Ambra Nicolai

Rapid spread of the novel respiratory syncytial virus a on1 genotype, central Italy, 2011 to 2013

Respiratory infections positive for human respiratory syncytial virus (RSV) subtype A were characterised in children admitted to hospitals in Rome and Ancona (Italy) over the last three epidemic seasons. Different strains of the novel RSV-A genotype ON1, first identified in Ontario (Canada) in December 2010, were detected for the first time in Italy in the following 2011/12 epidemic season. They bear an insertion of 24 amino acids in the G glycoprotein as well as amino acid changes likely to change antigenicity. By early 2013, ON1 strains had spread so efficiently that they had nearly replaced other RSV-A strains. Notably, the RSV peak in the 2012/13 epidemic season occurred earlier and, compared with the previous two seasons, influenza-like illnesses diagnoses were more frequent in younger children; bronchiolitis cases had a less severe clinical course. Nonetheless, the ON1-associated intensive care unit admission rate was similar, if not greater, than that attributable to other RSV-A strains. Improving RSV surveillance would allow timely understanding of the epidemiological and clinicopathological features of the novel RSV-A genotype.

Recurrent wheezing 36 months after bronchiolitis is associated with rhinovirus infections and blood eosinophilia

Links between respiratory syncytial virus bronchiolitis and asthma are well known, but few studies have dealt with wheezing following bronchiolitis induced by other viruses. We assessed the risk factors for recurrent wheezing in infants hospitalised for acute viral bronchiolitis.

Interferon lambda 1–3 expression in infants hospitalized for RSV or HRV associated bronchiolitis

Summary Objectives The airway expression of type III interferons (IFNs) was evaluated in infants hospitalized for respiratory syncytial virus (RSV) or rhinovirus (HRV) bronchiolitis. As an additional objective we sought to determine whether a different expression of IFN lambda 1–3 was associated with different harboring viruses, the clinical course of bronchiolitis or with the levels of well established IFN stimulated genes (ISGs), such as mixovirus resistance A (MxA) and ISG56. Methods The analysis was undertaken in 118 infants with RSV or HRV bronchiolitis. Nasopharyngeal washes were collected for virological studies and molecular analysis of type III IFN responses. Results RSV elicited higher levels of IFN lambda subtypes when compared with HRV. A similar expression of type III IFN was found in RSVA or RSVB infected infants and in those infected with HRVA or HRVC viruses. Results also indicate that IFN lambda 1 and IFN lambda 2–3 levels were correlated with each other and with MxA and ISG56-mRNAs. In addition, a positive correlation exists between the IFN lambda1 levels and the clinical score index during RSV infection. In particular, higher IFN lambda 1 levels are associated to an increase of respiratory rate. Conclusions These findings show that differences in the IFN lambda 1–3 levels in infants with RSV or HRV infections are present and that the expression of IFN lambda 1 correlates with the severity of RSV bronchiolitis.

Bordetella pertussis in infants hospitalized for acute respiratory symptoms remains a concern

BackgroundPreliminary results suggest that pertussis infection might be considered in infants during a seasonal respiratory syncytial virus (RSV) outbreak.MethodsIn order to analyze clinical features and laboratory findings in infants with pertussis hospitalized for acute respiratory symptoms during a seasonal RSV outbreak, we conducted a retrospective single-center study on 19 infants with pertussis (6 boys; median age 72 days) and 19 matched controls (RSV-bronchiolitis), hospitalized from October 2008 to April 2010. B. pertussis and RSV were detected from nasopharyngeal washes with Real Time-PCR.ResultsInfants with pertussis were less often breastfeed than infants with RSV bronchiolitis (63.2% vs 89.5%; p <0.06). Clinically, significantly fewer infants with pertussis than controls had more episodes of whooping cough (63.2% vs 0.0%; p < 0.001) and also less frequently fever at admission (15.8% vs 68.4%; p <0.01), apnea (52.6% vs 10.5%; p <0.006), and cyanosis (52.6% vs 10.5%; p < 0.006). Infants with pertussis had more often no abnormal chest sounds on auscultation than infants with RSV bronchiolitis (0% vs 42,1%; p < 0.005). The absolute blood lymphocyte and eosinophil counts were higher in infants with B. pertussis than in controls with bronchiolitis (23886 ± 16945 vs 10725 ± 4126 cells/mm3, p < 0.0001 and 13.653 ± 10.430 vs 4.730 ± 2.400 cells/mm3, p < 0.001). The molecular analysis of 2 B. pertussis isolates for ptxA1, ptxP3, and prn2 genes showed the presence of gene variants.ConclusionsWhen infants are hospitalized for acute respiratory symptoms, physicians should suspect a pertussis infection, seek for specific clinical symptoms, investigate lymphocyte and eosinophil counts and thus diagnose infection early enough to allow treatment.

