Does having various types of fear related to COVID-19 disrupt individuals’ daily life?: Findings from a nationwide survey in Korea / 한국역학회지

OBJECTIVES@#Unexpected changes in daily routines caused by the coronavirus disease 2019 (COVID-19) pandemic may affect psychological health. This study investigated the association between various types of COVID-19-related fear and the subjective level of disturbance in daily activities experienced by individuals. @*METHODS@#This cross-sectional study used the Korea Community Health Survey conducted from August through November 2020. COVID-19-related fear included fear of infection, death, public criticism, family members getting infected, and economic loss. The subjective level of disruption in daily activities was measured using a 0-100 numeric rating scale developed by the Korea Disease Control and Prevention Agency. Multivariable linear regression was used to analyze the associations between the independent and dependent variables. A subgroup analysis was performed based on income level. @*RESULTS@#Participants who reported fear of infection (β=-3.37, p<0.001), death (β=-0.33, p=0.030), public criticism (β=-1.63, p<0.001), a family member getting infected (β=-1.03, p<0.001), and economic loss (β=-3.52, p<0.001) experienced more disturbances in daily activities. The magnitude of this association was most significant in the lowest-income group. @*CONCLUSIONS@#Individuals reporting COVID-19-related fear experienced higher levels of subjective disruption in daily activities.

The Ability to Rest at Home During COVID-19 Symptom Manifestation and Depressive Symptoms: Evidence From Korea

Objective@#This study investigated the association between ability to rest at home in times of coronavirus disease 2019 (COVID-19) symptom manifestation and depressive symptoms. @*Methods@#The 2020 Korea Community Health Survey data were used. The presence of depressive symptoms was determined using the Patient Health Questionnaire-9. The relationship between depressive symptoms and ability to rest at home was examined using logistic regression analysis. Additional analysis was performed on the reasons for the inability to stay at home. @*Results@#Depressive symptoms were more common in participants who could not rest at home if symptoms manifested (4.1%) than those who could rest at home (2.7%). Participants who could not rest at home (OR 1.53, 95% CI 1.34–1.74) were more likely to have depressive symptoms, particularly when they had to report to work (OR 1.50, 95% CI 1.30–1.74) or purchase daily necessities (OR 2.40, 95% CI 1.15–5.03). @*Conclusion@#Inability to rest at home in the case of COVID-19 symptom manifestation was associated with depressive symptoms. The findings suggest the need to address the identified vulnerable groups to mitigate the mental health consequences of the pandemic.

A Network Model of Positive Resources, Temperament, Childhood Trauma, and Comorbid Symptoms for Patient with Depressive Disorders

Objective@#Temperament, positive resources, childhood trauma, and other clinical comorbid symptoms are related to depressive symptom severity. Here, we used network analysis to examine the interrelations between these clinical factors in patients with depressive disorders. @*Methods@#Patients with depressive disorders (n=454) completed self-report questionnaires evaluating clinical symptoms, childhood trauma, temperament, and positive resources. To identify network pattern and the most central aspect, we performed network analysis and centrality analyses. First, we analyzed the network pattern in total participants. Second, we established two groups of those with severe depressive symptoms and those with mild depressive symptoms and compared their network patterns. @*Results@#Deficient optimism and depression were the central factors in the network of total participants. In the group with severe depressive symptoms, lack of social support and childhood emotional trauma showed high centrality. Deficient social support and other positive resources played central roles in the group with mild depressive symptoms. @*Conclusion@#Network pattern of psychological factors was different between those with mild or severe depression. Lack of positive resources is an important factor in psychological processes in both mild and severe depression. However, childhood emotional trauma may play a relatively important role in patients with severe depressive symptoms.

A Network Model of Positive Resources, Temperament, Childhood Trauma, and Comorbid Symptoms for Patient with Depressive Disorders

Objective@#Temperament, positive resources, childhood trauma, and other clinical comorbid symptoms are related to depressive symptom severity. Here, we used network analysis to examine the interrelations between these clinical factors in patients with depressive disorders. @*Methods@#Patients with depressive disorders (n=454) completed self-report questionnaires evaluating clinical symptoms, childhood trauma, temperament, and positive resources. To identify network pattern and the most central aspect, we performed network analysis and centrality analyses. First, we analyzed the network pattern in total participants. Second, we established two groups of those with severe depressive symptoms and those with mild depressive symptoms and compared their network patterns. @*Results@#Deficient optimism and depression were the central factors in the network of total participants. In the group with severe depressive symptoms, lack of social support and childhood emotional trauma showed high centrality. Deficient social support and other positive resources played central roles in the group with mild depressive symptoms. @*Conclusion@#Network pattern of psychological factors was different between those with mild or severe depression. Lack of positive resources is an important factor in psychological processes in both mild and severe depression. However, childhood emotional trauma may play a relatively important role in patients with severe depressive symptoms.

