Epidemiology and Natural History of Childhood-Acquired Chronic Hepatitis C: A Single-Center Long-Term Prospective Study.

OBJECTIVES: To prospectively describe the epidemiology and long-term outcome of childhood-acquired hepatitis C virus (HCV) infection in a large cohort of children followed at a single center. METHODS: All children with chronic HCV infection followed at the Liver Unit of our tertiary Hospital in Florence (Italy) from January 1, 1988, to September 30, 2021, were included in the analysis. RESULTS: The final sample consisted of 163 children (median age at enrollment 4 years, interquartile range (IQR): 10; median age at last follow-up 14 years, IQR: 7). The median duration of follow-up was 86 months (IQR: 112). One hundred twenty-five children were vertically infected and 26 acquired the infection horizontally. Twenty-six of the 125 children who were vertically infected (20.8%) underwent spontaneous clearance of HCV RNA at a median age of 4 years (IQR: 2), whereas all the others remained persistently viremic. One patient was diagnosed with cirrhosis; 2 presented clinically detectable extrahepatic manifestations (chronic urticaria). Thirty-two children (19.6%) received antiviral therapy: 8 out of 32 (25%) were treated with pegylated-interferon alfa-2b [sustained virological response (SVR) 24 weeks after the end of treatment in 7/8]; 24 out of 32 (75%) were treated with direct-acting antivirals (SVR 12 weeks after the end of treatment in 23/24). CONCLUSIONS: The present study describes the largest cohort of children with chronic HCV infection prospectively evaluated with a long follow-up at a single center. HCV infection in children is often a chronic infection that can be cured with modern antiviral therapy. Early treatment could prevent the development of advanced liver disease.

Gastrointestinal and hepatic involvement in paediatric systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a multisystemic, autoimmune, inflammatory disease. Gastrointestinal (GI) involvement, extensively described in adults, is less characterised in paediatric-onset SLE (pSLE). The aim of the present narrative review was to provide a comprehensive summary and update on GI involvement in pSLE. A literature search on PubMed and EMBASE was conducted to identify original articles, reviews, case series and editorials published in English from 2000 to 31 August 2020. Based on this, we reported the prevalence, pathogenetic mechanisms, clinical issues, diagnostic tools and management of each form of GI involvement in pSLE. Lupus enteritis is the most frequent type of GI involvement in pSLE, followed by intestinal pseudo-obstruction, protein-losing enteropathy, hepatic disease and acute pancreatitis. The most common presenting GI symptoms are non-specific and include abdominal pain, anorexia, nausea, vomiting. In most cases, they are associated with other clinical and laboratory manifestations of SLE. The complications of GI involvement, including perforation and intestinal infarction, can be life-threatening. Laboratory findings and imaging studies can help to rule out non-SLE related causes for GI manifestations and to reveal typical features of the single forms of GI involvement. Early diagnosis and treatment are crucial to improve prognosis and avoid unnecessary surgery. Most SLE GI manifestations respond well to glucocorticoids and immunosuppressants. In conclusion, GI involvement is frequent in pSLE and its diagnosis and management can be a challenge for clinicians. In view of the limited available data, further studies are needed to better explore the prevalence, prognosis and treatment recommendations for GI involvement in pSLE.

Gastrointestinal involvement in childhood vasculitides.

