Dynamics of nasopharyngeal pneumococcal carriage during the course of viral bronchiolitis.

The effect of viral infection on nasopharyngeal carriage of Streptococcus pneumoniae during childhood is not well known. We studied dynamics of pneumococcal colonization by quantitative PCR during the natural course of viral bronchiolitis. At time of admission, 47 (47%) of 100 patients with bronchiolitis carried pneumococci. In patients with viral bronchiolitis who did not receive antibiotics, pneumococcal load decreased from time of admission to discharge (n = 35, cycle threshold 23 vs. 25, P = 0.0017) and from discharge to follow-up (n = 22, cycle threshold 25 vs. 40, P = 0.003). We conclude that viral respiratory infection is negatively associated with pneumococcal colonization of the upper airways. Pediatr Pulmonol. 2016;51:863-867. © 2016 Wiley Periodicals, Inc.

Computerized Assessment of Wheezing in Children With Respiratory Syncytial Virus Bronchiolitis Before and After Hypertonic Saline Nebulization.

BACKGROUND: Studies suggest an effect of nebulized hypertonic saline solution on air-flow limitation in subjects with respiratory syncytial virus (RSV) bronchiolitis, but results are based on subjective scores of clinical severity and are not clear. In this observational study, we used a noninvasive computerized tool to quantify wheezing before and after nebulization with hypertonic saline in children admitted for RSV infection. METHODS: Twenty-seven children (≤ 24 months old) admitted to the pediatric ward of the Medical Center Leeuwarden with polymerase chain reaction-confirmed RSV bronchiolitis were included. Subjects were simultaneously assessed both clinically and by computerized acoustic monitoring before and 15 min after treatment with nebulized hypertonic saline solution. RESULTS: Clinical assessment, defined by the Respiratory Distress Assessment Instrument score, did not change after nebulization (n = 27, 5.0 vs 4.7, P = .17). Computerized acoustic monitoring showed no improvement in wheezing (n = 27, 3.4% vs 2.0%, P = .05) or inspiration/expiration ratio (0.85 vs 0.85, P = .93) after nebulization. CONCLUSIONS: Hypertonic saline nebulization does not improve air flow, as assessed by both clinical and computerized acoustic scores, in children admitted for RSV.

Symptoms and treatment of Dientamoeba fragilis infection in children, a retrospective study.

INTRODUCTION: Dientamoeba fragilis infection in children is common, and its incidence has increased since the introduction of more sensitive molecular techniques. There is no consensus on the optimal treatment. Current medical practice in the Netherlands is to treat symptomatic children with clioquinol or metronidazole. This study attempts to obtain more information about the clinical picture of D. fragilis infection in children and to evaluate responses to both antiparasitic drugs. METHODS: Children <18 years of age with a positive stool polymerase chain reaction test for D. fragilis infection were retrospectively evaluated. Clinical data and effectiveness of treatment were analyzed by examining patient's hospital records from the Medical Centre Leeuwarden by repeated analysis of stool samples by the Centre for Infectious Diseases in Friesland. RESULTS: We analyzed 238 patients with an average age of 8.5 years (±4.2 years). Most patients were symptomatic (95.8%) and presented with abdominal pain (72.7%), loose stools (32.8%) and hard stools (24.8%). Coinfection with other gastrointestinal pathogens was present in 29 patients (12.2%). A higher incidence of infection was found in the winter. Clioquinol had a higher clinical success rate than metronidazole (74.7% versus 55.2%, P = 0.047). CONCLUSION: These results suggest that clioquinol could be more effective than metronidazole in alleviating symptoms of D. fragilis infection in children, but double-blind prospective placebo-controlled studies should be performed before final conclusions can be made.

Specific increase in local IL-17 production during recovery from primary RSV bronchiolitis.

