• Clinical and Experimental Pediatrics
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• v.51 no.7
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• pp.729-735
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• 2008

Purpose : Chlamydia trachomatis is one of the most common sexually transmitted diseases and is also a cause of pneumonia in infants. Respiratory infections by respiratory viruses are also common for infants. The objectives of this study were to identify the clinical manifestations and to determine the prevalence of C. trachomatis respiratory infections and coinfections by respiratory viruses in infants younger than 6 months of age. Methods : For this study, we enrolled 6 months or younger infants who were admitted to the Dankook University Hospital between January 2002 and July 2007, with respiratory symptoms. Nasopharyngeal aspirates or throat swabs were collected within s d of hospitalization and C. trachomatis was detected using polymerase chain reaction (PCR). Patients who tested positive underwent multiplex PCR for respiratory viruses. Results : A total of 690 patients underwent chlamydial PCR testing and 36 (5.2%) had positive results. Of the 36, 28 (78%) were male; 30 were vaginally delivered. From the 36 patients positive for C. trachomatis, 26 underwent multiplex respiratory viral PCR; 12 were coinfected with viruses. Respiratory syncytial virus (RSV) was the most frequent pathogen that was detected in 6 patients. Increased C-reactive protein and fever were significant in patients coinfected with respiratory viruses. Conclusion : C. trachomatis can infected in infants delivered by cesarean section as well as in 6 months old or younger infants. Infant with C. trachomatis respiratory infections can also be coinfected with respiratory infection also coinfected with respiratory viruses. Further studies are needed to better understand the prevalence rates of the this infection and its coinfection rate with respiratory viruses.

• Clinical and Experimental Pediatrics
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• v.49 no.11
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• pp.1186-1193
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• 2006

Purpose : Enterovirus infection is a type of viral infection that occurs relatively frequently in children during summer. It has clinical symptoms of non-specific fever, aseptic encephalomeningitis, gastrointestinal diseases, skin rash and, hand-foot-mouth disease. However, it can also occcaisionally, result in fatal symptoms like myocarditis, epicardial inflammation, transverse myelitis, quadriplegia and etc. There have been epidemic enterovirus studies, but not in the Chungnam area. Therefore, we undertook this study in order to comprehend the cause viruses in this area. Methods: We enlisted 157 children hospitalized with enteroviral infections at Soonchunhyang University hospital in Cheonan between May and August 2005. Cerebrospinal fluids or feces were collected during the acute phase after hospitalization, and observed the cytopathic effects caused by enterovirus and using reverse transcription polymerase chain reaction (RT-PCR). Results : The number of children hospitalized due to possible enteroviral infection during the period of study was 157. The number of children who tested positive with the reverse transcription polymerase chain reaction totalled 32 cases (20.4 percent). Among the children with entroviral diseases, 20 were male and 12 were female, thus the sex ratio of male to female was 1.67:1. Their clinical symptoms included fever most frequently (93.7 percent), was followed by headaches (90.0 percent), meningeal irritation signs (65.0 percent), and abdominal pain (30.0 percent). As for the type of isolated enterovirus, there were 17 cases of echovirus 18 and 6 cases of coxsackievirus B5. Furthermore, there were 2 cases of echovirus 9, 1 case of coxsackievirus A6 and coxsackievirus B3, respectively. But 5 cases were not determined by genotype. Conclusion : Echovirus 18 is circulating in Korea. We reported on identified enteroviruses, including echovirus 18, using RT-PCR in the Chungnam area during the summer of 2005.

• Clinical and Experimental Pediatrics
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• v.49 no.4
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• pp.401-409
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• 2006

Purpose : Human metapneumovirus(hMPV) is a respiratory viral pathogen that causes a wide spectrum of illnesses, ranging from asymptomatic infection to severe bronchiolitis. The virus has been identified world widely, but so far it has not been published in Korea. Methods : We obtained clinical samples by nasopharyngeal aspiration from 218 children hospitalized due to acute lower respiratory tract infections at Soonchunhyang University Hospital in Cheonan from October, 2004 to April, 2005. We designed specific primers from conserved region of fusion glycoprotein of hMPV. Total RNA was extracted and RT-PCR was performed, and single specific 423 bp product was obtained. The PCR product was confirmed to be fusion glycoprotein RNA by sequencing. Results : We detected hMPV in 15(6.9 percent) of the 218 hospitalized children. The infected children comprised nine boys and six girls; their mean age was 2.8 years(5 mo-12 yrs) and they were diagnosed with pneumonia(60 percent), bronchiolitis(33.3 percent), croup(6.6 percent). The number of cases of detected hMPV in Korea increased dramatically during the period from March to May 2005. Conclusion : hMPV is circulating in Korean children and is associated with respiratory tract infection. Additional studies are required to define the epidemiology and the extent of diseases in the general population caused by hMPV.

