Advances in molecular diagnosis have made it possible to detect previously unknown viral agents as causative agents of lower respiratory tract infections (LRTI). The frequency and relevance of viral coinfections is still debatable. Objective: Compare clinical presentation and severity between single virus infection and viral coinfection in children admitted for LRTI. Methods: A 3-year period observational study (2012---2015) included children younger than two years admitted for LRTI. Viral identification was performed using PCR technique for 16 viruses. Clinical data and use of health resources was gathered during hospital stay using a standard collection form and we compared single virus infection and viral coinfections. Results: The study included 524 samples (451 patients); 448 (85.5%) had at least one virus identified. Viral coinfections were found in 159 (35.5%). RSV and HRV were the most commonly identified virus; bronchiolitis and pneumonia the most frequent diagnosis. Patients with viral coinfections were older, attended day-care centers, had previous recurrent wheezing more frequently and were more symptomatic at admission. These patients did not have more duración de la estancia hospitalaria, de la necesidad de oxígeno, de UCI o soporte ventilatorio. Discusión: Nuestro estudio mostró una proporción significativa de coinfecciones virales en los niños pequeños ingresados con IVRI y confirma dados previos que muestran que la prescripción es más frecuente en las coinfecciones virales, sin asociación con peor resultado clínico.

Background: A significant proportion of pediatric-onset multiple sclerosis (POMS) patients do not respond to firstline disease-modifying therapies. Clinical trials showed that natalizumab is effective and safe in adults, but there are limited clinical trial data for children. Natalizumab is currently prescribed off-label for POMS. We aimed to characterize the effectiveness, safety and tolerability of natalizumab in all POMS cases treated in Portugal (from 2007 to 2018). Methods: Data from clinical records were retrospectively collected for all POMS cases treated with natalizumab in Portugal.Results: Twenty-one patients were included, 14 (67%) of which were female. The median age at POMS diagnosis was 13 years old. The median duration of treatment with natalizumab was 2 years and 3 months. Median Expanded Disability Status Scale score decreased from 1.5 to 1.0 after 24 months. The Annualized Relapse Rate decreased from 1.31 events/patient/year before treatment with natalizumab to 0 after 12 months of treatment and to 0.04 after 24 months. No gadolinium-enhancing lesions or new or enlarged T2 hyperintense lesions were observed in 8/8 patients (100%) after 12 months, and 4/5 (80%) after 24 months. There was one possible serious adverse event, which did not require dose adjustment. Five patients discontinued treatment due to positive anti-JCV (JC virus) antibody JC serostatus. Conclusion: Natalizumab may be an effective and safe disease-modifying therapy for POMS. Our results are in line with data published for the adult population, as well as with similar observational studies in pediatric populations in other regions.

Our study showed a significant proportion of viral coinfections in young infants admitted with LRTI and confirmed previous data showing that prescription was more frequent in inpatients with viral coinfections, without an association with worst clinical outcome.