• Korean Journal of Microbiology
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• v.44 no.3
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• pp.221-227
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• 2008

Bordetella pertussis is pathogenic bacteria causing pertussis, a infectious respiratory disease for the infants. The incidence rate of pertussis was significantly decreased after introduction of vaccine. However, increased pertussis cases are recently reported in several countries with high vaccine coverage. One of the inferred reasons is genotype or serotype variation between circulating strains and vaccine strains. Therefore, it is required to confirm the variation status of the isolates by genotype or serotype analysis and the possibility of pertussis outbreak in Korea should be estimated. For this, the serotype variations of the isolates from $1999\sim2006$ were investigated in agglutinogen and fimbriae. As the result, the most frequent serotype in the isolated strains was agglutinogen 1 and fimbriae 2 serotypes. Moreover, serotype transition from vaccine serotypes to non-vaccine serotypes was observed. Especially, the transition pattern of agglutinogen serotype was directed to increase a different type (agg 1) from the vaccine type (agg 1,2). However, in case of fimbriae, the same type (fim 2) with vaccine strain was increased. These results were also observed in other countries with increasing incidence of pertussis. For more predictable results to know increasing possibility of pertussis incidence in Korea, the studies on genetic variations of antigenic determinant genes and prevalence of antibody titer in normal population should be performed in the further.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.219-222
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• 2010

In this study, we evaluated Vi-passive hemagglutination (Vi-PHA), SD Salmonella Typhi IgG/IgM ($SD^{(R)}$ kit) and Widal test for the rapid laboratory diagnosis of typhoid fever patients. A total of 36 serum samples from febrile patients in Korea from 2005 to 2006 were used. Among 36 patients, 27 were fever patients without typhoid, 9 were typhoid fever. Vi-PHA showed 8 positive results out of 9 typhoid fever patients (sensitivity 88.9%) and 1 positive and 26 negative results out of 27 febrile patients without typhoid (specificity 96.3%). The sensitivity and the specificity of $SD^{(R)}$ kit were 100% and 92.6%, respectively. However, the sensitivity and the specificity of Widal O & H tests were 88.9%, 100%, and 77.8%, 70.4%, respectively. Consequently, Widal H and $SD^{(R)}$ kit showed higher sensitivity and Vi-PHA showed higher specificity. To efficient diagnosis, Vi-PHA may be sufficient diagnosis method in acute cases and $SD^{(R)}$ kit and Widal test may be sufficient in sporadic area and high risk group.

• Journal of Preventive Medicine and Public Health
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• v.55 no.3
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• pp.263-272
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• 2022

Objectives: Infections with hepatitis B, C, and D virus (HBV, HCV, and HDV) are a major public health problem and lead to serious complications such as cirrhosis and hepatocellular carcinoma. We aimed to determine the seroprevalence of hepatitis B surface antigen (HBsAg), anti-HCV, anti-HDV immunoglobulin G, alpha-fetoprotein (AFP), and dual and triple hepatitis virus infections in Mongolia. Methods: A total of 2313 participants from urban and rural regions were randomly recruited for this cross-sectional study. A questionnaire was used to identify the risk factors for hepatitis virus infections, and the seromarkers were measured using immunoassay kits. Results: Among all participants, the prevalence of HBV, HCV, and HDV was 15.6%, 36.6%, and 14.3%, respectively. The infection rates were significantly higher in females and participants with a lower education level, rural residence, older age, and a history of blood transfusion. HBV and HCV co-infection was found in 120 (5.2%) participants and HBV, HCV, and HDV triple infection was detected in 67 (2.9%) participants. The prevalence of elevated AFP was 2.7%, 5.5%, and 2.6% higher in participants who were seropositive for HBsAg (p=0.01), anti-HCV (p<0.001), and anti-HDV (p=0.022), respectively. Elevated AFP was more prevalent in participants co-infected with HBV and HCV (5.8%, p=0.023), HBV and HDV (6.0%, p<0.001), and triple-infected with HBV, HCV, and HDV (7.5%) than in uninfected individuals. Conclusions: Nearly half (49.8%) of the study population aged ≥40 years were infected with HBV, HCV, or HDV, and 22.4% had dual or triple infections.

