Eun Song

Epidemiology of respiratory syncytial virus infection in infants born at less than thirty-five weeks of gestational age.

Background: The aims of this study were to observe the respiratory syncytial virus (RSV) hospitalization rate and to identify the risk factors for hospitalization for RSV infection among infants in Korea born at <35 weeks of gestational age and who had not previously received palivizumab. Methods: We conducted a study over a 2.5-year period (between April 2007 and September 2009) that included premature infants (<35 weeks of gestational age) who underwent follow-up during 1 year after discharge from the neonatal intensive care unit. Demographic information was collected for each subject at baseline, and the reasons for hospitalization were obtained during the 1-year follow-up period. Results: The study population included 1022 subjects who completed follow-up interviews. Eight hundred seventeen infants were included in analysis for RSV hospitalization. Excluded from the study were 167 subjects with chronic lung disease who had received palivizumab prophylaxis and 38 subjects who were not tested for RSV. The overall incidence of RSV hospitalization in the group that did not receive palivizumab was 4.5% (37 of 817 patients). Independent risk factors associated with RSV hospitalization were multiple gestation (P = 0.022) and longer duration of mechanical ventilation in the neonatal intensive care unit (P = 0.039). Conclusion: This study showed the epidemiology and risk factors of RSV hospitalization in preterm infants in Korea. RSV infection was one of the main causes of hospitalization after discharge from the neonatal intensive care unit in patients born at <35 weeks of gestational age.

Comparison of Oral Ibuprofen and Intravenous Indomethacin for the Treatment of Patent Ductus Arteriosus in Extremely Low Birth Weight Infants

OBJECTIVE There are few published reports concerning the efficacy of oral ibuprofen for the treatment of patent ductus arteriosus (PDA) in extremely low birth weight (ELBW) infants. Oral ibuprofen was compared to intravenous indomethacin regarding efficacy and safety in the treatment of PDA in infants weighting less than 1,000g at birth. METHOD This was a retrospective study in a single center. Data on ELBW infants who had an echocardiographically confirmed PDA were collected. The infants were treated with either intravenous indomethacin or oral ibuprofen. Rate of ductal closure, need for additional treatment, drug-related side effects or complications, and mortality were compared between the two treatment groups. RESULT 26 infants who received indomethacin and 22 infants who received ibuprofen were studied. The overall rate of ductal closure was similar between the two treatments: it occurred in 23 of 26 infants (88.5%) treated with indomethacin, and in 18 of 22 infants (81.8%) treated with ibuprofen (p=0.40). The rate of surgical ligation (11.5% versus 18.2%; p=0.40) did not differ significantly between the two treatment groups. No significant difference was found in post-treatment serum creatinine concentrations between the two groups. There were no significant differences regarding additional side effects or complications. CONCLUSION In ELBW infants, oral ibuprofen is as efficacious as intravenous indomethacin for the treatment of PDA. There were no differences between the two drugs with respect to safety. Oral ibuprofen could be used as an alternative agent for the treatment of PDA in ELBW infants.

Multilocus sequence typing for the analysis of clonality among Candida albicans strains from a neonatal intensive care unit

Nosocomial Candida albicans infections are a significant problem in neonatal intensive care units (NICUs). We investigated the clonality of C. albicans isolates recovered over an 8-year period from neonates at a NICU. We also validated multilocus sequence typing (MLST) compared with pulsed-field gel electrophoresis (PFGE) for the genotyping of C. albicans strains from the same NICU. A total of 43 clinical isolates (10 blood, 19 urine, and 14 other) were obtained from 43 neonates between 2005 and 2012. Clonal strains were defined as the isolation of two or more strains with identical or similar genotypes as determined with both MLST and PFGE. Using MLST, the 43 isolates yielded 25 diploid sequence types (DSTs) and 10 DSTs were shared by 28 isolates (65.1%). Among the 28 isolates sharing 10 DSTs, isolates from each of seven DSTs had the same or similar PFGE pattern. In addition, two sets of isolates that differed by MLST at only one locus had the same or similar PFGE pattern. Overall, when the MLST and PFGE results were combined, 22 isolates (51.2%) shared eight genotypes, suggesting clonal strains. Strains from each of seven genotypes (total, 19 isolates) were isolated among the 22 clonal strains within a 6-month period, whereas three strains of one genotype were obtained over a 3-year interval. Our findings suggest that horizontal transmission of C. albicans may occur more frequently than vertical transmission among NICU patients and that MLST appears to be a useful method for genotyping C. albicans strains isolated from NICU patients.