Why do some Korean parents hesitate to vaccinate their children? / 한국역학회지

OBJECTIVES@#Vaccinations for infectious diseases are opposed despite their achievement, and this opposition has recently been revealed in Korea. However, research in Korea has not been vigorous. The authors studied why some Korean parents hesitate to vaccinate their children by applying the health belief model.@*METHODS@#Parents who hesitate to vaccinate and parents who do not were surveyed in alternative education preschools and elementary schools. They were classified into four types of hesitancy and statistically compared.@*RESULTS@#Among the 129 subjects, 43 vaccinated without hesitancy, 20 vaccinated on time with hesitancy, 32 vaccinated with a deliberate delay of one month or longer, and 34 did not vaccinate. Vaccination increased with an increase in the awareness that severe outcomes can occur when unvaccinated. Concerns about adverse reactions from vaccinations or direct/indirect experiences affected refusal. Furthermore, perceptions of the lack of meaningfulness of vaccinations, distrust of policy and safety management, influence of leaders or activists in joined organizations, and experts of Korean traditional or alternative medicine affected refusal. Explanations by doctors, text messages and mails from institutions, and concerns about disadvantages caused by not complying with government policies increased vaccination.@*CONCLUSIONS@#The reasons for vaccine hesitancy and acceptance were similar to the results of international research. Health authorities and professionals should communicate sufficiently and appropriately with hesitant parents and find ways to rationally resolve social conflicts. However, this sample was small and there is little Korean research, so more in-depth and diverse researchs are needed.

Why do some Korean parents hesitate to vaccinate their children? / 한국역학회지

OBJECTIVES: Vaccinations for infectious diseases are opposed despite their achievement, and this opposition has recently been revealed in Korea. However, research in Korea has not been vigorous. The authors studied why some Korean parents hesitate to vaccinate their children by applying the health belief model. METHODS: Parents who hesitate to vaccinate and parents who do not were surveyed in alternative education preschools and elementary schools. They were classified into four types of hesitancy and statistically compared. RESULTS: Among the 129 subjects, 43 vaccinated without hesitancy, 20 vaccinated on time with hesitancy, 32 vaccinated with a deliberate delay of one month or longer, and 34 did not vaccinate. Vaccination increased with an increase in the awareness that severe outcomes can occur when unvaccinated. Concerns about adverse reactions from vaccinations or direct/indirect experiences affected refusal. Furthermore, perceptions of the lack of meaningfulness of vaccinations, distrust of policy and safety management, influence of leaders or activists in joined organizations, and experts of Korean traditional or alternative medicine affected refusal. Explanations by doctors, text messages and mails from institutions, and concerns about disadvantages caused by not complying with government policies increased vaccination. CONCLUSIONS: The reasons for vaccine hesitancy and acceptance were similar to the results of international research. Health authorities and professionals should communicate sufficiently and appropriately with hesitant parents and find ways to rationally resolve social conflicts. However, this sample was small and there is little Korean research, so more in-depth and diverse researchs are needed.

Why do some Korean parents hesitate to vaccinate their children? / 한국역학회지

OBJECTIVES: Vaccinations for infectious diseases are opposed despite their achievement, and this opposition has recently been revealed in Korea. However, research in Korea has not been vigorous. The authors studied why some Korean parents hesitate to vaccinate their children by applying the health belief model.METHODS: Parents who hesitate to vaccinate and parents who do not were surveyed in alternative education preschools and elementary schools. They were classified into four types of hesitancy and statistically compared.RESULTS: Among the 129 subjects, 43 vaccinated without hesitancy, 20 vaccinated on time with hesitancy, 32 vaccinated with a deliberate delay of one month or longer, and 34 did not vaccinate. Vaccination increased with an increase in the awareness that severe outcomes can occur when unvaccinated. Concerns about adverse reactions from vaccinations or direct/indirect experiences affected refusal. Furthermore, perceptions of the lack of meaningfulness of vaccinations, distrust of policy and safety management, influence of leaders or activists in joined organizations, and experts of Korean traditional or alternative medicine affected refusal. Explanations by doctors, text messages and mails from institutions, and concerns about disadvantages caused by not complying with government policies increased vaccination.CONCLUSIONS: The reasons for vaccine hesitancy and acceptance were similar to the results of international research. Health authorities and professionals should communicate sufficiently and appropriately with hesitant parents and find ways to rationally resolve social conflicts. However, this sample was small and there is little Korean research, so more in-depth and diverse researchs are needed.

