OBJECTIVES: This study was performed to investigate the mumps transmission control status and inapparent infection rate among middle and high school students in Daegu City during a mumps outbreak. METHODS: Nine schools (two middle schools and seven high schools), which reported a number of mumps cases between 2007 and 2008 were selected for investigation. During March-May 2008, a standard questionnaire was distributed to gather information about case identification, instructed isolation measure, isolation status of mumps cases and related factors, and outdoor activities of non-isolated mumps case. Inapparent infection rate was estimated by serum mumps IgM and IgG antibodies status and self-reported mumps symptoms in three of the nine schools. RESULTS: Among 2,560 respondents, more than half of students answered that they did not receive instructions in mumps transmission control measures during the outbreak. Among the 327 mumps cases identified by the questionnaire, 131 cases (40.1%) were considered as isolated and the isolation rates were significantly different among schools, grades, and gender. Of the non-isolated cases, 88.3% continued attending school. Inapparent mumps infection rates were between 56.3% and 70.2%. CONCLUSIONS: Mumps transmission control was inadequate to control the mumps outbreak. Although high inapparent infection rate would mitigate the transmission control effect of case isolation, this measure is fundamental for infection control. The reasons of this inadequate status need to be explored to develop an effective intervention strategy.
Adolescent ; Child ; Communicable Disease Control/*methods ; Disease Outbreaks/*statistics & numerical data ; Female ; Humans ; Immunoglobulin G/blood ; Immunoglobulin M/blood ; Male ; Mumps/epidemiology/*prevention & control/transmission ; Patient Isolation ; Questionnaires ; Republic of Korea/epidemiology ; Schools/*statistics & numerical data ; Students

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) may cause infections during wound dressing. We aimed to compare the antibacterial activities and wound-healing effects of commercially available silver-coated or silver-impregnated wound dressings on MRSA-infected wounds. METHODS: Full-thickness skin defects were made on the back of rats (N=108) and were infected with MRSA. The rats were divided into the following 6 groups according to the dressing used for the wounds: nanocrystalline silver (Acticoat(R)), silver carboxymethylcellulose (Aquacel(R)-Ag), silver sulfadiazine (Medifoam silver(R)), nanocrystalline silver (PolyMem silver(R)), silver sulfadiazine (Ilvadon(R)), and 10% povidone iodide (Betadine(R)). We analyzed the wound sizes, histological findings, and bacterial colony counts for the groups. We also inoculated the silver materials on Mueller-Hinton agar plates containing MRSA and compared the inhibition zones in the agar plates. RESULTS: The order of the rate of wound-size decrease was Acticoat(R)>Aquacel(R)-Ag>PolyMem silver(R)>Medifoam silver(R)>Ilvadon(R)>Betadine(R). The histological findings revealed that the Acticoat(R) showed more reepithelialization and granulation tissue formation and less inflammatory cell infiltration than the other materials. The order of the time required for wound healing was Acticoat(R)>Aquacel (R)-Ag>PolyMem silver(R)>Ilvadon(R)>Medifoam silver(R)>Betadine(R). The bacterial colony counts reduced in all the groups, except in the Medifoam silver(R) group. The order of the size of the inhibition zone was Acticoat(R)>Aquacel(R)-Ag>Ilvadon(R)>PolyMem silver(R)>Betadine(R)>Medifoam silver(R). CONCLUSIONS: Silver-coated or silver-impregnated wound dressings can be used for treating MRSAinfected wounds. Considering its superior efficacy in comparison to the efficacies of other silver-coated or silver-impregnated wound dressings, Acticoat(R) should be preferentially used for the treatment of MRSA-infected skin wounds.
Animals ; Bandages ; Carboxymethylcellulose Sodium/therapeutic use ; Female ; Metal Nanoparticles/therapeutic use ; *Methicillin-Resistant Staphylococcus aureus ; Povidone-Iodine/therapeutic use ; Rats ; Rats, Sprague-Dawley ; Silver/chemistry/*therapeutic use ; Silver Sulfadiazine/therapeutic use ; Skin/pathology ; Staphylococcal Infections/*drug therapy/pathology ; Wound Healing/*drug effects