Expression of SAP5 and SAP9 in Candida albicans biofilms: comparison of bloodstream isolates with isolates from other sources

Secreted aspartic proteases (Sap), encoded by a family of 10 SAP genes, are key virulence determinants in Candida albicans. Although biofilm-associated bloodstream infections (BSIs) are frequently caused by C. albicans, SAP gene expression in C. albicans biofilms formed by BSI isolates has not been evaluated. We compared the expression of two SAP genes, SAP5 and SAP9, in C. albicans biofilms formed by BSI isolates with those formed by isolates from other body sites. Sixty-three C. albicans isolates were analyzed, comprising 35 BSI isolates and 28 from other sites. A denture-strip biofilm model was used, and expression of the two SAP genes was quantified by real-time RT-PCR during planktonic or biofilm growth. Mean SAP5 expression levels of the BSI isolates were 3.59-fold and 3.86-fold higher in 24-h and 48-h biofilms, respectively, than in planktonic cells. These results did not differ from those for isolates from other sites (2.71-fold and 2.8-fold for 24-h and 48-h biofilms, respectively). By contrast, mean SAP9 expression during biofilm formation was higher in BSI isolates (2.89-fold and 3.29-fold at 24 and 48 h, respectively) than in isolates from other sites (1.27-fold and 1.32-fold at 24 and 48 h, respectively; both, P < 0.001). These results show, for the first time, that both SAP5 and SAP9 are upregulated in C. albicans biofilms formed by BSI isolates, and that BSI isolates may have a greater capacity to express SAP9 under biofilm conditions than isolates from other sites.

Bloody nipple discharge in an infant

Although milky nipple discharge appears frequently in infants, bloody nipple discharge is a very rare finding. We experienced a 4-month-old, breast-fed infant who showed bilateral bloody nipple discharge with no signs of infection, engorgement, or hypertrophy. The infants hormonal examination and coagulation tests were normal, and an ultrasound examination revealed mammary duct ectasia. The symptoms resolved spontaneously within 6 weeks without any specific treatment, except that we advised the mother to refrain from taking herbal medicine. Since no such case has been previously reported in Korea, we present this case with a brief review of the literature.

In Vitro Fluconazole and Voriconazole Susceptibilities of Candida Bloodstream Isolates in Korea: Use of the CLSI and EUCAST Epidemiological Cutoff Values

Background At present, the clinical breakpoints (CBPs) of both fluconazole and voriconazole are available only for 3 common Candida species in the Clinical and Laboratory Standards Institute (CLSI) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) methods. Epidemiological cutoff values (ECVs) were recently applied to both methods to detect the emergence of acquired resistance (i.e., non-wild-type isolates) among 5 common Candida species. Methods We performed a nationwide study to determine the fluconazole and voriconazole susceptibility of Candida bloodstream isolates (BSIs) using both the CLSI and EUCAST methods. A total of 423 BSIs of 5 Candida species were collected from 8 hospitals. The azole susceptibilities were assessed on the basis of the species-specific CBPs and ECVs. Results Of the 341 BSIs of 3 common Candida species (i.e., C. albicans, C. tropicalis, and C. parapsilosis), 0.3% and 0.9%, 0.0% and 1.5% of isolates were categorized as fluconazole and voriconazole resistant according to the CLSI and EUCAST CBPs, respectively. Of 423 total BSIs, 1.4% and 2.6% had fluconazole minimum inhibitory concentrations (MICs) exceeding the ECVs according to the CLSI and EUCAST, respectively; 1.0% and 2.1% had voriconazole MICs exceeding the ECVs according to the CLSI and EUCAST, respectively. Categorical agreement between the methods using ECVs was 98.3% for fluconazole and 98.3% for voriconazole. Conclusions The EUCAST and CLSI methods using ECVs provide highly concordant results. Moreover, non-wild-type isolates with possibly acquired azole resistance were rare among the BSIs of 5 common Candida species in Korea.

Recent Changes in the Incidence of Bronchopulmonary Dysplasia among Very-Low-Birth-Weight Infants in Korea.