Asymptomatic Middle East Respiratory Syndrome coronavirus infection using a serologic survey in Korea / 한국역학회지

OBJECTIVES@#The rates of asymptomatic infection with Middle East Respiratory Syndrome (MERS) coronavirus vary. A serologic study was conducted to determine the asymptomatic MERS infection rate in healthcare workers and non-healthcare workers by exposure status.@*METHODS@#Study participants were selected from contacts of MERS patients based on a priority system in 4 regions strongly affected by the 2015 MERS outbreak. A sero-epidemiological survey was performed in 1,610 contacts (average duration from exposure to test, 4.8 months), and the collected sera were tested using an enzyme-linked immunespecific assay (ELISA), immunofluorescence assay (IFA), and plaque reduction neutralization antibody test (PRNT). Among the 1,610 contacts, there were 7 ELISA-positive cases, of which 1 exhibited positive IFA and PRNT results.@*RESULTS@#The asymptomatic infection rate was 0.060% (95% confidence interval, 0.002 to 0.346). The asymptomatic MERS case was a patient who had been hospitalized with patient zero on the same floor of the hospital at the same time. The case was quarantined at home for 2 weeks after discharge, and had underlying diseases, including hypertension, angina, and degenerative arthritis.@*CONCLUSIONS@#The asymptomatic infection was acquired via healthcare-associated transmission. Thus, it is necessary to extend serologic studies to include inpatient contacts who have no symptoms.

Instruments to Assess Physical Impairments in Post-Intensive Care Syndrome: A Systematic Review / 중환자간호학회지

PURPOSE: The purpose of this study was to systematically review the instruments utilized to assess physical impairment in post-intensive care syndrome (PICS) of intensive care unit (ICU) survivors.METHOD: Online databases searched were MEDLINE, Cochrane, CINAHL, and Embase. Studies that met the following criteria were included: 1) the study population exclusively had experience with ICU admission; 2) the study assessed pulmonary, neuromuscular, and physical functions; and 3) the study was published in English language journals after 2007.RESULTS: A total of 56 instruments (2 pulmonary, 25 neuromuscular, 29 physical function) from 94 studies were reviewed. They were classified into self-report, observation, and measurement according to the type of assessment. No instrument measured all 3 areas of physical impairment. Five instruments were originally developed for the ICU patients. The most frequently applied instruments were the Medical Research Council and the 36-item Short Form Survey (physical component summary), which were used in 23 studies each. Only 13.8% of reviewed studies reported the reliability or validity of the instruments.CONCLUSION: Our results suggest that the appropriateness of instruments assessing physical impairment in PICS cannot be guaranteed. Despite the multidimensional concept of physical disabilities, most studies measured only one area, and studies that reported psychometric properties were limited. Accordingly, we propose to develop a unique and multifaceted instrument for ICU survivors.

Asymptomatic Middle East Respiratory Syndrome coronavirus infection using a serologic survey in Korea / 한국역학회지

OBJECTIVES: The rates of asymptomatic infection with Middle East Respiratory Syndrome (MERS) coronavirus vary. A serologic study was conducted to determine the asymptomatic MERS infection rate in healthcare workers and non-healthcare workers by exposure status.METHODS: Study participants were selected from contacts of MERS patients based on a priority system in 4 regions strongly affected by the 2015 MERS outbreak. A sero-epidemiological survey was performed in 1,610 contacts (average duration from exposure to test, 4.8 months), and the collected sera were tested using an enzyme-linked immunespecific assay (ELISA), immunofluorescence assay (IFA), and plaque reduction neutralization antibody test (PRNT). Among the 1,610 contacts, there were 7 ELISA-positive cases, of which 1 exhibited positive IFA and PRNT results.RESULTS: The asymptomatic infection rate was 0.060% (95% confidence interval, 0.002 to 0.346). The asymptomatic MERS case was a patient who had been hospitalized with patient zero on the same floor of the hospital at the same time. The case was quarantined at home for 2 weeks after discharge, and had underlying diseases, including hypertension, angina, and degenerative arthritis.CONCLUSIONS: The asymptomatic infection was acquired via healthcare-associated transmission. Thus, it is necessary to extend serologic studies to include inpatient contacts who have no symptoms.