• Pediatric Infection and Vaccine
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• v.6 no.2
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• pp.210-218
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• 1999

Purpose : As several epidemics of aseptic meningitis had been reported in Korea since 1990, the need of epidemiologic study about enteroviral infections was recognized. We studied epidemiologic and clinical features of enteroviral infections in children. Methods : We analyzed the seasonal occurrence of enteroviral infections and age, sex and clinical diagnosis of the children admitted to five branch hospitals of Hallym University and diagnosed to have enteroviral infections by culture from January 1996 to December 1998. Results : Enterovirus was isolated in 126 out of 245(51.4%) stools, 15 out of 89(16.8%) nasopharyngeal aspirates and 195 out of 1,835(10.6%) cerebrospinal fluids. There were 273 echoviruses(Echo)(197 Echo 30, 46 Echo 9, 17 Echo 6, 13 unclassified), 24 coxsackieviruses B(CB)(11 CB 2, 2 CB 5, 11 unclassified), 7 coxsackieviruses A 24 and 32 unclassified enteroviruses. Yearly number of isolates was 65(46 Echo 9) in 1996, 239(197 Echo 30) in 1997 and 32(15 CB: 9 CB 2) in 1998. Epidemics of enteroviruses occurred mainly during the months May to October. The mean age of the infected children was $62.1{\pm}38.0$ months and 74.6% of the patients were younger than 7 years of age. There were 203 boys and 100 girls and 79.3% of the patients were diagnosed as aseptic meningitis. Conclusions : We confirmed that enteroviral infections occurred in epidemics from late spring to fall during the study period. Enteroviral infections occurred predominantly in boys and the preschool children. Aseptic meningitis was the main illness in the hospitalized children.

• Clinical and Experimental Pediatrics
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• v.48 no.1
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• pp.40-47
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• 2005

Purpose : S. pneumoniae is one of major pathogens of community-acquired respiratory infections. The rate of antibiotic resistance to this organism has increased, and resistance to multiple antimicrobial agents in a single strain of S. pneumoniae may compromise the efficacy of empiric antimicrobial treatment commonly used for respiratory infections. We did this study to find out the penicillin resistant distributions and oral antibiotics susceptibility patterns against S. pneumoniae, isolated from pediatric patients with community-acquired respiratory infections in Korea. Methods : One hundred fifty six pneumococcal isolates obtained from pediatric patients with community-acquired respiratory infections such as acute otitis media(AOM), sinusitis and pneumonia between May 2000 to June 2003. And MICs of penicillin and oral antibiotics(amoxicillin, amoxicillin-clavulanate, cefaclor) were performed by broth microdilution methods according to the NCCLS(2003a). Results : Seventy eight percent of the isolates were resistant to penicillin. The isolates, collected from AOM patients showed the highest penicillin resistance(92.7%). The resistant rates of amoxicillin (16.7%) and amoxicillin-clavulanate(9.6%), based on susceptibility breakpoints established by the NCCLS, were markedly lower than these of penicillin. But, the resistant rate of cefaclor was very high, above 95%. Conclusion : We concluded that pneumococci isolated from study cases may be one of the world's highest penicillin resistant rates. But, amoxicillin and amoxicillin-clavulanate can be used as a first-line antibiotics. Finally, we hope that a continuous surveillance study to monitor resistant patterns of pneumococcal respiratory infections will be needed for the standard guidelines of empiric antibiotic treatment.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.13 no.2
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• pp.134-145
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• 2010

Purpose: The serologic diagnosis of rotaviral infections is not commonly used in clinical practice, but is used in seroepidemiologic studies. In this study, the usefulness of Escherichia coli-expressed recombinant VP6 proteins of group A rotavirus in the serodiagnosis of rotavirus infections by ELISA was evaluated. Methods: The recombinant VP6 proteins of group A rotavirus expressed in E. coli Rosetta II strain were purified and identified. One hundred sera from 22 children (4 healthy neonates, 13 healthy children, and 5 immunocompromised children) who had serial sera samples prior to and after rotavirus infections were provided by the Gyeongsang National University Hospital, a member of the National Biobank of Korea. IgG, IgA, and IgM antibodies against rVP6 were analyzed by ELISA in all of the patients and Western blot analysis in 4 neonates. Results: ELISA tests using rVP6 proteins of group A rotavirus as antigen revealed that IgG, IgA, and IgM antibodies increased after rotaviral infections in most neonates and healthy children. IgG antibodies also increased after rotaviral infections in most immunocompromised children without an adequate increase in IgM or IgA antibodies. Western blot analysis in four neonates revealed very early IgM antibody responses, even in the sera with low optical densities in ELISA tests. Conclusion: Our study showed that ELISA using rVP6 as an antigen is a valid diagnostic tool for seroepidemiologic studies of rotavirus infections and Western blot analysis is a sensitive test in detecting IgG, IgA, and and IgM antibodies in patients with rotavirus infections.

• Journal of the korean veterinary medical association
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• v.15 no.7
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• pp.369-379
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• 1979

• The Journal of the Korean Society for Microbiology
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• v.35 no.5_6
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• pp.340-342
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• 2000

• Clinical and Experimental Pediatrics
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• v.62 no.10
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• pp.382-383
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• 2019

• The Journal of the Korean dental association
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• v.19 no.10 s.149
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• pp.835-837
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• 1981