We investigated the incidence of bronchopulmonary dysplasia (BPD) in very-low-birth-weight (VLBW) infants in Korea using the Korean Neonatal Network (KNN) data. In total, 2,386 VLBW infants born from January 2013 to June 2014 were prospectively registered. BPD was defined as supplemental oxygen or positive pressure support at 36 weeks postmenstrual age (PMA). The overall incidence of BPD was 28.9%, and the overall mortality rate in the neonatal intensive care units (NICUs) was 11.9%. To investigate recent changes in the incidence of BPD among VLBW infants, we compared the BPD rate in the present study with the latest nationwide retrospective survey conducted between 2007 and 2008. For comparison, we selected infants (23-31 weeks of gestation) (n=1,990) to adjust for the same conditions with the previous survey in 2007-2008 (n=3,841). Among the limited data on VLBW infants (23-31 weeks of gestation), the incidence of BPD increased by 85% (from 17.8% to 33.0%) and the mortality rate in the NICU decreased by 31.4% (from 18.8% to 12.9%) compared to those in the study conducted in 2007-2008. The current trend of increase in the incidence of BPD among infants can be attributed to the increase in the survival rate of VLBW infants.

Radiodensity on serial chest X-rays for the diagnosis of foreign body aspiration in children

ObjectivesTo evaluate the utility of measuring lung radiodensity from chest X-ray for the diagnosis of foreign body aspirationMethodsRecords of 59 children with foreign body aspiration were retrospectively reviewed. Lung radiodensity and radiodensity ratio (right/left lung radio density) before and after foreign body removal were measured. Radiodensity was calculated as the relative score compared with the tenth thoracic vertebra body (100 points) and the background (0 point). The change of radiodensity ratio (difference in radiodensity ratio of the second X-ray from that of first X-ray) was compared between 22 patients (foreign body group) and 22 normal subjects (control group).ResultsIn the group of foreign body in the left bronchus, the mean (SD) radiodensity of the left lung [53.5 (12.8)] was lower than that of the right lung [60.8 (7.7), P<0.01] and it increased after foreign body removal [60.0 (6.9), P=0.02]. The radiodensity ratio decreased from 1.20 (0.30) to 0.96 (0.09) (P<0.01) after foreign body removal. In the group with a foreign body in the right bronchus, the radiodensity of the right lung [51.8 (12.8)] was lower than that of left lung [62.0 (11.7), P=0.03], and it also increased after foreign body removal [58.4 (9.6), P=0.03]. The change of radiodensity ratio in the foreign body group [15.7 (17.8)%] was higher than the control group [5.4 (4.3)%, P=0.01] and the cutoff value was 7.5%.ConclusionRadiodensity from chest X-ray could be a useful tool for diagnosing foreign body aspiration in children.

Transient complete atrioventricular block in a preterm neonate with congenital myotonic dystrophy: case report.

Congenital myotonic dystrophy (CMD) is an inherited neuromuscular disorder with cardiac rhythm abnormalities that may occur as a child grows. No report has described complete atrioventricular (AV) block detected in a neonate with CMD. We report a floppy infant of 31+4 weeks gestation with complete AV block at birth, who was diagnosed with CMD by Southern analysis. She recovered from complete AV block 32 hr after temporary transcutaneous pacing was applied. To the best our knowledge, this is the first recorded case of a complete AV block accompanied by CMD during the neonatal period. When a newborn has a complete AV block, the physician should consider the possibility of the CMD and conduct a careful physical examination. Graphical Abstract

Procalcitonin Levels in Patients with Complete and Incomplete Kawasaki Disease

Incomplete Kawasaki disease (iKD) is considered to be a less complete form of Kawasaki disease (cKD), and several differences in the laboratory presentations of iKD and cKD have been noted. We investigated serum procalcitonin levels in patients with iKD, cKD, and other febrile diseases (a control group). Seventy-seven patients with cKD, 24 with iKD, and 41 controls admitted to our hospital from November 2009 to November 2011 were enrolled in the present study. We obtained four measurements of serum procalcitonin levels and those of other inflammatory markers from each patient. Samples were taken for analysis on the day of diagnosis (thus before treatment commenced; D0) and 2 (D2), 14 (D14), and 56 days (D56) after intravenous immunoglobulin infusion. We obtained control group data at D0. The mean D0 serum procalcitonin levels of cKD patients (0.71 ± 1.36 ng/mL) and controls (0.67 ± 1.06 ng/mL) were significantly higher than those of iKD patients (0.26 ± 0.26 ng/mL) (P = 0.014 and P = 0.041, resp.). No significant difference in mean procalcitonin level was evident among groups at any subsequent time. In conclusion, the serum procalcitonin level of patients with acute-stage cKD was significantly higher than that of iKD patients.