Establishment of a chronic obstructive pulmonary disease mouse model based on the elapsed time after LPS intranasal instillation / 한국실험동물학회지

Chronic obstructive pulmonary disease (COPD) was the 3rd leading cause of death in 2012 worldwide. It is particularly severe in the elderly, who are at risk of death by coughing, mucous hypersecretion, and finally breathlessness. Recently, anti-COPD drug development has increased, and many animal screening systems have been studied. Tobacco smoke animal models are the best known animal screening system, but have several preparation requirements, such as a tobacco smoke generator and a separate facility to prevent smoke release. Accordingly, we evaluated the properties of a lipopolysaccharide (LPS) murine model for COPD screening and the effect of the time elapsed from 0 to 72 hr after LPS intranasal instillation on various biomarkers of COPD severity, such as WBC and neutrophils in bronchoalveolar fluid (BALF), IgE in serum, histopathology in the lung, and cytokines (IL-8, TNF-α, IFN-γ, and TGF-β) and chemokines (CCL-2, CXCL1, CXCL9, CXCL10, and CXCL11) in the respiratory system. Although from 48 hr after LPS treatment several factors which could be evaluated as biomarkers for COPD establishment such as WBC and neutrophil in BALF, IgE in serum, cytokines (IL-8, TNF-α, and IFN-γ), and chemokines (CCL-2, CXCL1, CXCL9, CXCL10, and CXCL11) increased at 72 hr the increment of important factors for COPD establishment such as IgE, fibrosis in the lung, and cytokines (IL-8, TNF-α, and IFN-γ) was more clear. Based on our results, we concluded that the optimal time after LPS intranasal instillation is 72 hr.

A Qualitative Research on Role Conflict Experiences of Clinical Dental Hygienists / 치위생과학회지

This study was based on the experience of dental hygienists' role conflict, and attempted to grasp the nature of the dental hygienist role conflict factor, constituent factor and coping. Giorgi's phenomenological method was used to analyze data collected through in-depth interviews with nine dental hygienists working in a dental clinic. The analysis revealed three central meanings: task scope, role conflicts, and role conflict management style and limitations. In the first category, task scope, the range of the legal scope, and the duties performed by the dental hygienist differed slightly. The second category included role conflict due to interpersonal relationship, work, work environment, competence, and identity as a professional because of role conflict. The third category included the role conflict management style and limitations. Dental hygienists tried to solve the role conflict situation through various efforts. In the face of the reality that the conflict is not solved despite such efforts, the dental hygienists felt the limitation and chose to leave. Dental hygienists are dissatisfied with their roles because of confusion regarding professional values and lack of awareness of the professional workforce due to differences between legal scope and actual practice. Based on the results of this study, it is necessary to develop a tool to quantitatively measure the level of role conflict in dental hygienists and to conduct follow-up studies on the effects of coping strategies by role conflict situations.

Asymptomatic Middle East Respiratory Syndrome coronavirus infection using a serologic survey in Korea / 한국역학회지

OBJECTIVES: The rates of asymptomatic infection with Middle East Respiratory Syndrome (MERS) coronavirus vary. A serologic study was conducted to determine the asymptomatic MERS infection rate in healthcare workers and non-healthcare workers by exposure status. METHODS: Study participants were selected from contacts of MERS patients based on a priority system in 4 regions strongly affected by the 2015 MERS outbreak. A sero-epidemiological survey was performed in 1,610 contacts (average duration from exposure to test, 4.8 months), and the collected sera were tested using an enzyme-linked immunespecific assay (ELISA), immunofluorescence assay (IFA), and plaque reduction neutralization antibody test (PRNT). Among the 1,610 contacts, there were 7 ELISA-positive cases, of which 1 exhibited positive IFA and PRNT results. RESULTS: The asymptomatic infection rate was 0.060% (95% confidence interval, 0.002 to 0.346). The asymptomatic MERS case was a patient who had been hospitalized with patient zero on the same floor of the hospital at the same time. The case was quarantined at home for 2 weeks after discharge, and had underlying diseases, including hypertension, angina, and degenerative arthritis. CONCLUSIONS: The asymptomatic infection was acquired via healthcare-associated transmission. Thus, it is necessary to extend serologic studies to include inpatient contacts who have no symptoms.

