Introduction: Respiratory infection in particular community acquired pneumonia (CAP) in children is a major disease that ranks high in outpatient and inpatient cases. The causes of CAP vary depending on the individual susceptibility, epidemiological characteristics of the community, and season. We performed this study to establish nationwide survillance network system and identify the causative agents for CAP and antibiotics resistance in Korean children with CAP.. Methods: The monitoring network was composed of the 28 secondary and tertiary medical institutions. Upper and lower respiratory samples were assayed using culture or Polymerase chaini reaction (PCR) from Aug 2018 to May 2020. Results: A total of 1023 cases were registered in patients with CAP, and 264 cases (25.8%) were isolated by culture, S. aureus 131 cases (12.8%), S. pneumoniae 92 cases (9%), H. influenzae 20 cases (2%). PCR of atypical pneumonia pathogen revealed 422 cases of M. pneumoniae (41.3%). Respiratory virus showed positive rates in 65.7% by multiplex PCR test and of them, human rhinovirus was most highest with 312 cases (30.5%). The proportion of mixed infection was 49.2%. The rate of antibiotics resistance showed similar results as previous reports. Conclusion: It will identify the pathogens that cause respiratory infections, and analyze the current status of antibiotic resistance to provide scientific evidence for management policies of domestic respiratory infection. Also, in preparation for the new epidemic, including COVID19, monitoring of respiratory infections in children and adolescents, has become more important, and research should be continuously conducted in the future.

Background: Phthalates can cause respiratory and immunological disorders. However, little is known about the role of serum periostin and YKL-40 levels in mediating the effects of phthalates. We investigated the mediating role of these biomarkers in the relationship between phthalates and airway dysfunction. Methods: A total of 487 children (aged 10 to 12 years-old) were examined. Four high-molecular-weight phthalate (HMWP) [Σ4HMWP] metabolites and 3 low-molecular-weight phthalate (LMWP) [Σ3LMWP] metabolites in urine samples were measured. Serum periostin and YKL-40 levels were measured. Airway function was measured using impulse oscillometry. A mediation model was used to quantify the mediating effects of periostin and YKL-40 on airway dysfunction. Results: After adjustment for height, gender, BMI z-score, aeroallergen sensitization, secondary smoking, and vitamin D level, the level of urinary Σ3LMWP metabolites was significantly associated with respiratory system resistance at 5 Hz (Rrs5; adjusted β: 0.020, 95% CI: 0.005 to 0.034; P = .010). The levels of urinary Σ4HMWP and Σ3LMWP metabolites were significantly associated with periostin level, but not with YKL-40 level. In addition, the periostin level was associated with Rrs5 (adjusted β: 0.048, 95% CI: 0.015 to 0.081; P = .005) and Rrs20-5 (adjusted β: 0.040, 95% CI: 0.011 to 0.069; P =.007). Serum periostin level had a significant effect in mediating the relationship between Σ3LMWP and Rrs5 (13.9%, 95% CI: 10.7 to 77.0; P < .001). Conclusion: Exposure to LMWPs was significantly associated with airway dysfunction, and this effect was partially attributable to increased serum periostin level.

Background The association between dyslipidemia and atopic dermatitis in children is unclear. This study investigated the association between dyslipidemia and atopic dermatitis in children by analysis of disease onset, risk factors, and disease severity. Methods Subset I examined 7 year-old children in elementary school (n = 248) and Subset II was a retrospective long-term follow-up hospital based-study (n = 52,725) conducted from 1986 to 2016 that used propensity score matching. In the Subset I Study, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides (TG) were determined, and the severity of atopic dermatitis was determined using SCORing Atopic Dermatitis (SCORAD). In the Subset II Study, the time of atopic dermatitis onset was determined for asymptomatic subjects whose TC levels were below or above 170 mg/dL. Results Our Subset I Study indicated that children with atopic dermatitis (n = 69, 27.8%) had significantly higher levels of TC and TG, and that disease severity had significant associations with high levels of TC and TG, and a low level of HDL-C. Our Subset II Study (1,722 with high TC and 6,735 with normal TC after propensity score matching) indicated the high TC group had a greater hazard ratio (HR) for the onset of atopic dermatitis (consensus-based HR: 2.47; 95% CI: 1.23, 5.06, P = 0.012) during 5 years. Conclusion An abnormal blood lipid profile in children is associated with the presence and severity of atopic dermatitis. The risk of atopic dermatitis onset was significantly greater with high levels of TC.