AIM: The aim of this narrative review was to provide a comprehensive summary of the characteristics of gastrointestinal (GI) involvement in the most common paediatric primary vasculitides. METHODS: We used PubMed to primarily identify papers, reviews, case series and editorials published in English from 2000 until 31 January 2020. Based on this, we report the prevalence, clinical manifestations, diagnostic approaches and management of GI involvement in each vasculitis. RESULTS: Vasculitides are inflammatory blood vessel diseases, and the majority can affect the GI system with vascular, GI tract or solid organ involvement. GI involvement can sometimes complicate and delay the correct diagnosis. Clinical findings are usually nonspecific symptoms, such as fever, abdominal pain, nausea, vomiting and diarrhoea. Bleeding should alert paediatricians to the possibility of severe complicated vasculitis. Diagnosis relies mostly on imaging. If it goes unrecognised, GI involvement in paediatric vasculitis is a serious cause of morbidity and even mortality, related to bowel ischaemia and perforation. Treatment of GI symptoms depends on the type of vasculitis and usually involves high-dose steroids and immunosuppressants. CONCLUSION: GI manifestations in the most common paediatric primary vasculitides were usually nonspecific, diagnosis mostly relied on imaging, and treatment usually involved high-dose corticosteroids and immunosuppressants.

Characteristics and outcome of influenza-associated encephalopathy/encephalitis among children in a tertiary pediatric hospital in Italy, 2017-2019.

BACKGROUND: Influenza is the most frequent cause of acute upper respiratory tract infections during winter season. Although rare, neurological manifestations are known to occur during influenza infection and approximatively three-quarters of cases are in children. In this study, we aimed to characterize the burden and clinical spectrum of influenza-associated encephalopathy and encephalitis in children admitted at a tertiary pediatric hospital in Italy over two influenza seasons (2017-2019). METHODS: We retrospectively analyzed clinical, laboratory, instrumental data and outcome of patients discharged with ICD9-CM 487.0 code. RESULTS: Fifteen children (13.1% of those discharged with a diagnosis of influenza infection in the study period), had influenza-associated central nervous system (CNS) manifestations. Eight patients (53.3%) were diagnosed as influenza encephalitis, 7 (46.7%) as influenza encephalopathy. Median age was 27 months. In children under 2 years of age (40% of all cases) altered consciousness was the most frequent neurological manifestation while respiratory symptoms were present at admission in all cases. Younger children also required intensive care support more frequently. Five subjects (33.3%) presented comorbidity. None of the patients had received seasonal influenza vaccination. The median time from onset of respiratory signs to onset of neurological manifestations was 24 h. Cerebrospinal fluid (CSF) analysis was normal in most patients and polymerase chain reaction for influenza virus RNA on CSF, when performed, was negative in all samples. Neuroradiological investigations, performed in 5 children, reported cortical and subcortical white matter signal alterations. Oseltamivir was administered only in 2 cases. Fourteen patients recovered without sequelae, and only a 2-year-old girl had minimal impairment in fine motor skills at discharge. CONCLUSIONS: All children presenting acute neurological features during influenza season should be evaluated for influenza-associated CNS complications even if the respiratory involvement is mild. Absence of underlying diseases or other risk factors are not protective factors against CNS influenza-associated complications. The lack of CSF pleocytosis does not exclude CNS involvement. Children under 2 years of age are at higher risk of requiring intensive care support.

COVID-19 and Thromboembolic Events in the Pandemic and Pre-Pandemic Era: A Pediatric Cohort.

The Coronavirus disease 2019 (COVID-19) and multisystem inflammatory syndrome in children (MIS-C) have been variably associated with thromboembolic events (TEs) in children. The aim of our study was to assess the prevalence of TEs in children hospitalized during a five-year period in a tertiary pediatric hospital, particularly in patients with COVID-19 and MIS-C. Overall, 38 patients were discharged with the diagnosis of TE: 20 in the pre-pandemic and 18 in the pandemic period. The prevalence of TEs was the same (0.08%) in the pre-pandemic and pandemic periods. The occurrence of TEs was higher in patients with COVID-19 or MIS-C (6/517, 1.16%) when compared to children without these conditions in the pandemic and in the pre-pandemic periods. The prevalence of TEs in children with MIS-C was significantly higher than the prevalence in patients with COVID-19. Five out of six of the patients with COVID-19 or MIS-C developing a TE had at least one predisposing factor to thrombosis. In conclusion, our study shows an increased prevalence of TEs in children hospitalized with COVID-19 or MIS-C, if compared to children without COVID-19 or MIS-C in the pandemic period and in the pre-pandemic period. The prevalence of TEs was significantly higher in patients with MIS-C.