PURPOSE: Assessing the immunogenicity of a single dose of hepatitis A virus (HAV) vaccines is important because some people receive only a single dose. However, previous studies have shown variable results and have not examined the effects of demographic characteristics other than gender. This study was performed to examine the immunogenicity of a single dose of HAV vaccine according to the vaccine type and demographic characteristics in young adults. MATERIALS AND METHODS: Seronegative medical school students were randomly allocated to receive either Havrix or Epaxal. RESULTS: After approximately 11 months, the seroconversion rate in 451 participants was 80.7%. In men, the Havrix group showed a significantly higher seroconversion rate (81.9%) than the Epaxal group (69.2%), whereas both vaccine groups showed similarly high immunogenicity in women (Havrix: 90.1%, Epaxal: 92.9%; P for interaction=0.062). According to the results of a multivariate analysis, Epaxal showed significantly lower immunogenicity than Havrix only in men. Age, obesity, drinking, smoking, and follow-up time did not significantly affect seroconversion in either gender. CONCLUSION: The seroconversion rate of single-dose HAV vaccines was low in men, particularly in those who received Epaxal. Our results suggest that gender effects should be considered when comparing the immunogenicity of different HAV vaccines.
Adolescent ; Adult ; Female ; Hepatitis A/*immunology/*prevention & control ; Hepatitis A Vaccines ; Hepatitis A Virus, Human/*immunology/*pathogenicity ; Humans ; Male ; Young Adult

PURPOSE: Despite of the high MMR vaccine coverage, the mumps outbreaks is continued in most developed countries including South Korea. To evaluate the effectiveness of MMR vaccine, we carried out mumps outbreak investigation in one kindergarten. METHODS: In Dec. 2006, a mumps outbreak occurred in a kindergarten. Retrospective study was conducted among 212 respondents (205 children and 7 teachers) in 230 study populations (study participation rate: 92%). To define mumps cases, a questionnaire survey, telephone survey, and mumps antibody test with serum were conducted. MMR vaccination status was verified in 198 children using children's vaccination records, National Immunization Registration System and/or medical records of private clinics or hospitals. RESULTS: Over 90% children had received one dose of MMR vaccination. However, 2nd dose of MMR vaccination rate was 45.1%. Attack rates of mumps were 22.9%(22/96) for one dose MMR vaccinees and 3.3%(3/92) for two doses vaccinees. MMR vaccine effectiveness of two doses over one dose was 86%. Mumps attack rate in one dose MMR vaccinees increased by the duration after MMR vaccination. Among all mumps cases, asymptomatic mumps infection identified by IgM positive or IgG over 10,000mIU/ml was 58% (26/ 45). CONCLUSIONS: MMR one dose coverage rate was high(92.1%), but the second dose vaccination rate was very low (45.1%). Mumps attack rate was increased by the duration after the MMR vaccination, and the maximum effectiveness of one dose MMR vaccination was low (77.1%). Therefore, to prevent mumps outbreaks in the kindergarten, second MMR vaccination should be scheduled in 4 years old age, and the coverage rate should be increased over 90%. Further studies for the effectiveness of MMR two doses after 5 and more years are needed.
Child ; Surveys and Questionnaires ; Developed Countries ; Disease Outbreaks ; Humans ; Immunization ; Immunoglobulin G ; Immunoglobulin M ; Measles-Mumps-Rubella Vaccine ; Medical Records ; Mumps ; Mumps Vaccine ; Republic of Korea ; Retrospective Studies ; Telephone ; Vaccination