• Clinical and Experimental Pediatrics
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• v.52 no.3
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• pp.330-338
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• 2009

Purpose : The causes of acute lower respiratory tract infection (ALRTI) are mostly attributable to viral infection, including respiratory syncytial virus (RSV), parainfluenza virus (PIV), influenza virus A/B (IFV A/B), or adenovirus (ADV). Several Korean studies reported human metapneumovirus (hMPV) as a common pathogen of ALRTI. However, studies on seasonal distribution and clinical differences relative to other viruses are insufficient, prompting us to perform this study. Methods : From November 2006 to October 2007, we tested nasopharyngeal aspiration specimens in children hospitalized with ALRTI with the multiplex reverse transcriptase-polymerase chain reaction to identify 6 kinds of common pathogen (hMPV, RSV, PIV, IFV A/B, and ADV). We analyzed positive rates and clinical features by respiratory chart review. Results : We detected 38 (8.4%) hMPV-positive cases out of 193 (41.8%) virus-positive specimens among 462 patients. HMPV infection prevailed from March to June with incidence peaking in April. HMPV-positive patients were aged 15 years (76.3%), and the ratio of boys to girls was 1.2:1. The median age was 27 months. HMPV primarily caused pneumonia (76.3 %) (P=0.018). Average hospitalization of HMPV-associated ALRTI patients was 5.8 days. In addition, they showed parahilar peribronchial infiltration (100%) on chest X-ray, normal white blood cell count (73.7%), and negative C-reactive protein (86.8 %) (P>0.05). All hMPV-positive patients recovered without complication. Conclusion : HMPV is a common pathogen of ALRTI in Korean children, especially in 1-5 year olds, from March to May. Immunocompetent children diagnosed with hMPV-associated ALRTI may have a good prognosis.

• Pediatric Infection and Vaccine
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• v.8 no.1
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• pp.94-100
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• 2001

Purpose : Enterovirus is a common cause of aseptic meningitis and nonspecific febrile illness in young children. During the summer and fall months, enterovirus-infected young children are frequently admitted and evaluated to rule out bacterial sepsis and/or meningitis. The purpose of this study was to evaluate the relationship between nonpolio enterovirus infection and febrile illness in infants under 3 months of age during the summer, fall months by using a stool culture to identify the presence of enterovirus. Methods : Patients included febrile infants under 3 months of age admitted to Masan Fatima Hospital for sepsis evaluation from May 1999 to September 1999. Cultures were performed from stool and Cerebrospinal fluid samples and then were tested for enterovirus infection. Viral isolation and serotype identification were performed by cell culture and immunofluorescent testing. Enteroviruses not typed by immunofluorescent testing were confirmed by reverse transcription-polymerase chain reaction. Results : A total of 44 febrile infants were enrolled; of those, 20(45%) were positive for enterovirus. Two enterovirus culture-positive infants had concomitant urinary tract infection and one had Kawasaki disease. All infants infected with an enterovirus recovered without complications. Serotype of 20 enteroviruses were isolated from stool, 3 of echovirus type 9, 1 of echovirus type 11, 1 Coxsachievirus type B4, 15 of untyped enteroviruses. One untyped enterovirus was isolated in the CSF. Conclusion : Nonpolio enterovirus infections are associated with nonspecific febrile illnesses in infants under 3 months of age.

• Pediatric Infection and Vaccine
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• v.11 no.1
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• pp.73-80
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• 2004