A Narrative Review on Pediatric Scurvy: The Last Twenty Years.

Scurvy is a well-known clinical condition caused by vitamin C deficiency. Although considered a rare disease in high-income countries, it has been recently increasingly reported in children, especially in those with abnormal dietary habits, mental or physical disabilities. We performed an extensive review of the literature analyzing studies published in the last 20 years focusing on clinical features, differential diagnosis and diagnostic delay. Fifteen articles were selected, collectively reporting a total of 166 children. Because of the wide clinical spectrum (musculoskeletal complaints and/or mucocutaneous lesions or systemic symptoms), scurvy can mimic several conditions, including autoimmune diseases, infections, and neoplasia. In addition, frequent findings such as normal nutritional status, anemia or elevated inflammatory markers may guide clinicians towards the abovementioned misdiagnoses. Scurvy should be considered in patients presenting with musculoskeletal complaints, not only in those with risk factors but also in healthy children. A focused dietary history and a careful physical examination, assessing other signs of vitamin C deficiency, are mandatory in these patients. When suspected, the dosage of serum vitamin C is the diagnostic gold standard; furthermore, imaging studies, performed by an expert radiologist, can reveal the typical features of scurvy. Only early diagnosis can avoid unnecessary investigations and potentially fatal complications of the disease.

Erythema Nodosum in Children: A Narrative Review and a Practical Approach.

Erythema nodosum (EN) is the most frequent form of panniculitis in children. We performed a literature review analyzing studies on pediatric EN published from 1990 to February 2022. EN is rare in pediatric age. It can be primary/idiopathic in 23-55% cases, or secondary in 47-77% cases. Secondary EN is related to a wide variety of conditions including infectious diseases, autoimmune disorders, malignancy, drugs, vaccinations, and pregnancy. The diagnosis of EN is clinical, based on the acute appearance of painful and red nodules localized to lower limbs, bilaterally distributed. If EN is diagnosed, basic work-up should include inflammatory markers, serum aminotransferases, lactate dehydrogenase, creatinine, protein electrophoresis, immunoglobulins, testing for streptococcal infection, and a tuberculin skin test. Based on the medical history and associated manifestations, further laboratory and radiological exams should be performed. The prognosis of EN is excellent, with spontaneous resolution in most patients within 2-6 weeks. Treatment, if needed, is addressed to the underlying condition. Despite being a rare manifestation in children, EN can be isolated or the first manifestation of a systemic or infectious condition. EN diagnosis is clinical, and a high index of suspicion is needed to perform investigations for the underlying disorders.

When the limp has a dietary cause: A retrospective study on scurvy in a tertiary Italian pediatric hospital.

The limping child frequently represents a diagnostic challenge. The differential diagnosis is broad and should include vitamin C deficiency. Scurvy, resulting from vitamin C deficiency, is the oldest-known nutritional disorder. Despite its rarity in developed countries, scurvy has been increasingly reported in recent years in pediatric patients, particularly those with autism or neurological disabilities. In the present retrospective study, we describe the clinical, laboratory, and radiological features of 8 patients diagnosed with scurvy in the Pediatrics Unit of Meyer Children's University Hospital, between January 2016 and December 2021. The majority (87%) were males, and the median age was 3.7 years. Half of the patients had comorbidities known to be risk factors for scurvy, while the remaining patients were previously healthy. All the children were admitted for musculoskeletal symptoms, ranging from lower limb pain (87%) to overt limping (87%). Mucocutaneous involvement was observed in 75% cases. Microcytic anemia and elevated inflammatory markers were common laboratory findings. Bone radiographs, performed on all patients, were often interpreted as normal at first, with osteopenia (62%) as the most frequent finding; notably, after re-examination, they were reported as consistent with scurvy in four patients. The most common magnetic resonance imaging findings were multifocal symmetrical increased signal on STIR sequence within metaphysis, with varying degrees of bone marrow enhancement, adjacent periosteal elevation and soft tissue swelling. Differential diagnosis was challenging and frequently required invasive diagnostic procedures like bone marrow biopsy, performed in the first three patients of our series. The median time frame between clinical onset and the final diagnosis was 35 days. Notably, the interval times between admission and diagnosis become progressively shorter during the study period, ranging from 44 to 2 days. Treatment with oral vitamin C led to improvement/resolution of symptoms in all cases. In conclusion, scurvy should be considered in the differential diagnosis in a limping child, performing a detailed dietary history and careful physical examination, looking for mucocutaneous lesions. A quick and correct diagnostic path avoids invasive diagnostic procedures and reduces the risk of long-term complications.