OBJECTIVES: Few studies have attempted to explain the association between socioeconomic status (SES) and obesity in Korea. Especially the studies on same race with different SES at same time are good for SES influence estimation. The present study highlights the influence of SES of parents on adolescent obesity. The subjects are the same race, but live in different areas, with different SES, Seoul and Yangpung in Korea, and Yanbian in China. METHODS: The cross-sectional study was conducted in Mar-Jun 1996. We carried out anthropometry, 24 hour-recall diet survey, self-reported questionnaire about sociodemographic characteristics and physical activity. For SES indicators, we used income and education of parents. RESULTS: The relationship between SES of parents, defined as educational status, and obesity in boys in Korea and China is direct, but not significant. The relationship is inverse and non-significant among Korean girls. However, for the Korean girls in severe obesity, the relationship is significant. For the Korean-Chinese girls, there is an inverse relationship between the education level and obesity but a direct relationship between the income level of parents and obesity. For the Korean adolescent, there are a direct association between the SES of parents and the nutrients factors such as energy, protein, and fat intake. The energy expenditure of adolescent has no relationship with SES of parents. CONCLUSION: Among boys, the higher the SES, the greater the risk of obese. Among girls in Korea and Korean-Chinese, on the other hand, the lower the educational status of parents, the greater the risk of obese.
Adolescent* ; Anthropometry ; China ; Continental Population Groups ; Cross-Sectional Studies ; Diet Surveys ; Education ; Educational Status ; Energy Metabolism ; Female ; Hand ; Humans ; Korea ; Motor Activity ; Obesity ; Obesity, Morbid ; Parents* ; Pediatric Obesity* ; Surveys and Questionnaires ; Seoul* ; Social Class*

This study was conducted to evaluate the modes of transmission of aseptic meningitis (AM) and hand-foot-mouth disease (HFMD) using a case-control and a case-crossover design. We recruited 205 childhood AM and 116 HFMD cases and 170 non-enteroviral disease controls from three general hospitals in Gyeongju, Pohang, and Seoul between May and August in both 2002 and 2003. For the case-crossover design, we established the hazard and non-hazard periods as week one and week four before admission, respectively. In the case-control design, drinking water that had not been boiled, not using a water purifier, changes in water quality, and contact with AM patients were significantly associated with the risk of AM (odds ratio [OR]=2.8, 2.9, 4.6, and 10.9, respectively), while drinking water that had not been boiled, having a non-water closet toilet, changes in water quality, and contact with HFMD patients were associated with risk of HFMD (OR=3.3, 2.8, 6.9, and 5.0, respectively). In the case-crossover design, many life-style variables such as contact with AM or HFMD patients, visiting a hospital, changes in water quality, presence of a skin wound, eating out, and going shopping were significantly associated with the risk of AM (OR=18.0, 7.0, 8.0, 2.2, 22.3, and 3.0, respectively) and HFMD (OR=9.0, 37.0, 11.0, 12.0, 37.0, and 5.0, respectively). Our findings suggest that person-to-person contact and contaminated water could be the principal modes of transmission of AM and HFMD.
Adolescent ; Child ; Child, Preschool ; Comorbidity ; Disease Outbreaks/*statistics & numerical data ; Enterovirus Infections/*epidemiology/*transmission ; Female ; Hand, Foot and Mouth Disease/*epidemiology/*transmission ; Humans ; Incidence ; Male ; Meningitis, Aseptic/*epidemiology ; Risk Assessment ; Risk Factors ; *Seasons