Viral Load in Infants Hospitalized for Respiratory Syncytial Virus Bronchiolitis Correlates with Recurrent Wheezing at Thirty-Six-Month Follow-Up.

The relationship between viral infection, host immune response in infants with respiratory syncytial virus (RSV) bronchiolitis and subsequent wheezing is discussed. We measured RSV-RNA load and interferon-&lgr;1–3 expression in the nasopharyngeal washings from 68 infants hospitalized for RSV bronchiolitis, and wheezing was assessed 36 months after the first episode of bronchiolitis. Higher RSV-RNA load and higher interferon-&lgr;2/3 levels were found in children with recurrent wheezing at 36-month follow-up.

Seven Percent Hypertonic Saline—0.1% Hyaluronic Acid in Infants With Mild-To-Moderate Bronchiolitis

Our study was aimed to evaluate the efficacy of 7% hypertonic saline and 0.1% hyaluronic acid (7% HS–HA) given by inhalation, in infants hospitalized for mild‐to‐moderate bronchiolitis.

Viral bronchiolitis in children: A common condition with few therapeutic options☆

Abstract Even though bronchiolitis is a disease that has been recognized for many years, there are still few therapeutic strategies beyond supportive therapies. Bronchiolitis is the most frequent cause of hospital admission in children less than 1 year of age. The incidence is estimated to be about 150° million cases a year worldwide, and 2–3% of these cases require hospitalization. It is acknowledged that viruses cause bronchiolitis, but most of the studies focus on RSV. The RSV causes a more severe form of bronchiolitis in children with risk factors including prematurity, cardiovascular disease and immunodeficiency. Other viruses involved in causing bronchiolitis include RV, hMPV, hBoV and co-infections. The RV seems to be associated with a less severe acute disease, but there is a correlation between the early infection and subsequent wheezing bronchitis and asthma in later childhood and adulthood. The supportive therapies used are intravenous fluids and oxygen supplement administered by nasal cannula or CPAP in most complicated patients. Additional pharmacological therapies include epinephrine, 3% hypertonic saline and corticosteroids. The Epinephrine seems to have the greatest short-term benefits and reduces the need of hospital admission, whereas hypertonic saline and corticosteroids seem to reduce the length of hospital stay. As bronchiolitis is such a prevalent disease in children and RV seems to play an important role, perhaps more studies should center around the RVs contribution to the initial disease and following pathology.

Bronchiolitis: Analysis of 10 consecutive epidemic seasons

Bronchiolitis is the leading cause of hospitalization in infants under 12 months. Our aims were to analyze epidemiological characteristics of infants with bronchiolitis over 10 consecutive seasons and to evaluate whether there are any clinical differences between infants hospitalized for bronchiolitis during epidemic peak months and infants in non‐peak months. We enrolled consecutive enrolled 723 previously healthy term infants hospitalized at the Paediatric Emergency Department, “Sapienza” University of Rome over the period 2004–2014. Fourteen respiratory viruses were detected from nasopharyngeal aspirates by molecular methods. Clinical and demographic data were extracted from clinical charts. Viruses were detected in 351 infants (48.5%): RSV in 234 (32.4%), RV in 44 (6.1%), hBoV in 11 (1.5%), hMPV in 12 (1.6%), co‐infections in 39 (5.4%), and other viruses in 11 (1.5%). Analyzing the 10 epidemic seasons, we found higher incidence for bronchiolitis every 4 years with a peak during the months December–January. Infants hospitalized during peak months had lower family history for asthma (P = 0.003), more smoking mothers during pregnancy (P = 0.036), were slightly higher breastfed (0.056), had lower number of blood eosinophils (P = 0.015) and had a higher clinical severity score (P = 0.017). RSV was detected mostly during peak months, while RV was equally distributed during the seasons. We found some variations in bronchiolitis incidence during epidemics, and discriminative characteristics in infants hospitalized for bronchiolitis during peak months and in non‐peak months, that might reflect two different populations of children. Pediatr Pulmonol. 2016;51:1330–1335.