Diencephalic syndrome in childhood, a challenging cause of failure to thrive: miniseries and literature review.

The aim of our study was to better define the clinical pattern of diencephalic syndrome, a rare but potentially lethal cause of failure to thrive in infancy. Poor weight gain or weight loss, the characteristic presenting feature, often firstly attributed to gastrointestinal or endocrinological or genetic diseases, is secondary to a malfunctioning hypothalamus, caused by a diencephalic tumor. Due to its unexpected clinical onset, diagnostic delay and misdiagnosis are common. We described a case series of 3 children with diencephalic syndrome admitted at our Hospital, over a 5-year period. Furthermore, a narrative review on all pediatric cases published in the last seventy years was performed. Clinical pattern, timing to diagnosis, neuroimaging, management, and outcome were analyzed. Our three cases are singularly described in all clinical and diagnostic findings. Overall, 100 children were selected; all these cases as well as our children presented with failure to thrive: 96% had body mass index or weight-length/height ratio lower than 5th percentile. Vomiting and hyperactivity are reported in 35 and 26% of cases, respectively. The neurological features, mainly nystagmus reported in 43%, may occur late in the disease course. In conclusion, the diagnostic delay is the hallmark of diencephalic syndrome, confirming the lack of knowledge by clinicians. The poor weight gain/loss despite adequate length growth and food intake, especially in children with hyperactivity and good psychomotor development, should alert pediatricians towards this condition, before neurological signs/symptoms occurrence.

Thromboembolic complications in children with COVID-19 and MIS-C: A narrative review.

COVID-19 and multisystem inflammatory syndrome in children (MIS-C) have been associated with a higher incidence of hypercoagulability and thromboembolic events (TEs), even in children, leading to relevant morbidity, and mortality. However, our understanding of such complications in childhood is limited. To better understand the incidence, clinical manifestations, risk factors, and management of COVID-19 and MIS-C-related TEs in children, a review of the current literature and a brief update on pathophysiology are given. Sixty-two studies, describing 138 patients with TEs associated with COVID-19 or MIS-C, were included. The overall number of TEs was 157, as 16 patients developed multiple TEs: venous TEs represented the majority (54%), followed by arterial thrombosis (38%, mainly represented by arterial ischemic stroke-AIS), and intracardiac thrombosis (ICT) (8%). Within the venous TEs group, pulmonary embolism (PE) was the most frequent, followed by deep venous thrombosis, central venous sinus thrombosis, and splanchnic venous thrombosis. Notably, 10 patients had multiple types of venous TEs, and four had both venous and arterial thrombosis including a newborn. Most of them (79 cases,57%) had at least one predisposing condition, being obesity the most frequent (21%), especially in patients with PE, followed by malignancy (9%). In 35% of cases, no data about the outcome were available About one-third of cases recovered, 12% improved at discharge or follow-up, and 6% had persistent neurological sequelae. The mortality rate was 12%, with death due to comorbidities in most cases. Most fatalities occurred in patients with arterial thrombosis. Pediatricians should be aware of this life-threatening possibility facing children with SARS-CoV-2 infection or its multisystemic inflammatory complication, who abruptly develop neurological or respiratory impairment. A prompt intensive care is essential to avoid severe sequelae or even exitus.

