Mycoplasma pneumoniae (MP) is one of the main causes of both upper and lower respiratory infections in school-aged children, accounting for up to 40% of community-acquired pneumonia. Younger children are also affected, and extrapulmonary manifestations have been recently reported in the pediatric population. We carried out a retrospective analysis of MP-positive patients admitted to the Pediatric Emergency Unit of S. Orsola Malpighi University Hospital in Bologna, the largest tertiary pediatric referral center in the Emilia–Romagna region, Northern Italy, between 2012 and 2020. We identified 145 patients with MP infection (82 males and 63 females), 27% of which were younger than 2 years; the median age was 5 years (interquartile range 1–9). The clinical presentation partially differed between age groups. School-aged children were more likely to have a chest X-ray-confirmed pneumonia (p = 0.013), while younger children required oxygen therapy more often (p = 0.048). Seventy-four children (51%) showed extrapulmonary manifestations, mainly gastrointestinal (30%) and dermatological (14%). Neurological symptoms were more frequent in children older than 6 years (p = 0.006). The rate of other extrapulmonary manifestations did not differ significantly between age groups. This study shows that MP infection is a frequent cause of pediatric hospitalization, including of children younger than 2 years. Clinicians should be aware of the variable clinical expressions of MP, including extrapulmonary manifestations, to achieve a correct diagnosis and determine appropriate treatment.

The aim of this study was to understand the epidemiology, disease severity, and microbiology of bronchiolitis in Italy during the 2021–2022 cold season, outside of lockdowns. Before COVID-19, the usual bronchiolitis season in Italy would begin in November and end in April, peaking in February. We performed a prospective observational study in four referral pediatric centers located in different geographical areas in Italy (two in the north, one in the center and one in the south). From 1 July 2021 to 31 January 2022, we collected all new clinical diagnoses of bronchiolitis in children younger than two years of age recording demographic, clinical and microbiological data. A total of 657 children with a clinical diagnosis of bronchiolitis were enrolled; 56% children were admitted and 5.9% required PICU admission. The first cases were detected during the summer, peaking in November 2021 and declining into December 2021 with only a few cases detected in January 2022. RSV was the commonest etiological agent, while SARS-CoV-2 was rarely detected and only since the end of December 2021. Disease severity was similar in children with RSV vs. non-RSV bronchiolitis, and in those with a single infectious agent detected compared with children with co-infections. The 2021–2022 bronchiolitis season in Italy started and peaked earlier than the usual pre-pandemic seasons, but had a shorter duration. Importantly, the current bronchiolitis season was not more severe when data were compared with Italian published data, and SARS-CoV-2 was rarely a cause of bronchiolitis in children younger than 24 months of age.

Acute bronchiolitis represents the leading cause of hospitalization in infants. Together with a respiratory syncytial virus, rhinovirus (RV) is one of the most common pathogens associated with bronchiolitis, and its genetic diversity (>150 types) makes the recurrence of RV infections each year quite typical. The frequency of RV infection and co-infection with other viruses and its impact on the clinical course of bronchiolitis have been studied by several authors with controversial results. Some studies demonstrate that multiple virus infections result in more severe clinical presentation and a higher risk of complications, whereas other studies suggest no influence on clinical course. Moreover, RV bronchiolitis has been reported to potentially contribute to the development of long-term sequelae, such as recurrent wheezing and asthma, in the pediatric population. In the present review, we summarize the most recent findings of the role of RV infection in children with acute bronchiolitis, its impact on subsequent asthma development, and the implication in clinical practice.

Human Adenoviruses (HAdV) are known to be potentially associated with strong inflammatory responses and morbidity in pediatric patients. Although most of the primary infections are self-limiting, the severity of clinical presentation, the elevation of the white blood cell count and inflammatory markers often mimic a bacterial infection and lead to an inappropriate use of antibiotics. In infections caused by HAdV, rapid antigen detection kits are advisable but not employed routinely; costs and feasibility of rapid syndromic molecular diagnosis may limit its use in the in-hospital setting; lymphocyte cultures and two-sampled serology are time consuming and impractical when considering the use of antibiotics. In this review, we aim to describe the principal diagnostic tools and the immune response in HAdV infections and evaluate whether markers based on the response of the host may help early recognition of HAdV and avoid inappropriate antimicrobial prescriptions in acute airway infections.

Respiratory syncytial virus (RSV) represents the main cause of acute respiratory tract infections in children worldwide and is the leading cause of hospitalization in infants. RSV infection is a self-limiting condition and does not require antibiotics. However hospitalized infants with clinical bronchiolitis often receive antibiotics for fear of bacteria coinfection, especially when chest radiography is performed due to similar radiographic appearance of infiltrate and atelectasis. This may lead to unnecessary antibiotic prescription, additional cost, and increased risk of development of resistance. Despite the considerable burden of RSV bronchiolitis, to date, only symptomatic treatment is available, and there are no commercially available vaccines. The only licensed passive immunoprophylaxis is palivizumab. The high cost of this monoclonal antibody (mAb) has led to limiting its prescription only for high-risk children: infants with chronic lung disease, congenital heart disease, neuromuscular disorders, immunodeficiencies, and extreme preterm birth. Nevertheless, it has been shown that the majority of hospitalized RSV-infected children do not fully meet the criteria for immune prophylaxis. While waiting for an effective vaccine, passive immune prophylaxis in children is mandatory. There are a growing number of RSV passive immunization candidates under development intended for RSV prevention in all infants. In this review, we describe the state-of-the-art of palivizumab’s usage and summarize the clinical and preclinical trials regarding the development of mAbs with a better cost-effectiveness ratio.

Silver–Russell syndrome (SRS) is a clinically and genetically heterogeneous syndrome characterized by severe intrauterine and postnatal growth retardation, facial dysmorphism and body asymmetry. One of the main molecular mechanisms leading to the syndrome involves methylation abnormalities of chromosome 11p15. In the last decades, an increase of imprinting disorders have been reported in children born from assisted reproductive technology (ART); however there is currently little evidence linking SRS and ART. Only few infants with SRS born using ART, supported by molecular analysis, have been described. We report on a twin-girl conceived using intracytoplasmic sperm injection (ICSI) diagnosed with SRS. Molecular studies revealed a hypomethylation of the paternal H19/IGF2 Imprinting Control Region. Her twin sister had a normal prenatal and postnatal growth and a normal methylation pattern of the chromosome 11p15. This is the second reported case of a twin infant with SRS conceived using ART with hypomethylation of H19/IGF2; it provides additional evidence of a possible relationship between ART procedures and methylation defects observed in SRS. Given the clinical heterogeneity of SRS, and the increased risk of multiple and preterm births in the ART-conceived children, it is possible that a number of cases of SRS remains undiagnosed in this population. Future studies should investigate the possible link between ART and SRS, in order to better understand the causes of epimutations in ART pregnancies, and to help clinicians to adequately counsel parents who approach to ART and to assess the opportunity of a long-term follow-up of children conceived using ART.