• Pediatric Infection and Vaccine
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• v.9 no.1
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• pp.61-66
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• 2002

Purpose : To determine wether varicella can be prevented by administration of oral acyclovir(ACV) during the incubation period of the disease. Methods : Starting 9 days after exposure to the index case in their families, ACV(40 mg/kg/day in four divided doses) was given orally to 20 exposed children for 5 days. Their clinical features was compared with those of 20 control subjects. Antibody titers to VZV were measured in both group 1 week and 4 weeks after finishing the oral ACV administration. Results : The mean age of family members with varicella(51.4 months) were significantly high compared to that of ACV prophylaxis group(28.5 months) and control group(31 months) (P<0.05). Among the 12 children with ACV prophylaxis who completed follow up blood sampling, nine children were diagnosed as VZV infection on the serologic test(75%). Among them six children showed positive VZV IgM on the first blood sample and two children showed serocoversion to positive IgM on the second test after ACV prophylaxis. One child who was negative on both IgM and IgG, showed positive IgG on the second test. The incidence of fever and severity of skin rashes were significantly low in children received oral ACV than in the control group. No or reduced number of maculopapular eruption were observed in the oral ACV group compared to multiple vesicles of the control group. Conclusion : In the present study, we observed that oral ACV prophylaxis to the family contacts is effective in reducing severity of skin lesion. It is likely that oral ACV 9 days after contact prevents or reduces blood dissemination of VZV. Little is known about clinical effect and immunity to the virus in exposed children with no varicella symptom after treatment. We propose the checking up antibody to VZV some period after oral ACV, and considering vaccination to whom with no antibody. But further more studies are needed to practical application of oral ACV for the postexposure prophylaxis of varicella.

• Pediatric Infection and Vaccine
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• v.9 no.1
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• pp.79-84
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• 2002

Purpose : About 41% of obtained group A streptococci in the 1998 was reported as erythromycin-resistant streptococci in Seoul, Korea. The most common T serotype was T12, followed by T4 and T28. We'd like to monitor the serological changes and antibiotic sensitivity test of Streptococcus pyogenes obtained from the patients with pharyngotonsillitis and invasive diseases from 1999 through 2001. Also, it could be proposed to choose the proper antibiotic selection in the area where the rate of erythromycin-resistant streptococci is high. Methods : From Jan. 1999 to Oct. 2001, 208 isolates of group A streptococci were collected from inpatients and outpatients with pharyngotonsillitis, scarlet fever, and invasive infections in Seoul and Southern part of peninsula. All isolates were serotyped by T-agglutination, minimum inhibitory concentrations(MICs) which were determined by agar dilution methods, according to the guidelines of the National Committee for Clinical Laboratory Standards (NCCLS). Results : The most common T serotype was T12(29.8%), followed by T1(23.1%), T4 (14.9%). T1 was prominent serotype compared with previous year. T serotyping, among 25 isolates obtained from the patients with scarlet fever in Southern part of peninsula mostly, was T12, T1, and T4 in order of frequency. All the isolates tested were susceptible to penicillin, cefprozil, vancomycin, ceftriaxone, and chloramphenicol. However, 23 isolates(14.2%) was resistant to erythromycin and 18 isolates(11.1%) was resistant to clarithromycin. Serotype T12 was found to be the most resistant serotype to erythromycin and/or clarithromycin. Conclusion : High rate of erythromycin-resistant streptococci which surveyed in 1998 were reduced to 14.2% in this study. We should have to further evaluate the reason of decreased resistant strains and consider the resistant strains of streptococci in choosing the antibiotics. There was no serological characteristics according to the types of disease entities. Between the serologic distributions in Seoul and the Southern part of peninsula area are same, we could presume that the serological typing of strains obtained over the country may be not different.

