• The Plant Pathology Journal
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• v.39 no.5
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• pp.504-512
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• 2023

After transitioning from periodic to model-based control policy for fire blight blossom infection, it is crucial to provide the timing of field application with easy and accurate information. To assess the risk of blossom infection, Maryblyt was employed in 31 sites across apple-producing regions nationwide, including areas prone to fire blight outbreaks, from 2021 to 2023. In 2021 and 2023, two and seven sites experienced Blossom Infection Risk-Infection warning occurrences among 31 sites, respectively. However, in 2022, most of the sites observed Blossom Infection Risk-Infection from April 25 to 28, highlighting the need for blossom infection control. For the comparison between the two model-based control approaches, we established treatment 1, which involved control measures according to the Blossom Infection Risk-Infection warning and treatment 2, aimed at maintaining the Epiphytic Infection Potential below 100. The analysis of control values between these treatments revealed that treatment 2 was more effective in reducing Blossom Infection Risk-Infection and the number of days with Epiphytic Infection Potential above 100, with respective averages of 95.6% and 93.0% over the three years. Since 2022, the implementation of the K-Maryblyt system and the deployment of Automated Weather Stations capable of measuring orchard weather conditions, with an average of 10 stations per major apple fire blight county nationwide, have taken place. These advancements will enable the provision of more accurate and timely information for farmers based on fire blight models in the future.

• Tuberculosis and Respiratory Diseases
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• v.72 no.2
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• pp.140-148
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• 2012

Background: Detection and treatment of tuberculosis (TB) infection with contact investigation is a key component of TB control program. I evaluated the prevalence and risk factors for TB infection among contacts of recently diagnosed pulmonary TB patients in a tertiary hospital in Korea. Methods: 206 contacts of 90 adult pulmonary TB patients underwent tuberculin skin tests (TST) and chest radiography. The TST results were considered positive with an induration of 10 mm or more, suggesting TB infection. A standardized questionnaire was used to assess risk factors associated with TB infection. Results: TST was positive in 97 of 206 contacts of TB patients (47.1%) and positive rate of TST increased with age. The risk of TB infection was significantly associated with close contact with TB patients (sleeping in the same room) (odd ratio [OR], 4.94; 95% confidence interval [CI], 1.43~17.00). Conclusion: TB infection rate was higher in the elderly, and the risk of TB infection was significantly increased with close contact of TB patients.

• Journal of Korean Biological Nursing Science
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• v.21 no.4
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• pp.300-307
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• 2019

Purpose: The purpose of this study was to provide basic data on the infection prevention management program, which is one of the infectious disease control program by identifying the prevalence and risk factors of latent tuberculosis infection (LTBI) in healthcare workers. Methods: We surveyed a total of 3,046 LTBI test results, including those of 2,269 existing staff and 777 new employees. An interferon-gamma release assay (IGRA) for the diagnosis of LTBI was performed using QuantiFERON^®-TB Gold In-Tube (QFT-IT). The risk factors of LTBI were analyzed using logistic regression analysis. Results: The overall prevalence of LTBI was 16.0% (487/3,046). The prevalence of LTBI in the existing staff was 17.9% (406/2,269) and the prevalence of LTBI in new employees was 10.4% (81/777). Multivariate logistic regression analysis revealed that the risk factors of latent tuberculosis infection among the existing staff were gender, age and work period wheres, the risk factor amongst the new employees depended on their age. Conclusion: The LTBI was not related to the type of occupation and work unit. Therefore, while establishing an infection control program for the prevention of tuberculosis infection at medical institurions, institutional heads and infection control experts should encompass a policy for all the employees.

• Korean Journal of Health Education and Promotion
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• v.27 no.1
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• pp.1-8
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• 2010

Objectives: Human papillomavirus (HPV) infection is highly associated with cervical cancer. So, the modification of the risk factors of HPV infection is essential for prevention of cervical cancer. This study was performed to evaluate the risk factors of HPV infection. Methods: HPV test of 12,337 study population conducted using Hybrid-Capture II assay(HC-II) and self-administered questionnaires were collected. The study population was people who visited hospital-based medical screening center from January to December 2007 and all were female employees or employees' partner. Results: In logistic regression analysis, smoking and alcohol drinking were significant factors, with odds ratios of 1.328 (95% CI 1.010~1.746) and 1.644 (95% CI 1.309~2.066), respectively. Nutritional supplements was also significant factor, which odds ratio was 1.161 (95% CI 1.004~1.343). Oral contraceptives was positive association with HPV infection (odds ratio 2.108; 95% CI 1.217~3.652), whereas condom was negative association (odds ratio 0.851; 95% CI 0.740~0.979). Conclusion: HPV Prevalence of 12,377 study population was 11.4%. Smoking, alcohol drinking, nutritional supplements and oral contraceptives were possible risk factors of HPV infection, and condom had possible preventive effect on HPV infection. Further prospective and comprehensive studies about HPV risk factors are required.