Treatment of hepatitis B virus infection in children and adolescents.

Hepatitis B virus (HBV) infection is one of the main causes of morbidity and mortality worldwide. Most children acquire the infection perinatally or during early childhood and develop a chronic hepatitis characterized by a high viral replication and a low-inflammation phase of infection, with normal or only slightly raised aminotransferases. Although a conservative approach in children is usually recommended, different therapies exist and different therapeutic approaches are possible. The main goals of antiviral treatment for children with chronic HBV infection are to suppress viral replication and to warn the disease progression to cirrhosis and hepatocellular carcinoma, although these complications are rare in children. Both United States Food and Drug Administration (US-FDA) and European Medicines Agency (EMA) have approved interferon alfa-2b for children aged 1 year and older, pegylated interferon alfa-2a and lamivudine for children aged 3 years and older, entecavir for use in children aged 2 years and older, and adefovir for use in those 12 years of age and older. Tenofovir disoproxil fumarate is approved by EMA for children aged 2 years and older and by US-FDA for treatment in children aged 12 years and older. Finally, EMA has approved the use of tenofovir alafenamide for treatment of children aged 12 years and older or for children weighing more than 35 kg independent of age. This narrative review will provide the framework for summarizing indications to antiviral therapy in the management of chronic HBV infection in children and adolescents.

Sofosbuvir/velpatasvir for the treatment of hepatitis C in pediatric patients.

Introduction: Sofosbuvir/velpatasvir is a combination of direct-acting antivirals with pangenotypic activity for treatment of chronic hepatitis C virus infection. It was approved in 2020 for use in children aged 6-17 years and in June 2021 by the United States Food and Drug Administration for the age group 3-5 years.Areas covered: A literature search of PUBMED and EMBASE was conducted on April 30th and updated on June 10th. Other citations were identified in references of available literature and from ClinicalTrials.gov. The aim of the present research was to outline and discuss the pharmacokinetics, clinical efficacy, tolerability and safety of sofosbuvir/velpatasvir, exploring its actual and potential use in children and adolescents with chronic hepatitis C virus infection.Expert opinion: Five combinations of direct-acting antivirals, of whom three with pangenotypic activity, are now approved for children. No major differences in efficacy and safety profile have been described. Limited access to treatment still is a major issue, especially in low and middle-income countries.

Gastrointestinal involvement in IgA vasculitis: a single-center 11-year study on a cohort of 118 children.

INTRODUCTION AND OBJECTIVES: Immunoglobulin A vasculitis (IgAV), the most common childhood vasculitis, is associated with gastrointestinal (GI) involvement in 50-75% of cases. The aim of this study was to describe the characteristics of GI involvement in a cohort of hospitalized children with IgAV. METHODS: We retrospectively evaluated patients hospitalized for IgAV at Meyer Children's University Hospital, from January 2010 to December 2020. The children's families were interviewed by phone and asked about disease relapses. RESULTS: In the study period, 118 children had GI involvement, corresponding to 75% of children hospitalized for IgAV. Their median age was 7 years (interquartile range 6-9). The most frequent GI manifestations were abdominal pain (96%), bleeding (71%, mostly occult), vomiting (58%), and diarrhea (17%). GI complications, observed in 18%, were intussusception (14%), appendicitis (3%), gallbladder hydrops (2%), and ileal perforation (1%). Abdomen ultrasound, performed in all cases, was abnormal in 68%. Abdomen X-ray, performed in 19 patients, showed pathologic findings in 84% of them. Selected children with severe manifestations also underwent abdomen computed tomography (2/118; 2%) and GI endoscopy (5/118; 4%). Steroids were used in 80 (67.8%) cases. The use of second- and third-line therapies was necessary in three cases. Relapses, investigated in 80 cases (68%), occurred in 21% of them. Key Points • The present retrospective study describes a cohort of 118 patients hospitalized for gastrointestinal (GI) involvement in immunoglobulin A vasculitis (IgAV) at a tertiary care children's hospital from January 2010 to December 2020. • The most frequent GI manifestations were abdominal pain (96%), vomiting (58%), and diarrhea (17%). GI bleeding was reported in 71% of children, and it was occult in most cases. • GI complications, occurring in 18% of cases, were intussusception (14%), appendicitis (3%), gallbladder hydrops (2%), and ileal perforation (1%). • Steroid treatment has been successfully used in severe GI manifestations; however, our data do not support its association with low relapse risk. CONCLUSIONS: The present study describes a large pediatric cohort of GI involvement in IgAV. Steroid treatment should be used when GI manifestations are severe. The association of steroid use with relapse risk is not currently established.