• Pediatric Infection and Vaccine
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• v.4 no.2
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• pp.225-231
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• 1997

Purpose: To evaluate the postnatal changes of serum levels of mumps- and rubella-specific IgG antibody in unvaccinated infants, this study was performed using enzyme linked immunosorbent assay(ELISA). The sera were collected from 103 unvaccinated infants under 15 months of age. The results obtained were as follows. 1) The seropositivities and the levels of mumps specific IgG decreased by ages, 70.6% in month, 50.0% in 2~3 months, 6.7% in 4~5 months and 0% after 6 months of age respectively. 2) The seropositivities of rubella-specific IgG were 58.8 % in 1 month, 70% in 2~3 months, 13.3% in 4~5 months, and 0% after 6 months of ages in unvaccinated infants respectively. 3) The seropositivities and antibody levels of mumps and rubella specific IgG had significantly decreased with age, and there was negative correlation between ages of infants and mumps or rubella-specific IgG levels(correlation coefficient r=-0.500, P < 0.001). Conclusions: The seropositivities of transplacental antibodies of mumps and rubella in unvaccinated infants were 0% after 6 months of age. These transplacental antibodies disappeared earlier age than we had thought.

• Pediatric Infection and Vaccine
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• v.4 no.2
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• pp.210-217
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• 1997

Purpose: To prevent residual physical disability and chronic infection, prompt diagnosis and adequate treatment are important in the skeletal infections in children. Although radioisotope scanning is knwon as the method of choice for early diagnosis of bone infection, we conducted a study on twenty nine children who had skeletal infections to reevaluate the most appropriate way in diagnosis and management. Methods: A retrospective study was conducted on twenty nine children, who were admitted to the departments of Pediatrics and Orthopedic Surgery and who had acute osteomyelitis or septic arthritis, through review of medical records, radiologic & radioisotope study results. Their diagnoses were confirmed by bacteriologic cultures on the aspirated specimens from suspected bony lesions. Results: 1) Among twenty nine patients, there were 6 infants including 5 newborn infants, and 23 children were aged between 1 and 15 years. Male to female ratio was 1.4 to 1. 2) Point tenderness was noted in all cases, and the common physical signs were swelling, limitation of motion, fever and local heat in the order of frequency. 3) Fifty two percents of the patients were diagnosed within a week after onset of symptoms and all cases were within 15 days. 4) Leukocytosis was noted in only 58.6% of cases but erythrocyte sedimentation rate was increased in all cases except only one case. Staphylococcus aureus was revealed as the most common etiologic agent. 5) Radioisotope scans showed hot uptake in five of six cases(83.3%) who had no abnormal finding on plain skeletal radiolograms. Conclusions: Although radioisotope scan and MRI are helpful in early diagnosis before radiologic finding was detected on plain X-ray film, the antimicrobial therapy can be started after bacteriologic study of the aspirated specimens from the suspected skeletal lesions if skeletal infection is highly suspected clinically.

• Pediatric Infection and Vaccine
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• v.4 no.2
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• pp.265-270
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• 1997

Purpose: Rapid diagnosis and prompt treatment remain the cornerstone of management of patients with meningitis. Examination of cerebrospinal fluid(CSF) for glucose, protein, cells, and organisms is necessary for accurate diagnosis, but in many parts of the world facilities do not exist to do so. We tested CSF samples from 69 children with suspected meningitis with urinary reagent strips and analyzed the results to know the usability of urinary reagent strips in diagnosis of meningitis. Methods: 69 CSF samples obtained from children with suspected meningitis were analysed. Each sample was divided into two; one was sent to the laboratory for routine diagnostic evaluation, and the other was tested with the reagent strip(Combur10 Test M). Laboratory values of CSF glucose, protein, and leucocytes for each CSF sample were plotted against the corresponding reagent-strip category. Results: There was good agreement between the dipstick and laboratory values for CSF protein and cell count but not for glucose. Conclusion: Rapid diagnosis of meningitis could be made with three component of the Combur10 test strip. It is easy to do and would be of particular value to those working in parts of the world where no laboratory facilities exist.