BACKGROUND: Hepatitis B virus (HBV) infection leads to hepatic and extrahepatic manifestations including chronic kidney disease (CKD). However, the association between HBV and CKD is not clear. This study investigated the association between chronic HBV infection and CKD in a nationwide multicenter study. METHODS: A total of 265,086 subjects who underwent health-check examinations in 33 hospitals from January 2015 to December 2015 were enrolled. HBV surface antigen (HBsAg) positive cases (n = 10,048), and age- and gender-matched HBsAg negative controls (n = 40,192) were identified. CKD was defined as a glomerular filtration rate (GFR) < 60 mL/min/1.73 m² or proteinuria as at least grade 2+ of urine protein. RESULTS: HBsAg positive cases showed a significantly higher prevalence of GFR < 60 mL/min/1.73 m² (3.3%), and proteinuria (18.9%) than that of the controls (2.6%, P < 0.001, and 14.1%, P < 0.001, respectively). In the multivariate analysis, HBsAg positivity was an independent factor associated with GFR < 60 mL/min/1.73 m² along with age, blood levels of albumin, bilirubin, anemia, and hemoglobin A1c (HbA1c). Likewise, HBsAg positivity was an independent factor for proteinuria along with age, male, blood levels of bilirubin, protein, albumin, and HbA1c. A subgroup analysis showed that HBsAg positive men but not women had a significantly increased risk for GFR < 60 mL/min/1.73 m². CONCLUSION: Chronic HBV infection was significantly associated with a GFR < 60 mL/min/1.73 m² and proteinuria (≥ 2+). Therefore, clinical concern about CKD in chronic HBV infected patients, especially in male, is warranted.
Anemia ; Antigens, Surface ; Bilirubin ; Case-Control Studies* ; Female ; Glomerular Filtration Rate ; Hepatitis B Surface Antigens ; Hepatitis B virus ; Hepatitis B, Chronic* ; Hepatitis, Chronic* ; Humans ; Male ; Multivariate Analysis ; Prevalence ; Proteinuria ; Renal Insufficiency, Chronic*

Background Global warming may increase the frequency of compound hot extreme (CHE).However, there is still a lack of studies assessing the associations between CHE and preterm birth (PTB), and the underlying biological mechanisms remain unclear. Objective To estimate the association of exposure to CHE during pregnancy with PTB, and to explore the roles of inflammatory, endothelial dysfunction, and oxidative stress in the association between CHE and PTB. Methods All participants were selected from the Prenatal Environments and Offspring Health (PEOH), a prospective birth cohort conducted in Guangzhou. In this study, a total of 2449 participants who gave birth from May to October in 2014 to 2017 were enrolled, and among them blood samples were collected from 311 preterm (n=43) and full-term (n=268) pregnant women at the time of delivery. A hot day/night was identified as a day when the daily maximum temperature/minimum temperature was higher than its 90th percentile in the study period, and a CHE was defined as having both a hot night and a following hot day. The meteorological data were obtained from the China Meteorological Data Sharing Service System. Anusplin was used to assess the daily maximum temperature, daily minimum temperature, and relative humidity of the participant residence. Enzyme-linked immunosorbent assay (ELISA) was used to measure C reactive protein (CRP), endothelin-1 (ET-1), and malondialdehyde (MDA) levels in maternal serum, and their results were transformed by natural logarithm. A distributed lag nonlinear model was used to investigate the associations of exposures to hot day, hot night, and CHE during pregnancy with PTB at different lag days, and a logistic regression model was used to investigate the associations of CRP, ET-1, and MDA with PTB. Results The incidence rate of PTB was 6.2% in all selected participants. Compared with the non-hot day, the RRs (95%CIs) of CHE in lag 3, 7, and 14 days on PTB were 1.43 (1.12-1.84), 1.24 (1.08-1.43), and 1.17 (1.05-1.30), respectively, and the cumulative effects (% difference) (95%CI) of CHE in lag 14 days on maternal serum CRP, ET-1, and MDA were 0.33% (−0.45%-1.12%), 0.59% (0.11%-1.07%), and 0.57% (0.09%-1.05%), respectively. Compared with the Q1 (lowest quartile) for CRP, ET-1 and MDA, the RRs (95%CIs) of Q4 (highest quartile) for PTB were 1.27 (0.50-3.22), 1.51 (0.61-3.72), and 2.07(0.81-5.27), respectively. Conclusion Maternal exposure to CHE during pregnancy might be associated with an increased risk of PTB. Prenatal exposure to CHE is positively associated with maternal serum CRP, ET-1, and MDA, and the three biochemical indicators are also positively associated with PTB. However, the above conclusions still need further confirmation.