Respiratory viral coinfections in pediatric patients in the primary care setting: a multicenter prospective study within the COPEDICAT network.

Acute respiratory viral infections pose a significant healthcare burden on the pediatric population globally, but data on the dissemination pattern in the community due to the COVID-19 pandemic are scarce. We conducted a two-year prospective multicenter study in Catalonia (Spain) that examined the prevalence and coinfection dynamics of respiratory viruses among 1276 pediatric patients from different age groups attending primary care. Coinfection analysis demonstrated complex patterns and revealed a coinfection rate of 23.8% for SARS-CoV-2, often in association with rhinovirus or influenza A. This study provides valuable data to understand post-pandemic viral interactions, which is imperative for public health interventions.

Molecular characterization and clinical impact of human bocavirus at a tertiary hospital in Barcelona (Catalonia, Spain) during the 2014-2017 seasons.

PURPOSE: The aim was to describe the prevalence, molecular epidemiology and clinical manifestations of human bocavirus (HBoV) in patients attended at a tertiary hospital in Barcelona, Spain. METHODS: From October 2014 to May 2017, respiratory specimens from paediatric patients were collected for respiratory viruses' laboratory-confirmation. Phylogenetic analyses from partial VP1 sequences were performed from all HBoV laboratory-confirmed specimens. Clinical features were retrospectively studied. RESULTS: 178/10271 cases were HBoV laboratory-confirmed. The median age was 1.53 (IQR 1.0-2.3). Co-detection was highly reported (136; 76%). All viruses belonged into HBoV1 genotype but one into HBoV2. Non-reported mutations were observed and two sites were suggestive to be under negative selection. 61% (109/178) cases had lower RTI (LRTI), of whom 84 had co-detections (77%) and 76 had comorbidities (70%). LRTI was the cause of hospitalization in 85 out of 109 cases (78%), and no differences were found regarding severity factors during hospitalization between co- and single-detections, except for median length of respiratory support, which was longer in cases with co-detections. CONCLUSIONS: Close monitoring of predominant HBoV1 showed a high similarity between viruses. The presence of comorbidities might explain the high prevalence of LRTI. Symptomatology in HBoV single-detected cases suggest that HBoV is a true pathogen.

Enterovirus D68 in Hospitalized Children, Barcelona, Spain, 2014-2021.

To determine molecular epidemiology and clinical features of enterovirus D68 (EV-D68) infections, we reviewed EV-D68-associated respiratory cases at a hospital in Barcelona, Spain, during 2014-2021. Respiratory samples were collected from hospitalized patients or outpatients with symptoms of acute respiratory tract infection or suggestive of enterovirus infection. Enterovirus detection was performed by real-time multiplex reverse transcription PCR and characterization by phylogenetic analysis of the partial viral protein 1 coding region sequences. From 184 patients with EV-D68 infection, circulating subclades were B3 (80%), D1 (17%), B2 (1%), and A (<1%); clade proportions shifted over time. EV-D68 was detected mostly in children (86%) and biennially (2016, 2018, 2021). In patients <16 years of age, the most common sign/symptom was lower respiratory tract infection, for which 11.8% required pediatric intensive care unit admission and 2.3% required invasive mechanical ventilation; neurologic complications developed in 1. The potential neurotropism indicates that enterovirus surveillance should be mandatory.

Genomic evolution of human respiratory syncytial virus during a decade (2013-2023): bridging the path to monoclonal antibody surveillance.

OBJECTIVES: This study investigated the prevalence, genetic diversity, and evolution of human respiratory syncytial virus (HRSV) in Barcelona from 2013 to 2023. METHODS: Respiratory specimens from patients with RTI suspicion at Hospital Universitari Vall d'Hebron were collected from October 2013 to May 2023 for laboratory-confirmation of respiratory viruses. Next-generation sequencing was performed in randomly-selected samples with Illumina technology. Phylogenetic analyses of whole genome sequences were performed with BEAST v1.10.4. Signals of selection and evolutionary pressures were inferred by population dynamics and evolutionary analyses. Mutations in major surface proteins were genetic and structurally characterised, emphasizing those within antigenic epitopes. RESULTS: Analyzing 139,625 samples, 5.3% were HRSV-positive (3008 HRSV-A, 3882 HRSV-B, 56 HRSV-A and -B, and 495 unsubtyped HRSV), with a higher prevalence observed in the paediatric population. Pandemic-related shifts in seasonal patterns returned to normal in 2022-2023. A total of 198 whole-genome sequences were obtained for HRSV-A (6.6% of the HRSV-A positive samples) belonging to GA2.3.5 lineage. For HRSV-B, 167 samples were sequenced (4.3% of the HRSV-B positive samples), belonging to GB5.0.2, GB5.0.4a and GB5.0.5a. HRSV-B exhibited a higher evolution rate. Post-SARS-CoV-2 pandemic, both subtypes showed increased evolutionary rates and decreased effective population size initially, followed by a sharp increase. Analyses indicated negative selective pressure on HRSV. Mutations in antigenic epitopes, including S276N and M274I in palivizumab-targeted site II, and I206M, Q209R, and S211N in nirsevimab-targeted site Ø, were identified. DISCUSSION: Particularly in the context of the large-scale use in 2023-2024 season of nirsevimab, continuous epidemiological and genomic surveillance is crucial.