Effects of Organizational Culture of Dental Office and Professional Identity of Dental Hygienists on Organizational Commitment / 치위생과학회지

The purpose of this study was to identify the effect of dental hygienists' perceptions of dental organizational culture and professional identity on organizational commitment. A survey was conducted with 310 dental hygienists working in dental hospitals and dental offices. If dental hygienists experience organizational cultures as having different degrees of organizational commitment, then the type of organizational culture and commitment may be important variables in understanding and reducing the turnover rate of dental hygienists and improving workplace performance. Efforts to form a healthy and positive organizational culture may therefore be necessary. The organizational culture most recognized by the dental hygienist was hierarchical culture (3.39) and the least recognized was task-orientated culture (2.71). The professional identity of the dental hygienist was 3.75 and the organizational commitment was 2.98. Correlation analysis was conducted to investigate the relationship between dental organization culture type, professional dental hygienist identity, and organizational commitment. As a result, professional identity and organizational commitment showed positive(+) correlation with innovation oriented culture and relationship oriented culture. Among the organizational culture types, relationship-orientated culture (p<0.001) and innovation-orientated culture (p=0.006) were significant influences on organizational commitment, and professional identity did not have a significant influence. The regression model was found to be statistically appropriate (F=11.857, p<0.001) and the model explaining power was 14.9%. These results suggest that efforts to create a relationship-orientated culture and an innovation-orientated culture and to reduce the hierarchical culture can be a strategy to enhance the organizational commitment and the professional identity of dental hygienists.

Preventive behaviors by the level of perceived infection sensitivity during the Korea outbreak of Middle East Respiratory Syndrome in 2015 / 한국역학회지

OBJECTIVES: This study was performed to investigate the relationship between community residents’ infection sensitivity and their levels of preventive behaviors during the 2015 Middle East Respiratory Syndrome (MERS) outbreak in Korea. METHODS: Seven thousands two hundreds eighty one participants from nine areas in Gyeonggi-do including Pyeongtaek, the origin of the outbreak in 2015 agreed to participate in the survey and the data from 6,739 participants were included in the final analysis. The data on the perceived infection sensitivity were subjected to cluster analysis. The levels of stress, reliability/practice of preventive behaviors, hand washing practice and policy credibility during the outbreak period were analyzed for each cluster. RESULTS: Cluster analysis of infection sensitivity due to the MERS outbreak resulted in classification of participants into four groups: the non-sensitive group (14.5%), social concern group (17.4%), neutral group (29.1%), and overall sensitive group (39.0%). A logistic regression analysis found that the overall sensitive group with high sensitivity had higher stress levels (17.80; 95% confidence interval [CI], 13.77 to 23.00), higher reliability on preventive behaviors (5.81; 95% CI, 4.84 to 6.98), higher practice of preventive behaviors (4.53; 95% CI, 3.83 to 5.37) and higher practice of hand washing (2.71; 95% CI, 2.13 to 3.43) during the outbreak period, compared to the non-sensitive group. CONCLUSIONS: Infection sensitivity of community residents during the MERS outbreak correlated with gender, age, occupation, and health behaviors. When there is an outbreak in the community, there is need to maintain a certain level of sensitivity while reducing excessive stress, as well as promote the practice of preventive behaviors among local residents. In particular, target groups need to be notified and policies need to be established with a consideration of the socio-demographic characteristics of the community.

Factors affecting screening for diabetic complications in the community: a multilevel analysis / 한국역학회지

OBJECTIVES: The objective of the present study was to identify the factors that affect screening for diabetic complications by sex in the community. METHODS: This study used individual-level data from the 2013 Community Health Survey (CHS) for 20,806 (male, 9,958; female, 10,848) adults aged 30 years or older who were diagnosed with diabetes. Community-level data for 253 communities were derived from either CHS or national statistics. A chi-square test and multilevel logistic regression analysis was performed. RESULTS: There were significant differences in the rate of screening for diabetic complications according to individual-level and community-level variables. In the multilevel analysis, the community-level variance ratio of the null model was 7.4% and 9.2% for males and females, respectively. With regard to community-level variables, males were affected by the city type, number of physicians, and their living environment, while females were affected by number of physicians, natural and living environments, and public transportation. CONCLUSIONS: The factors that influenced individual willingness to undergo screening for diabetic complications differed slightly by sex; however, both males and females were more likely to undergo screening when they recognized their health status as poor or when they actively sought to manage their health conditions. Moreover, in terms of community-level variables, both males and females were affected by the number of physicians. It is essential to provide sufficient and ongoing opportunities for education on diabetes and its management through collaboration with local communities and primary care medical centers.