• Pediatric Infection and Vaccine
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• v.4 no.2
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• pp.240-256
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• 1997

Purpose: To evaluate the hepatitis B vaccination program which has been conducted since 1980, Korea. Methods: This study was carry out self reported questionnaire and serologic test covering 2,072 elementary school students who were born between 1980 and 1987, selected by cluster sampling. The HBV serologic markers (HBsAg, Anti-HBs and Anti-HBc) were tested by radioimmunoassay (RIA). The contents of questionnaire include demographic data of students and parents, vaccination status, vaccination frequency, vaccination age, past history of mother's HBV test. Results: 1) The HBsAg positive rates by sex showed 3.7% for male and 2.7% for female, representing an average rate of 3.4%. The HBsAg positive rates by age group showed 5.6% for 13 years and l.5% for 6 years, representing a tendency of lowering rate as ages being younger. 2) The pre-natal HBV test rate was 10.2%, while post-natal HBV test rate was 42.5%. The test showed that the parents' educational level being higher than others, the pre- and post-natal HBV test showed higher rates. In case the fathers occupation being office worker, the post-natal HBV test showed a higher rate compared with other occupation. 3) Overall vaccination rate was 82.6%, complete vaccination rate 69.8%, booster injection rate 42.8%. The vaccination rate, complete vaccination rate and booster injection rate increased as the age being younger. If the educational level of parents were higher, the vaccination rate, complete vaccination rate and booster injection rate showed higher rates. Younger students showed younger vaccination age, and higher educational background of family showed younger vaccination ages. 4. With regard to positive rate of HBV markers by vaccination age, HBsAg and Anti-HBc positive rate showed higher degrees in the following order; preschool age (1-6 years), school age (6-13 years) and infancy (0-1 year). Anti-HBs positive rate was increased as the frequency of vaccination increased. Five years after initial complete vaccination, minimum protective rate was lowest, 69.6%.

• Pediatric Infection and Vaccine
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• v.4 no.2
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• pp.232-239
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• 1997

Purpose: The incidence of hepatitis A virus(HAV) infection has markedly decreased in the last 20 years due to industrialization and improvements in the standard of living and hygiene in Korea. The reduction in seroprevalence rates indicates infection potential for young adult population, and a need for vaccinations in high-risk adults and children groups has been suggested. In this study we evaluated the seroprevalence rates and natural infection rates of hepatitis A in children and adolescent to obtain the basic data for vaccination of hepatitis A. Methods: A total of 334 children and adolescent subjects below 20 years old in Kyonggi-do province were examined for HAV antibody and seroprevalence rates in each age group was investigated. In 584 elementary school students residing in Kyonggi-do province, serum samples collected in 1993 and 1996 from the same subjects for investigation of natural seroconversion rates. Method of testing antibody was enzyme immunoassay. Results: 1) The seropositive rate of HAV in 334 subjects aged below 20 years old was 5.4%. According to age, the seropositive rates were 27.3% in infant group, 0.0% in 1~4 year-old group, 0.0% in 5~9 year-old group, 2.9% in 10~14 year-old group and 15.0% in 15~19 year-old group. 2) In the study of 584 elementary school children, only one subject showed seropositive in 1993, and in 1996 three different subjects showed seropositive results(0.5%); the natural seroconversion rate during 3 years was 0.5%. 3) The seroprevalence rates of below 20 year-old subjects reported in previous studies were 63.8% in 1979 and 47.3% in 1989 while the present study showed the rate at 5.4%. Conclusion: Since natural antibody formation is rarely occurring, there is a high risk for apparent hepatitis A infection in adults. Therefore vaccination in high risk groups is essential at present, and in order to reduce the chance for hepatitis A infection in adults, vaccination in children may be needed.

• Pediatric Infection and Vaccine
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• v.18 no.2
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• pp.135-142
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• 2011

Purpose : Hospital associated infection (HAI) caused by multidrug-resistant (MDR) microorganisms has been recognized as an important issue in the world, especially in critically ill patients such as the patients admitted in the intensive care unit. There are fewer papers about MDR-HAI in pediatric patients compared to adult patients. In this study, we investigated the incidence and associated factors of MDR-HAI in children admitted to the intensive care unit (ICU) of a university hospital. Methods : We retrospectively evaluated 135 children who were admitted in ICU for at least 3 days between January 2009 and December 2010. HAI cases were divided into MDR-HAI group and non-MDR-HAI group. Clinical characteristics and various associated factors were compared between those groups. Results : In 39 patients, 45 cases of ICU-related HAI were developed. ICU-related HAI incidence was 47.7 per 1000 patientdays. Thirty-six cases (80.0%) were MDR-HAI. Acinetobacter baumannii was isolated more commonly in MDR-HAI group. And the followings were found more frequently in MDR-HAI group than non-MDR-HAI group: medical condition as an indication for ICU admission, mechanical ventilation, urinary catheterization and previous use of broad-spectrum antibiotics. Among the risk factors, previous use of broad-spectrum antibiotics was the independent risk factor for MDR-HAI. Conclusion : ICU-related HAI incidence was higher than previously reported. Previous use of broad-spectrum antibiotics was the independent risk factor for MDR-HAI. To investigate the characteristics of MDR-HAI in children admitted in ICU, further studies with a larger sample size over a longer period of time are warranted.