Purpose : The serial clinical findings, biochemical results, and serological hepatitis B virus(HBV) markers in Korean children with chronic HBV infection were analyzed to determine the relationships among these factors. Methods : Ninety children have been chosen from those who have visited to the Department of Pediatrics at St. Vincent's Hospital in The Catholic University of Korea from July 1st, 1995 to June 30th, 2000. The sample patients were followed up for over six months. HBV markers and liver function tests were all performed. Results : All children were asymptomatic at presentation. Eighty-three percent of the children had a history of chronic HBV infection in their families. Eighty-one percent were HBeAg positive, 16% were anti-HBe positive, while 3% were all HBeAg and anti-HBe negative. The prevalence of HBeAg among three age groups : 0~5; 6~10; and 11~15 year-old was 90%, 96% and 61% respectively. The prevalence of HBeAg in less than 10 year-old group was significantly higher than 11~15 year-old group(P=0.001). Serum ALT levels were within 40 IU/L in 64% children, 41~80 IU/L in 17%, 81~200 IU/L in 10%, and beyond 201 IU/L in 9%. The percentage of abnormality of ALT levels in HBeAg positive patients was significantly higher than that of HBeAg negative(P=0.036). Eleven of the 73 HBeAg positive children lost their HBeAg and seroconverted to anti-HBe. In these cases, all had transient elevations in ALT levels before HBeAg seroconversions. The annual rates of spontaneous seroconversion of HBeAg and HBsAg were 9.7% and 0.6%, respectively. Conclusion : Recognition of the dynamics of these changes in viral markers and biochemical findings is needed in the selection and evaluation of therapeutic regimens, establishment of treatment, and calling for controlled trials with adequate follow-up. The hepatitis B carrier state may be asymptomatic in children however, continued surveillance of carriers is important to determine the individual adverse prognostic factors of chronic HBV infections.

• Pediatric Infection and Vaccine
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• v.18 no.2
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• pp.182-192
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• 2011

Purpose : Atopic findings may be associated with severity of pneumonia in 2009 pandemic influenza A (H1N1) infection, which could suggest a possible association between atopic findings and the severity of viral infections. Thus, we studied association between atopic findings and severity of disease in children with H1N1 influenza infection. Methods : A retrospective study was performed in 74 children admitted in a single tertiary institute and confirmed as H1N1 patients by reverse transcriptase (RT) - polymerase chain reaction (PCR). They were divided into 2 groups according to the severity of pneumonia. We evaluated whether the atopic finding is risk factor between the two groups. Results : Children with severe pneumonia had higher percentages of serum eosinophilia (88% vs 40%, P <0.001), asthma (65% vs 35%, P =0.011), allergic rhinitis (71% vs 40%, P =0.009), and IgE level (P =0.007). We found positive correlations between aeroallergen sensitizations and severity of pneumonia (82% vs 53%, P =0.007). Conclusion : Among patients with H1N1 pneumonia, asthma and atopic findings are risk factors for severity of pneumonia.

• The Journal of the Korean Society for Microbiology
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• v.14 no.1
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• pp.79-87
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• 1979

The immunosuppressive activity of newcastle disease virus(NDV) and some possible role of interferon(C-IF) in viral suppression of immune response were evaluated by SRBC-induced delayed-type hypersensitivity(DTH), rosette formation in spleen cells, number of lymphocytes in peripheral blood, hemagglutinin and hemolysin response to SRBC in ICR mice sensitized with SRBC. When NDV was inoculated before or after sensitization of mouse with SRBC, virus caused a marked inhibition of DTH, and its depressive effect was dependent on the time of virus inoculation in relation to SRBC sensitization or challenge. Rosette formation of spleen cells was significantly reduced by NDV infection. The degree of the depression of rosette formation was more prominent in mice inoculated before sensitization than after sensitization and could be related to the amount of serum interferon induced by the virus. Humoral response to SRBC of virus infected mouse was significantly depressed when NDV was inoculated 24 or 48 hours before sensitization. However, there was no difference in the response when the virus was inoculated 9 hour before and at the same time of sensitization or even after that. Lymphocytes in peripheral blood of mice were markedly diminished in numbers when NDV was inoculated 48 and 24 hour before sensitization with SRBC, but they were slightly augmented when the virus was inoculated 9 hour before and at the same time of sensitization. When UV-inactivated or heat-inactivated NDV was injected to the mouse at the same time of sensitization with SRBC, DTH and rosette formation of spleen cells were slightly depressed. DTH and rosette formation in mice treated with crude-IF were generally depressed as com pared with those of control mice. These studies suggest that the NDV causes a significant depression of cell-mediated immunity, whereas the humoral immune response is not inhibited markedly, and that the depression of immune response by NDV infection may be caused by interferon produced by NDV and direct viral activity.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.1 no.1
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• pp.56-78
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• 1998

