Clinical difference between single infection and coinfection with respiratory virus: The 2014 single-center study

PURPOSE: We investigated the clinical difference between single infection and coinfection with respiratory virus in hospitalized children with acute respiratory tract infections. METHODS: We reviewed 727 patients who were admitted with the diagnosis of acute respiratory infection at the Department of Pediatrics, Bundang Jesaeng Hospital between January and December of 2014. Diagnoses were made using the multiplex reverse transcriptase polymerase chain reaction (RT-PCR) assay targeting 16 viruses in nasopharyngeal swabs. Subjects were classified as the single virus infection and coinfection groups. RESULTS: A total of 439 patients were enrolled; 359 (77.2%) under 24 months. Single virus was detected in 279 (63.6%). Coinfection with multiple virus was detected in 160 (36.4%): 126 (28.7%) with 2 viruses, 30 (6.8%), and 4 (0.9%) with 3 to 4 viruses. Viral coinfection was detected in 28 samples (17.5%), with respiratory syncytial virus (RSV) A and rhinovirus being the most dominating combination. There were no clinical differences between the single infection and coinfection groups, except sputum and the frequency of high RSV load. Sputum was significantly more frequent in the coinfection group (P=0.043), and the frequency of high RSV load was significantly higher in the single infection group (P=0.029). Disease severity (high fever, the duration of fever [≥5 days], and the length of hospital stay [≥5 days], O₂ therapy) did not differ significantly between both groups. RSV was a frequent virus of single infection during winter. Coinfection was most common in winter. CONCLUSION: There were no clinical differences between single infection and coinfection, except sputum and the frequency of high RSV load.

Factors associated with obesity of acute bronchiolitis in infants: association of obesity with disease severity

PURPOSE: Both under-nutrition and obesity may be associated with severity of viral infection. We investigated the association of obesity with clinical factors and the severity of acute bronchiolitis in infants. METHODS: We reviewed 740 infants younger than 1 year of age who were admitted with the first episode of acute bronchiolitis between 2010 and 2013. Subjects were classified into 3 groups according to the weight-for-length Z-score. RESULTS: Younger age (3.6+/-2.6 months) was more frequent in the obesity group (P<0.001). Infants aged < or =6 months (90%) dominantly included in the obesity group. Logistic regression showed that age (younger than 3 months) was independently associated with the overweight and obesity groups with acute bronchiolitis in infants (odds ratio [OR], 1.77; P=0.001 for overweight; OR, 4.67; P<0.001 for obesity). Moreover, the obesity group was associated with an increased risk of chest retraction, hypoxia, respiratory syncytial virus detection, length of stay (more than 5 days), and need for oxygen supplement. These factors tended to increase from the overweight group toward the obesity group. CONCLUSION: Younger than 3 months of age was a risk factor for developing worse clinical course in overweight and obesity groups with acute bronchiolitis in infants. Careful attention should be paid to the clinical course of younger obese infants with acute bronchiolitis.

Clinical characteristics of primary spontaneous pneumothorax in adolescents: factors for recurrence

PURPOSE: The aim of this study was to investigate the clinical characteristics of primary spontaneous pneumothorax (PSP) in adolescents and identify risk factors for the recurrence of PSP. METHODS: A total of 292 patients diagnosed with PSP from January 1998 to December 2011 were retrospectively studied. Clinical data on demographics, diagnostic imaging, therapies, and risk factors of recurrence were collected and analyzed. RESULTS: The sex ratio of 292 patients was 19.8:1 (male:female), and the average age of the patients was 17.0 years. The average body mass index of the patients was 18.8 kg/m2. The most common presenting symptom was chest pain. There was no seasonal variation in the incidence of PSP. Thirty patients (10.2%) had a history of smoking. The most common location of PSP was the left side. Out of 249 patients, 169 (67.9%) had cysts (blebs/bullae). Fifty-four patients (18.5%) received oxygen therapy, 3 patients (1%) needle aspiration, 119 patients (40.8%) closed tube drainage, and 116 patients (39.7%) surgery. The recurrence rate was 38.6%. Smoking was associated with the size of pneumothorax (P=0.002). Also, the size of pneumothorax and surgery was associated with recurrence (P=0.040 and P=0.004). However, previously reported risk factors for recurrence were not identified in our patients. CONCLUSION: Pediatric PSP occurred mainly in males in late adolescence with normal body mass index. No significant risk factors were related to recurrence of PSP in our study.