Risk Factors for Virus-induced Acute Respiratory Tract Infections in Children Younger Than 3 Years and Recurrent Wheezing at 36 Months Follow-up After Discharge

Background: We sought to know more about how 14 common respiratory viruses manifest clinically, and to identify risk factors for specific virus-induced acute respiratory tract infections (ARTIs) in children younger than 3 years old and for wheezing at 36-month follow-up. Methods: We retrospectively studied the clinical records for 273 full-term children (median age, 2.9 months; range, 0.26–39; boys, 61.2%) hospitalized for ARTIs, whose nasopharyngeal specimen tested positive for a respiratory virus and 101 children with no history of respiratory diseases (median age, 8 months; range, 0.5–36.5; boys, 58.4%). At 12, 24 and 36 months after children’s discharge, all parents were interviewed by telephone with a structured questionnaire on wheezing episodes. Results: The most frequently detected viruses were respiratory syncytial virus in bronchiolitis, human rhinovirus in pneumonia and human bocavirus in wheezing. Multivariate analysis identified, as risk factors for virus-induced ARTIs, the presence of siblings [odds ratio (OR): 3.0 (95% confidence interval [CI]: 1.8–5.2)], smoking cohabitants (OR: 2.3 (95% CI: 2–4.2)] and breastfeeding lasting less than 3 months [OR: 0.5 (95% CI: 0.3–0.9)]. The major risk factor for respiratory syncytial virus–induced ARTIs was exposure to tobacco smoke [OR: 1.8 (95% CI: 1.1–3.2)]. Risk factors for human rhinovirus–induced ARTIs were attending day-care [OR: 5.0 (95% CI: 2.3–10.6)] and high eosinophil blood counts [OR: 2.6 (95% CI: 1.2–5.7)]. The leading risk factor for recurrent wheezing was exposure to tobacco smoke [OR: 2.5 (95% CI: 1.1–15.6)]. Conclusions: Each respiratory virus leads to a specific clinical manifestation. Avoiding exposing children to tobacco smoke might restrict viral spread from sick parents and siblings to younger children, prevent severe respiratory diseases, and possibly limit sequelae.

Respiratory syncytial virus bronchiolitis, weather conditions and air pollution in an Italian urban area: An observational study

Background In this study we sought to evaluate the association between viral bronchiolitis, weather conditions, and air pollution in an urban area in Italy. Methods We included infants hospitalized for acute bronchiolitis from 2004 to 2014. All infants underwent a nasal washing for virus detection. A regional agency network collected meteorological data (mean temperature, relative humidity and wind velocity) and the following air pollutants: sulfur dioxide, nitrogen oxide, carbon monoxide, ozone, benzene and suspended particulate matter measuring less than 10 &mgr;m (PM10) and less than 2.5 &mgr;m (PM2.5) in aerodynamic diameter. We obtained mean weekly concentration data for the day of admission, from the urban background monitoring sites nearest to each childs home address. Overdispersed Poisson regression model was fitted and adjusted for seasonality of the respiratory syncytial virus (RSV) infection, to evaluate the impact of individual characteristics and environmental factors on the probability of a being positive RSV. Results Of the 723 nasal washings from the infants enrolled, 266 (68%) contained RSV, 63 (16.1%) rhinovirus, 26 (6.6%) human bocavirus, 20 (5.1%) human metapneumovirus, and 16 (2.2%) other viruses. The number of RSV‐positive infants correlated negatively with temperature (p < 0.001), and positively with relative humidity (p < 0.001). Air pollutant concentrations differed significantly during the peak RSV months and the other months. Benzene concentration was independently associated with RSV incidence (p = 0.0124). Conclusions Seasonal weather conditions and concentration of air pollutants seem to influence RSV‐related bronchiolitis epidemics in an Italian urban area. HighlightsPeak RSV activity correlates with cold temperatures and higher relative humidity.RSV‐positive cases correlates positively with BZ, NOx, SO2, PM10 and PM2.5.The most predictive pollutant for RSV cases (constant temperature and humidity)is BZ.