Necrotizing pneumonia among Italian children in the pneumococcal conjugate vaccine era.

BACKGROUND: Necrotizing pneumonia (NP) is a severe complication of community-acquired pneumonia. The impact of 13-valent pneumococcal conjugate vaccine (PCV13) on the epidemiology of NP in children has not been assessed. PATIENTS AND METHODS: Medical records of children less than 18 years admitted with NP to two pediatric hospitals in Italy between 2005 and 2019 were reviewed. The following four periods were defined: 2005-2010 (pre-PCV13), 2011-2013 (early post-PCV13), 2014-2016 (intermediate post-PCV13), and 2017-2019 (late post-PCV13). RESULTS: Forty-three children (median age, 44 months) were included. Most of them (93%) were previously healthy. No differences in age, sex, season of admission, comorbidity, clinical presentation, or hospital course were identified between pre-PCV13 and post-PCV13 periods. A significant decrease in the rate of NP-associated hospitalizations was found between the early (1.5/1000 admissions/year) and the intermediate (0.35/1000 admissions/year) post-PCV13 period (p = .001). An increased trend in admissions was found thereafter. Streptococcus pneumoniae was the most common agent detected in both periods (pre-PCV13: 11/18, 61%; post-PCV13: 13/25, 52%). Serotype 3 was the most common strain in both periods (pre-PCV13: 3/11, 27%; post-PCV13; 4/13, 31%). There were no changes in the etiology over time, but most patients with Streptococcus pyogenes or Staphylococcus aureus infection were admitted during the post-PCV13 period. CONCLUSIONS: The hospitalization rate for NP in children decreased a few years after the implementation of PCV13 immunization in Italy. However, an increased trend in admissions was found thereafter. S. pneumoniae was the most frequent causal agent in both pre- and post-PCV13 periods. Pneumococcal serotypes were mainly represented by Strain 3.

Recurrent Bilateral Salpingitis in a Sexually Inactive Adolescent: Don't Forget about the Appendix.

BACKGROUND: Salpingitis is an acute inflammation of the fallopian tubes and is extremely uncommon in patients who are sexually inactive or premenarchal. CASE: We describe a 15-year-old sexually inactive patient with recurrent bilateral salpingitis. After the second episode, she underwent an exploratory laparoscopy and was diagnosed with chronic appendicitis. SUMMARY AND CONCLUSION: Appendicular involvement should be kept in mind in recurrent salpingitis episodes, especially if previous imaging studies do not show signs of appendicitis. Imaging studies should be repeated in experienced centers in case of recurrent episodes. Laparoscopy is the gold standard for the diagnosis of salpingitis and can confirm appendicular or other abdominal involvement. Early diagnosis can help to prevent recurrent episodes of salpingitis and thus reduce the risk of sequelae.

Case Report: Perioperative Kounis Syndrome in an Adolescent With Congenital Glaucoma.

