Background The role of children in household transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains uncertain. Here, we describe the epidemiological and clinical characteristics of children with COVID-19 in Catalonia (Spain) and investigate the dynamics of household transmission. Methods Prospective, observational, multicenter study performed during summer and school periods (1 July-31 October, 2020), in which epidemiological and clinical features, and viral transmission dynamics were analyzed in COVID-19 patients <16 years. A pediatric index case was established when a child was the first individual infected within a household. Secondary cases were defined when another household member tested positive for SARS-CoV-2 before the child. The secondary attack rate (SAR) was calculated, and logistic regression was used to assess associations between transmission risk factors and SARS-CoV-2 infections. Results The study included 1040 COVID-19 patients <16 years. Almost half (47.2%) were asymptomatic, 10.8% had comorbidities, and 2.6% required hospitalization. No deaths were reported. Viral transmission was common among household members (62.3%). More than 70% (756/1040) of pediatric cases were secondary to an adult, whereas 7.7% (80/1040) were index cases. The SAR was significantly lower in households with COVID-19 pediatric index cases during the school period relative to summer (p=0.02), and when compared to adults (p=0.006). No individual or environmental risk factors associated with the SAR were identified. Conclusions Children are unlikely to cause household COVID-19 clusters or be major drivers of the pandemic even if attending school. Interventions aimed at children are expected to have a small impact on reducing SARS-CoV-2 transmission.

Background The objective of this study is to describe incidence and shifts of serotype and clonal distribution of invasive Streptococcus pneumoniae strains in four different age groups (<5 years, 5-17 years, 18-64 years and >65 years) during a period of intermediate PCV13 vaccination coverage (2011-2016) in Catalonia, Spain. Methods We included all pneumococcal strains systematically sent to the Catalan support laboratory for molecular surveillance of invasive pneumococcal disease (IPD) located at Hospital Sant Joan de Deu, Barcelona. Two study periods were considered: 2011-13, early PCV13 vaccination period (EVP) and 2014-2016, late vaccination period (LVP).

Vaccine failures occurring with 13-valent pneumococcal conjugate vaccine (PCV13) in 3 pediatric hospitals in Barcelona (2012-2013) are described. PCV13 vaccine failure was defined as the occurrence of an invasive pneumococcal infection in children properly vaccinated by PCV13. Among 84 patients with invasive pneumococcal infection, 32 had received at least one dose of PCV13. Seventeen of them had invasive pneumococcal infection produced by a PCV13 serotype. Among those, 9 patients were considered to have a PCV13 vaccine failure. Serotype 3 was isolated in 6 patients, serotype 19A in 2 and serotype 6B in 1.

Aim: The aim was to analyze the epidemiological, microbiological and clinical characteristics of patients with complicated pneumococcal pneumonia with pleural effusion (PE) or empyema. Method: Prospective study in three Catalan hospitals in persons aged <18 years diagnosed with complicated pneumonia with PE or empyema with isolation of Streptococcus pneumoniae in blood or pleural fluid by culture or real-time PCR between January 2012 and June 2016. Patients were divided into <2 years and 2-17 years age groups. Epidemiological, microbiological, and clinical data of patients were compared annually in both groups. PCV13 vaccination coverage increased from 48.2% in 2012 to 74.5% in 2015. Results:We included 143 patients. The incidence of pneumococcal pneumonia was 6.83 cases × 10 −5 persons/year in cases with PE or empyema and 2.09 cases × 10 −5 person-years in cases without (rate ratio [RR]: 3.27; 2.25-4.86; P < 0.001). Empyema was more frequent than PE (79.7% vs 20.3%, P < 0.005). Of 143 cases studied, 93 (65.0%, P < 0.001) were diagnosed by real-time-PCR, 43 (30.1%) by culture and RT-PCR and 7 (4.9%) by culture only. PCV13 serotypes were more frequent in complicated than in uncomplicated pneumonia (116/142, 81.7% vs 27/45, 60.0%; P = 0.003), especially serotype 1 (41/142, 28.9% vs 6/45, 13.3%, P : 0.036). From 2012 to 2015 there was a significant reduction in serotype 1 (16/43, 37.2% vs 3/27, 11.1%, P = 0.026), and a trend to an increase in non-PCV13 serotypes (6/43, 14% vs 9/27, 33.3%, P = 0.054). Conclusions:A directly proportional relationship was observed between the reduction in pneumonia complicated with PE or empyema and a significant

Aim The rapid spread of a novel human coronavirus SARS‐CoV‐2 led to drastic measures world‐wide. Most countries were forced to declare a national lockdown. We studied the effect of lockdown measures on the level of asthma control and maintenance treatment in children with recurrent wheezing and asthma during the first wave of COVID‐19 in Spain. Methods We analysed children with recurrent wheezing or asthma before and after the implementation of the lockdown, by using a questionnaire aimed to examine pre‐existing respiratory disorders, step treatment and level of asthma control before/after lockdown, COVID history and laboratory testing including IgG SARS‐CoV‐2. Results We enrolled 475 asthmatic and pre‐school wheezers (60.6% males), mean age 5.6 years. There were no differences in asthma treatment comparing both periods: 81.7% maintained the same treatment ( P = 0.103). According to child asthma‐control questionnaire, 87.7% remained well controlled during confinement. Nearly, a third of children (34.9%) needed reliever treatment, mainly in older children. Determination of IgG SARS‐CoV‐2 was performed in 233 children (49.1%) of whom 17 (7.3%) tested positive. Seven patients positive to IgG SARS‐CoV‐2 were assisted in the emergency department and two required hospital admission. Conclusions During COVID‐19 lockdown in Spain, most children with recurrent wheezing and asthma remained well controlled from their underlying disease and did not modify greatly their maintenance treatments. Unexpectedly, we also observed that those children who tested positive to SARS‐CoV‐2 IgG showed a significant increase in paediatric hospital admissions and attendances to urgent care settings.