• The Plant Pathology Journal
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• v.28 no.2
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• pp.172-184
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• 2012

An infection risk model for Phytophthora blight on chili pepper was developed to estimate the first date of disease occurrence in the field. The model consisted of three parts including estimation of zoosporangium formation, soil water content, and amount of active inoculum in soil. Daily weather data on air temperature, relative humidity and rainfall, and the soil texture data of local areas were used to estimate infection risk level that was quantified as the accumulated amount of active inoculum during the prior three days. Based on the analysis on 190 sets of weather and disease data, it was found that the threshold infection risk of 224 could be an appropriate criterion for determining the primary infection date. The 95% confidence interval for the difference between the estimated date of primary infection and the observed date of first disease occurrence was $8{\pm}3$ days. In the model validation tests, the observed dates of first disease occurrence were within the 95% confidence intervals of the estimated dates in the five out of six cases. The sensitivity analyses suggested that the model was more responsive to temperature and soil texture than relative humidity, rainfall, and transplanting date. The infection risk model could be implemented in practice to control Phytophthora blight in chili pepper fields.

• Korea Journal of Hospital Management
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• v.24 no.3
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• pp.11-26
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• 2019

Objectives: The purpose of this study was to investigate the effect of the perception on the quality of nosocomial infection control on perceived risk, trust, and the intention to revisit among the medical consumers. Method: 361 patients and their guardians who were hospitalized in women's hospital, Gangnam-gu, Seoul, participated in this study. The data was analyzed using SPSS Statistics 21.0. Results: The perception on the quality of nosocomial infection control had a negative(-) effect on perceived risk, a positive(+) effect on trust, a positive(+) effect on the intention to revisit. The perceived risk had a negative(-) effect on trust, a negative(-) effect on the intention to revisit. The trust had a positive(+) effect on the intention to revisit. The perceived risk was partially mediated by the perception on the quality of nosocomial infection control and the intention to revisit, while the trust was fully mediated by the perception on the quality of nosocomial infection control and the intention to revisit. Thus, it indicated that the perceived risk and trust had dual mediated effects as well as full mediated effects in the relationship between the perception on the quality of nosocomial infection control and the intention to revisit. Conclusions: The nosocomial infection control can be an important factor to contribute to hospital management by attract the loyal medical customers, not just cost-expenditure. The nosocomial infection control can help hospital revenue and customer management strategy. Thus, it will contribute to the effective marketing strategy in the medical field.

• Particle and aerosol research
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• v.16 no.4
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• pp.73-94
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• 2020

Particulate infectious sources, including infectious viruses, can float in the air, causing airborne infections. To prevent indoor airborne infection, dilution control by ventilation and indoor air cleaners are frequently used. In this study, the risk of airborne infection by the operation of these two techniques was evaluated. In case of dilution control by ventilation, a high efficiency air filter was embedded at the inlet of supply air. In this study, infectious source reduction devices such as indoor air cleaner include all kinds of mechanical-filters, UV-photo catalysts and air ionizers through which air flow is forced by fans. Two mathematical models for influenza virus were applied in an infant care room where infants and young children are active, and the risk reduction efficiency was compared. As a result, in the case of individually operating the ventilator or the infectious source reduction device, the airborne infection risk reduction efficiencies were 55.2~61.2% and 53.8~59.9%, respectively. When both facilities were operated, it was found that the risk of airborne infection was reduced about 72.2~76.8%. Therefore, simultaneous operation of ventilation equipment and infectious source reduction device is the most effective method for safe environment that minimizes the risk of airborne infection of respiratory infectious diseases. In the case of a space where sufficient ventilation operation is difficult, it was found that the operation of an infectious source reduction device is important to prevent the spread of infectious diseases. This study is meaningful in that it provides an academic basis for strategies for preventing airborne infection of respiratory infectious diseases.

