The purpose of this study was to evaluate the viral frequency, seasonality, and clinical and demographic features of patients hospitalized with acute bronchiolitis. A cross-sectional, descriptive study was performed in 316 infants younger than 2 years of age who were hospitalized for acute viral bronchiolitis. Respiratory tract infection agents were investigated with polymerase chain reaction (PCR). A total of 316 infants were included in this study. Of the 316 infants, at least one respiratory tract pathogen was detected in 75% (237/316). Respiratory syncytial virus (RSV) was the most common virus identified in 127 infants (40.1%) followed by rhinovirus (n = 78, 24.6%). In this study, where viral agents were determined via PCR in patients who were followed-up due to the diagnosis of acute bronchiolitis, RSV was detected as the most common agent, as in other studies. In almost half of the RSV-positive patients, RSV was accompanied by a second or third agent.

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Kurugöl Z, Gökçe Ş. Outbreak of varicella in preschool children despite one-dose vaccination. Turk J Pediatr 2018; 60: 56-62. In Turkey, a single-dose varicella vaccine was introduced into the National Immunization Program in 2013. Before this implementation, varicella vaccine had been available in the private sector since 2000. However, varicella outbreaks continued to occur in preschools and elementary schools. We investigated a varicella outbreak to estimate the effectiveness of 1-dose varicella vaccine and to evaluate potential risk factors for breakthrough disease. This study was carried out during a varicella outbreak in 3 preschools in İzmir, Turkey, in April 2016. Using questionnaires, data including children`s medical and vaccination histories were collected from their parents. Attack rates in vaccinated and unvaccinated children were calculated and the analyses of vaccine effectiveness and of risk factors for breakthrough disease were conducted. A total of 124 children were enrolled in the study. Of the 124 children, 77 (62%) had received 1-dose varicella vaccine before the outbreak. Varicella developed in 34 of 124 children during the outbreak, and 18 of them (53%) had breakthrough varicella. The attack rate was 23.4% among vaccinated children and 34% among unvaccinated children. The effectiveness of single-dose varicella vaccine was 33.6% against varicella disease of any severity and 82.5% against moderate or severe varicella. Children vaccinated 5 or more years before the outbreak had 3.5 times the risk of disease than those who had been vaccinated more recently (OR 3.5 [95% CI, 1.08-11.5]); p= 0.046). Age at vaccination ( < 15 months vs.≥15 months) and the brands of varicella vaccine were not associated with the increased risk of breakthrough varicella. Our study suggests that one-dose of varicella vaccine is not sufficient to prevent school outbreaks. A 2-dose varicella vaccination program may help to prevent varicella outbreaks and achieve effective control of the disease.

Bordetella pertussis infection is common in young infants hospitalized for acute bronchiolitis, mostly as co-infection with respiratory viruses. The clinical features of pertussis in the infants are not characteristic. Viral bronchiolitis and pertussis cases could not be differentiated by clinical findings. Co-infection with pertussis did not affect the clinical outcome in infants hospitalized with acute bronchiolitis.

Objectives: Respiratory syncytial virus (RSV) is a major cause of respiratory infections in infants and children. The aim of this study was to evaluate clinical significance of respiratory infections as single pathogen RSV, respiratory viruses with RSV and those with bronchiolitis caused by other respiratory viruses. Methods: A total of 316 throat swabs were collected from children diagnosed with acute bronchiolitis. Real-time polymerase chain reaction was used to identify the viruses in the samples. The subjects were divided into three groups: single pathogen RSV, agents with RSV and agents without RSV. Binary logistic regression analysis was used to evaluate the corelation between single and multiple RSV infection group and infections without RSV group for parameters including age, wheezing, supplemental oxygen therapy. Results: The overall positivity for viruses in the study was found to be 75% with a co-infection rate of 34.2%. Compared to children with RSV alone, children with any other agents accompanying RSV, were not very likely to have fever, wheezing or supplemental oxygen therapy. Conclusions:The findings of our study suggest that RSV still represents a large burden of bronchiolitis since it is associated with the hospitalization of children, particularly those less than six months old. We can not foresee the clinical presentation of specific agent or agents in connection to being with or without RSV in infants with any level of bronchiolitis. The study agrees with the concept that co infections with or without RSV do not increase the severity of the disease.