Evaluation report on the causal association between humidifier disinfectants and lung injury / 한국역학회지

OBJECTIVES: As of November 2011, the Korean government recalled and banned humidifier disinfectants (HDs) from the market, because four case-control studies and one retrospective epidemiological study proved the association between HDs and lung injury of unknown cause. The report reviewed the causal role of HDs in lung injury based on scientific evidences. METHODS: A careful examination on the association between the HDs and lung injury was based on the criteria of causality inference by Hill and the US Surgeon General Expert Committee. RESULTS: We found that all the evidences on the causality fulfilled the criteria (strength of association, consistency, specificity, temporality, biologic gradient, plausibility, coherence, experiment, analogy, consideration of alternative explanations, and cessation of exposure), which proved the unknown cause lung injury reported in 2011 was caused by the HDs. In particular, there was no single reported case of lung injury since the ban in selling HDs in November 2011 as well as before the HDs were sold in markets. CONCLUSIONS: Although only a few epidemiological studies in Korea have evaluated the association between lung injury and the use of HDs, those studies contributed to proving the strong association between the use of the HDs and lung injury, based on scientific evidence.

Thyroid cancer screening

The reported thyroid cancer incidence rate in Korea has been increasing by 24% per year for the past 10 years. If this were accurate, reducing the sharp increase in thyroid cancer would thus be an urgent public health concern. We cannot accurately estimate the proportion of over-diagnosis of thyroid cancer from screening. However, considering the lack of a notable change in the thyroid cancer mortality rate and that the thyroid incidence rate increased after introducing thyroid cancer screening, it is possible that the wider use of thyroid cancer screening could have been the primary contributor to the increase in the measured thyroid cancer incidence. Evidence on the benefits and harms of thyroid cancer screening is insufficient. To stabilize the thyroid cancer incidence, however, thyroid cancer screening programs for asymptomatic adults should be reconsidered except for screening high-risk individuals or for those prescribed through individual counseling by their physician.

Monitoring targets and indicators for the prevention and control of non-communicable diseases in Korea / 한국역학회지

In order to respond to the increasing burden of non-communicable diseases (NCDs) worldwide, the World Health Organization developed the global action plan (GAP), which included nine targets and 25 indicators to monitor the targets. Owing to space constraints, the article reviewed the status of 17 indicators for seven targets out of nine targets in the GAP in Korea. Most of these 17 indicators required additional analysis with existing national data to evaluate the status in Korea. Based on the result from evaluating indicators, the current NCD policy strategy and resources in Korea seemed unlikely to reach the GAP goals, unless innovative policy changes was planned to reduce NCD risk factors particularly focusing on smoking, excessive drinking, and insufficient physical activity.

Epidemiological investigation of the 119th confirmed Middle East Respiratory Syndrome coronavirus case with an indefinite mode of transmission during the Pyeongtaek outbreak in Korea / 한국역학회지

Since the first case was diagnosed on May 20, 2015, there were 186 confirmed cases of Middle East Respiratory Syndrome (MERS) until the end of outbreak in South Korea. Although medical institutions were the most identifiable sources of MERS transmission in South Korea, similar to other countries, in-depth epidemiological investigation was required for some confirmed cases with indefinite contact history or hospital visit records. The subject of epidemiological investigation in the present study was a 35 year-old male patient diagnosed with MERS (#119) who lived in Asan-city and worked in Pyeongtaek-city. Various potential sources of transmission were carefully investigated. While he could have been exposed to MERS through a friend from Saudi Arabia or confirmed MERS cases in his workplace, neighboring areas, and medical institutions, as well as contacts in his home, the chances of transmission were low; however, the potential for transmission through his local community could not be excluded. Practically, it was difficult to determine the modes of transmission for all outbreak cases in communicable disease that occurred in this short period of time. The investigation to identify the mode of transmission in this case was ultimately unsuccessful. However, the various data collected and analyzed to reveal modes of transmission provided detailed information that could not be collected using only interview surveys.