• Pediatric Infection and Vaccine
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• v.18 no.2
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• pp.124-134
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• 2011

Purpose : We have tried to search all concerning data on the policies of hepatitis B vaccination or surveillance of medical equipments that can transmit blood mediated diseases, including disposable syringe, in Republic of Korea, to propose references to other medical professionals. Methods : Data from domestic journals, government websites, computerized newspapers, etc. were reviewed. The data were arranged into four categories (governmental policies on hepatitis B control, hepatitis B mass immunization program in school, using process of hepatitis B vaccine, and policies on medical equipments surveillance, including disposable syringes, which is considered as source of blood mediated infection), and the periodic changes on each subjects in policies were reviewed. Results : Due to growing social concerns on hepatitis B in early 1980s, swift introduction and production of hepatitis B vaccine was made. After establishment of "5 year project for eradication of hepatitis B" in late 1983, number of vaccinated population jumped up to 6 million within 2 years (1984-85). However, since the immunization targets were mainly adult, not infant, this project was annulled in late 1985. Following this project, hepatitis B mass immunization program in school was carried out. In year 1995, hepatitis B vaccine was included in national immunization program. The use of disposable syringe was recommended from year 1980 but legislated in year 1985, finally. Conclusion : The mainstay in controlling hepatitis B in Republic of Korea was coordination of prompt introduction of vaccine, mass immunization, high vaccination coverage rate, or use of disposable syringes. However, since there is lack of official data available, it is urgent to arrange and computerize all government data related to infectious diseases.

• Pediatric Infection and Vaccine
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• v.18 no.2
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• pp.109-116
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• 2011

Purpose : Pneumococcus is one of the most important causes of invasive infection through the childhood period. In January 2008, the Clinical and Laboratory Standards Institute (CLSI) published revised penicillin breakpoints for Streptococcus pneumoniae and penicillin susceptibility rates of S. pneumoniae increased in Korea. This study was performed to determine the probability of oral amoxicillin for the empirical treatment achieving bactericidal exposure against pneumococcus using pharmacodynamics model. Methods : Twenty-three isolates of pneumococci were subjected to determine minimum inhibitory concentration (MIC) for ${\beta}$-lactams and macrolide. For the ${\beta}$-lactams, exposure of fT >MIC (time that free drug concentrations remain above the MIC) for 50% of the administration interval have determined the probability of target attainment (PTA), and regimens that had a PTA >90% were considered optimal. An analysis was performed by applying MIC of 23 isolates to a 5000-patient Monte Carlo simulation model. Results : Among 23 isolates from healthy children, 7 (30.4%) isolates were MIC ${\leq}$1.0 ${\mu}g$/mL and 19 (82.6%) were MIC ${\leq}$2 ${\mu}g$/mL for amoxicillin. Amoxicillin 40 mg/kg/day achieved PTA >90% at MIC ${\leq}$1.0 ${\mu}g$/mL but PTA decreased to 52% at MIC 2 ${\mu}g$/mL, whereas amoxicillin 90 mg/kg/day can predict 97% of PTA at MIC 2 ${\mu}g$/mL. Overall, oral amoxicillin 90 mg/ kg/day for the empirical treatment against pneumococcus can expect more successful response in Korean children. Conclusion : Considering the resistantce pattern of pneumococci in Korean children, we estimate that oral amoxicillin 90 mg/kg/day will provide a pharmacodynamic advantage for the empirical treatment against pneumococcus. And low dose amoxicillin or macrolide are expected to have higher chance of treatment failure than high dose oral amoxicillin.