• Korean Journal of Occupational Health Nursing
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• v.11 no.1
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• pp.44-51
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• 2002

Purpose: Surgical Site Infection(SSI) is the third most common cause of nosocomial infection, so that it results in serious socioeconomic impact such as extra hospitalization, mortality and health care cost. The aim of this study was to analyses the SSI that based on the degree of wound contamination and patient risk index after general surgery and to generate a reference data for the effective management and reducing SSI. Method: From July, 1999 to June, 2000, 1080 cases which presented with surgical site infection after general surgery at S hospital in chunchon city were included in this study. The data were collected by review of the medical records retrospectively. The collected data, in accordance with the test purpose, is analyzed by SPSS/PC+ program, using real numbers, percentage, $X^2$ test, Pearson's correlation and stepwise logistic regression. Result: The overall wound infection rate was 4.7%(51 cases out of 1,080). The infection rate of clean wounds was 1.4%. Surgical site infection rate for patient risk index scores of 0, 1, 2 and 3 was 1.9%, 8.0%, 13.1% and 20.0%, respectively and increased significantly according to patient risk index(p=.000). Sixteen of the fifty one(31.4%) surgical site infections were found during an outpatient visit after discharge. Multivariate analysis, identified two independent variables : duration of postoperation stay(p=.000), age(p=.037). The most frequent isolated organisms were Pseudomonas aeruginosa(21%) and Staphylococcus aureus(21%). Also Staphylococcus aureus were all MRSA(Methicillin Resistant S. aureus). Conclusion: In this study, SSI was analysed according to the degree of wound contamination and patient risk index after general surgery. The data that obtained from this study is expected that it would be available for surveillance and control of SSI.

• Parasites, Hosts and Diseases
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• v.55 no.2
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• pp.203-206
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• 2017

The seroprevalence of human toxoplasmosis has been increasing in Korea, and it is controversial whether cats are an important infection source or not. This study was performed to evaluate the seroprevalence of Toxoplasma gondii infection in a high risk group (cat sitters) and to determine the possible importance of cats as an infection source in Korea. Risk factors, including the age, sex, and diet of cat sitters, their contact experience and contact frequency with stray cats, and origin, number, and outdoor activity of their pet cats, were analyzed using structured questionnaires. A total of 673 serum samples from people who have frequent contact with cats (high risk group) and 1,114 samples from general people (low risk group) were examined for specific IgG antibodies against T. gondii by ELISA. The results revealed that the overall seroprevalence of T. gondii infection was 7.4% (n=1,787). The seroprevalence among low risk group was 8.0% (89/1,114), whereas that among high risk group was rather lower 6.4% (43/673), though this difference was statistically not significant (P=0.211). Among the risk factors, only the outdoor activity of pet cats was important; people having cats with outdoor activities revealed 2 times higher seroprevalence than people having cats with only indoor activities (P=0.027). In conclusion, the seroprevalence of T. gondii was not significantly different between the high risk group and low risk group, and the importance of cats as a source of infection in Korea is questionable.

• Journal of Veterinary Clinics
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• v.32 no.1
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• pp.78-84
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• 2015

Although researches have highlighted the important role of enhanced farm biosecurity to reduce the severity and prevalence of diseases in livestock, to date there has been little study in Korea on farmers' adoption of biosecurity measures to control porcine reproductive and respiratory syndrome virus (PRRSV) infection. To mitigate the risk of PRRSV infection in pigs, the risk factors by which PRRSV is introduced in pig farms must be determined. The primary aim of this study was to investigate pig producers' perceptions about on-farm biosecurity practices. We also analyzed data obtained from a cross-sectional study on 196 farrow-to-finish farms conducted between March 2013 and February 2014 to identify risk factors for PRRSV infection at farm level. Standardized questionnaires with information about basic demographical data and management practices were collected in each farm by on-site visit of trained veterinarians. Farms were classified as negative or positive through the use of infection profiles that combined data on PCR positive pigs and serological testing including antibody titer, sero-conversion pattern at each age category, and vaccination status. Data on biosecurity practices, farm management and environmental characteristics were analyzed using multivariate ordinal logistic regression. Generally, the biosecurity level in the pig farms included in this study were insufficient to reduce/prevent the risk of PRRSV infection given the high pig density areas and the considerable extent of vehicle movement. Factors associated with PRRSV infection were those where owners used on-farm vaccination programs had a lower risk of infection (OR = 0.19, 95% CI 0.06-0.61). The results from the analysis may guide to tailor biosecurity measures in the reduction or prevention of PRRS to the specific circumstances of pig farms in different localities of the world. To the best knowledge of the authors, this is the first study to report information on the biosecurity practices currently implemented on Korean pig farms.