Although Respiratory syncytial virus (RSV) bronchiolitis is the most important cause of hospital admission for infants during the winter season, the pathogenesis is largely unknown. Interleukin-17 (IL-17) concentrations were studied in nasopharyngeal aspirates from 21 non-ventilated and 17 ventilated infants admitted to hospital with RSV bronchiolitis at time of admission and discharge from the hospital. On admission, nasopharyngeal concentrations of most cytokines and chemokines were lower in non-ventilated infants than in ventilated infants, reaching statistical significance for Eotaxin, IL-1α, and IL-6. During course of disease, nasopharyngeal concentrations of most cytokines and chemokines decreased, reaching statistical significance for IL-6 and IP-10. However, nasopharyngeal IL-17 concentrations were higher at discharge than at admission in children with non-ventilated RSV disease (209-101 pg/ml, P = 0.008), a response pattern not observed in ventilated RSV patients nor for other cytokines or chemokines. It is speculated that local IL-17 production may be involved during convalescence from RSV bronchiolitis in non-ventilated patients by facilitating innate and adaptive antiviral immune responses. The role of IL-17 in the pathogenesis of RSV bronchiolitis is to be explored further.

IL1RL1 gene variants and nasopharyngeal IL1RL-a levels are associated with severe RSV bronchiolitis: a multicenter cohort study.

BACKGROUND: Targets for intervention are required for respiratory syncytial virus (RSV) bronchiolitis, a common disease during infancy for which no effective treatment exists. Clinical and genetic studies indicate that IL1RL1 plays an important role in the development and exacerbations of asthma. Human IL1RL1 encodes three isoforms, including soluble IL1RL1-a, that can influence IL33 signalling by modifying inflammatory responses to epithelial damage. We hypothesized that IL1RL1 gene variants and soluble IL1RL1-a are associated with severe RSV bronchiolitis. METHODOLOGY/PRINCIPAL FINDINGS: We studied the association between RSV and 3 selected IL1RL1 single-nucleotide polymorphisms rs1921622, rs11685480 or rs1420101 in 81 ventilated and 384 non-ventilated children under 1 year of age hospitalized with primary RSV bronchiolitis in comparison to 930 healthy controls. Severe RSV infection was defined by need for mechanical ventilation. Furthermore, we examined soluble IL1RL1-a concentration in nasopharyngeal aspirates from children hospitalized with primary RSV bronchiolitis. An association between SNP rs1921622 and disease severity was found at the allele and genotype level (p = 0.011 and p = 0.040, respectively). In hospitalized non-ventilated patients, RSV bronchiolitis was not associated with IL1RL1 genotypes. Median concentrations of soluble IL1RL1-a in nasopharyngeal aspirates were >20-fold higher in ventilated infants when compared to non-ventilated infants with RSV (median [and quartiles] 9,357 [936-15,528] pg/ml vs. 405 [112-1,193] pg/ml respectively; p<0.001). CONCLUSIONS: We found a genetic link between rs1921622 IL1RL1 polymorphism and disease severity in RSV bronchiolitis. The potential biological role of IL1RL1 in the pathogenesis of severe RSV bronchiolitis was further supported by high local concentrations of IL1RL1 in children with most severe disease. We speculate that IL1RL1a modifies epithelial damage mediated inflammatory responses during RSV bronchiolitis and thus may serve as a novel target for intervention to control disease severity.

Respiratory syncytial virus bronchiolitis: prevention and treatment.

BACKGROUND: Acute respiratory illness due to respiratory syncytial virus is one of the most common causes of hospitalization in very young children worldwide. The virus was discovered half a century ago, yet the underlying mechanisms of the disease are not fully understood and treatment remains supportive. METHODS: This review article discusses therapeutic and preventive strategies, past, present and future, in the battle against respiratory syncytial virus. CONCLUSION: Prevention of severe respiratory syncytial virus infection in high-risk children can be achieved by the administration of specific monoclonal antibodies. Current issues include the management of respiratory syncytial virus infection in those with underlying immunological disease, the prevention of long-term airway morbidity and the development of innovative vaccines.