Objective: Chronic hepatitis B infection (CHB) occurs in 6% to 10% of population in Korea. In ethinic communities where prevalence of chronic infection is high such as Korea, transmission of hepatitis B infection is either vertical (ie, by perinatal infection) or by close family contact (usually from mothers or siblings) during the first 5 years of life. The development of chronic hepatitis B infection is increasingly more common the earlier a person is exposed to the virus, particularly in fetal and neonatal life. And it progress to cirrhosis and hepatocellular carcinoma, especially in severe liver damage and perinatal infection. Histopathology of CHB is important when evaluating the final outcomes. A numerical scoring system which is a semiquantitatively assessed objective reproducible classification of chronic viral hepatitis, is a valuable tool for statistical analysis when predicting the outcome and evaluating antiviral and other therapies. In this study, a numerical scoring system (Ludwig system) was applied and compared with the conventional histological classification of De Groute. And the comparative analysis of cinical findings, family history, serology, and liver function test by histopathological findings in chronic hepatitis B of children was done. Methods: Ninety nine patients [mean age=9 years (range=17 months to 16 years)] with clinical, biochemical, serological and histological patterns of chronic HBV infection included in this study. Five of these children had hepatocelluar carcinoma. They were 83 male and 16 female children. They all underwent liver biopsies and histologic evaluation was performed by one pathologist. The biopsy specimens were classified, according to the standard criteria of De Groute as follows: normal, chronic lobular hepatitis (CLH), chronic persistent hepatitis (CPH), mild to severe chronic active hepatitis (CAH), or active cirrhosis, inactive cirrhosis, hepatocellular carcinoma (HCC). And the biopsy specimens were also assessed and scored semiquantitatively by the numerical scoring Ludwig system. Serum HBsAg, anti-HBs, HBeAg, anti-HBe, anti-HBc (IgG, IgM), and HDV were measured by radioimunoassays. Results: Male predominated in a proportion of 5.2:1 for all patients. Of 99 patients, 2 cases had normal, 2 cases had CLH, 22 cases had CPH, 40 cases had mild CAH, 19 cases had moderate CAH, 1 case had severe CAH, 7 cases had active cirrhosis, 1 case had inactive cirrhosis, and 5 cases had HCC. The mean age, sex distribution, symptoms, signs, and family history did not differ statistically among the different histologic groups. The numerical scoring system was correlated well with the conventional histological classification. The histological activity evaluated by both the conventional classification and the scoring system was more severe as the levels of serum aminotransferases were higher. In contrast, the levels of serum aminotransferases were not useful for predicting the degree of histologic activity because of its wide range overlapping. When the histological activity was more severe and especially the cirrhosis more progressing, the prothrombin time was more prolonged. The histological severity was inversely related with the duration of seroconversion of HBeAg. Conclusions: The histological activity could not be accurately predicted by clinical and biochemical findings, but by the proper histological classification of the numerical scoring system for the biopsy specimen. The numerical scoring system was correlated well with the conventional histological classification, and it seems to be a valuable tool for the statistical analysis when predicting the outcome and evaluating effects of antiviral and other therapies in chronic hepatitis B in children.

• Pediatric Infection and Vaccine
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• v.15 no.2
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• pp.121-128
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• 2008

Purpose : The seasonality of influenza virus and rotavirus are well recognized in winter and so viral surveillance and laboratory-based diagnostics are important to guide the timing of prophylaxis and other interventions. Yet the seasonality of these two viruses are changing in Korea. We evaluated the prevalence and clinical features of influenza virus and rotavirus. Methods : From September 2001 to August 2005, nasopharyngeal aspirates were cultured from the hospitalized patients with lower respiratory infections and the stools from hospitalized patients with gastroenteritis were tested for rotavirus. We retrospectively analysed the medical records. Results : During the study period, respiratory virus was isolated in 578 (18.5%) out of 3,121 patients. Influenza virus was isolated in 143 cases. The seasonal distribution of influenza infection was from December to June of the next year. The ratio of males to females was 1.3:1 and the median age was 17 months. The most common diagnosis of influenza infection was bronchiolitis. Fever and cough were present in 94.4% and 83.9% of the patients, respectively. During the same period, 3,850 patients were admitted for gastroenteritis and 1,047 (27%) patients were positive for rotavirus. Rotavirus was prevailed from December to June of the next year and it presented in year-round. The ratio of males to females was 1.1:1 and the median age was 16 months. Diarrhea and vomiting were the most common symptoms. Conclusion : The recent peak prevalence of influenza virus and rotavirus in Korea was in winter and the late spring, respectively. So we need to expand surveillance and carefully consider the correct period to vaccinate people.