A 12-year-old male patient suffering from congenital glaucoma developed bradycardia, left ventricular failure, and hypotension after induction of anesthesia. Electrocardiography and echocardiography revealed a complete normalization of ECG and a complete spontaneous recovery in the cardiac function 72 hours from the beginning of the clinical manifestations, while cardiac Magnetic Resonance Imaging was performed, and coronary Computed Tomography scan revealed a myocardial bridge of a tract of the left anterior descendent coronary artery. Diagnosis of Kounis syndrome (KS) was made, a relatively novel, under-recognized clinical condition, defined as the manifestation of an acute coronary syndrome accompanied by mast cell activation and platelet aggregation involving interrelated and interacting inflammatory cells in the setting of allergic, hypersensitivity, anaphylactic or anaphylactoid insults. We described one of the first pediatric cases of KS related to anesthetic medications. In children, this syndrome has been only described in isolated case reports or small case series. Thus, it appears critical to report new cases of KS in children to increase the awareness of this disease in pediatric healthcare workers so as to enhance its early recognition and optimal therapeutic strategy. Furthermore, it appears of paramount importance the implementation of universal guidelines accepted by allergology and cardiology societies, in order to standardize the management of pediatric and adult patients with KS. Finally, a close collaboration between pediatric allergists and cardiologists seems fundamental for an optimal multidisciplinary patient care.

Parent-Collected Nasal Swab for Severe Acute Respiratory Syndrome Coronavirus 2 Testing in Children.

This cross-sectional study, including children hospitalized for severe acute respiratory syndrome coronavirus 2 infection, demonstrates for the first time that nonhealthcare worker parents perform similarly to healthcare workers in the administration to their children of an unsupervised nasal swab for severe acute respiratory syndrome coronavirus 2 detection by following written instructions and video tutorials.

Performance Characterization of Broad Band Sustainable Sound Absorbers Made of Almond Skins.

In order to limit the environmental impact caused by the use of non-renewable resources, a growing research interest is currently being shown in the reuse of agricultural by-products as new raw materials for green building panels. Moreover, the European directives impose the goal of sustainability supporting the investigation of passive solutions for the reduction of energy consumption. Thus, the promotion of innovative building materials for the enhancement of acoustic and thermal insulation of the buildings is an important issue. The aim of the present research was to evaluate the physical, acoustical, and thermal performances of building panels produced by almond skin residues, derived from the industrial processing of almonds. In this paper different mix designs were investigated using polyvinyl acetate glue and gum Arabic solution as binders. Air-flow resistivity σ and normal incidence sound absorption coefficient α were measured by means of a standing wave tube. Thermal conductivity λ, thermal diffusivity α, volumetric heat capacity ρc were measured using a transient plane source device. Finally, water vapor permeability δp was experimentally determined using the dry cup method. Furthermore, a physical characterization of the specimens in terms of bulk density ρb and porosity η allowed to study the correlation existing between the binder and the aggregates and the consequent acoustical and hygrothermal behavior occurring on the different mix designs. The achieved results suggested the investigated materials comparable to the main products currently existing on the market.

Neisseria meningitidis with H552Y substitution on rpoB gene shows attenuated behavior in vivo: report of a rifampicin-resistant case following chemoprophylaxis.

We present the first Italian reported case of an invasive meningococcal disease with rifampicin-resistance (Rif-R)secondary to chemoprophylaxis. The case is entered in a cluster of two IMDs registered in Tuscany, Italy, in November 2019 caused by two non-differentiable group-C Neisseria meningitidis belonging to ST-11 clonal-complex. The contact case, differently from the index, harbored H552Y mutation on rpoB gene which is known to confer Rif-R putting a high-cost fee on bacterial fitness. The extremely mild clinical presentation in the contact can constitute an in vivo demonstration of the virulence attenuation observed in vitro for H552Ymutants. Clinicians should be aware of the possibility of secondary cases with induced Rif-R and keep a high level of suspicion on contacts who received rifampicin-chemoprophylaxis. Molecular characterization of Rif-R should be performed routinely directly on biological samples and not only on isolates, in order to rapidly detect rare cases of resistance and consequently modify chemoprophylaxis for contacts.