Accuracy of Rapid Antigen Screening Tests for SARS-CoV-2 Infection at Correctional Facilities in Korea: March - May 2022.

BACKGROUND: The number of confirmed cases of individuals with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection increased rapidly due to the Omicron variant. Correctional facilities are vulnerable to infectious diseases, and they introduced rapid antigen tests (RATs) to allow for early detection and rapid response. We aimed to evaluate the diagnostic performance and usefulness of SARS-CoV-2 RATs in newly incarcerated people. MATERIALS AND METHODS: We conducted a cross-sectional study at correctional facilities in Korea from 9 March to 22 May 2022. The study population was newly incarcerated people who were divided into two groups. In one group, 799 paired SARS-CoV-2 RATs and real-time polymerase chain reaction (RT-PCR) were conducted simultaneously in 522 individuals in March 2022. In the other group, 4,034 paired RATs and RT-PCR consecutively in 4,034 participants; only individuals with negative RATs results underwent RT-PCR from April to May 2022. We analyzed data using descriptive statistics and a logistic regression model. RESULTS: Among the 799 specimens in March, RT-PCR was positive in 72 (9.0%), and among the 4,034 specimens in April - May 2022, RT-PCR was positive in 40 (1.0%). Overall, the RATs had a sensitivity of 58.3%, specificity of 100.0%, positive predictive value (PPV) of 100.0%, and negative predictive value (NPV) of 96.0%. Asymptomatic individuals constituted 98.2% of the study group, and symptomatic individuals 1.8%. In asymptomatic cases, the sensitivity of RATs was 52.5%, specificity was 100.0%, PPV was 100.0%, and NPV was 96.3%. In symptomatic cases, the sensitivity of RATs was 84.6%, specificity was 100.0%, PPV was 100.0%, and NPV was 33.3%. Sensitivity (P = 0.034) and NPV (P = 0.004) differed significantly according to the presence and absence of symptoms, and the F1 score was the highest at 0.9 in symptomatic individuals in March. There was a positive linear trend in the proportion of false-negative RATs in newly incarcerated people following the weekly incidence of SARS-CoV-2 (P = 0.033). The best-associated predictors of RATs for SARS-CoV-2 infection involved symptoms, timing of sample collection, and repeat testing. CONCLUSION: Sensitivity and NPV significantly depend on whether symptoms are present, and the percentage of false negatives is correlated with the incidence. Thus, using RATs should be adjusted according to the presence or absence of symptoms and the incidence of SARS-CoV-2 infection in the community. RATs could be a useful screening tool as an effective first-line countermeasure because they can rapidly identify infectious patients and minimize SARS-CoV-2 transmission in correctional facilities.

The association mental health of adolescents with economic impact during the COVID-19 pandemic: a 2020 Korean nationally representative survey.

BACKGROUND: COVID-19 has affected innumerable aspects of life, including education, economy, and religion. Economic problems and inequality are associated with poor mental health in adolescents. This study aimed to identify the relationship between economic damage to families due to COVID-19 and various mental health problems in Korean adolescents and to evaluate the risk factors of mental health. METHODS: In total, 54,948 Korean adolescent students from 398 middle and 395 high schools were surveyed between August and November 2020. Complex sample logistic regression was performed to calculate odds ratios (ORs) and 95% confidence intervals (CI) for depression and suicidal ideation, respectively. A generalized linear model analysis was used to examine the association between mental health (unhappiness, loneliness, and stress) and the economic impact of COVID-19. Analyses were adjusted for age, gender, school grade, perceived academic achievement, perceived family economic status, and economic support. RESULTS: The ORs of depression (OR = 1.77, 95% CI:1.57-2.00), suicidal ideation (OR = 2.14, 95% CI:1.84-2.50), unhappiness (OR = 1.51 95% CI 1.42-1.60) and lonely (OR = 1.38 95% CI 1.27-1.49) for the low level of perceived family economic status was higher compared to middle level. Adolescents who experienced economic deterioration in their households as COVID-19 showed a higher risk of depression (OR = 1.42, 95% CI:1.35-1.49), suicide ideation (OR = 1.36, 95% CI:1.28-1.44), unhappiness (OR = 2.23 95% CI 2.19-2.27), lonely (OR = 1.20 95% CI 1.17-1.22), and stress (OR = 1.14 95% CI 1.12-1.16) than those who did not. CONCLUSIONS: The findings revealed an association between the decline in household economic status due to COVID-19 and mental health problems, such as stress, loneliness, suicidal ideation, depression, and unhappiness.

Early countermeasures to COVID-19 at long-term care facilities in Gwangju Metropolitan City, Republic of Korea.

OBJECTIVES: The coronavirus disease 2019 (COVID-19) pandemic has continued since its first detection in the Republic of Korea on January 20, 2020. This study describes the early countermeasures used to minimize the risk of COVID-19 outbreaks during cohort quarantine and compares the epidemiological characteristics of 2 outbreaks in long-term care facilities (LTCFs) in Gwangju Metropolitan City in summer 2020. METHODS: An epidemiological investigation was conducted via direct visits. We investigated epidemiological characteristics, including incidence, morbidity, and mortality rates, for all residents and staff members. Demographic characteristics were analyzed using a statistical program. Additionally, the method of managing infection in LTCFs is described. RESULTS: Residents and caregivers had high incidence rates in LTCF-A and LTCF-B, respectively. LTCF-B had a longer quarantine period than LTCF-A. The attack rate was 20.02% in LTCF-A and 27.9% in LTCF-B. The mortality rate was 2.3% (1/43) in LTCF-B, the only facility in which a COVID-19 death occurred. CONCLUSIONS: Extensive management requires contact minimization, which involves testing all contacts to mitigate further transmission in the early stages of LTCF outbreaks. The findings of this study can help inform and prepare public health authorities for COVID-19 outbreaks, particularly for early control in vulnerable facilities.

A Seroprevalence Study on Residents in a Senior Care Facility with Breakthrough SARS-CoV-2 Omicron Infection.

The Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) began spreading rapidly in the community in November 2021, becoming the dominant variant in the Republic of Korea in 2022. Although its pathogenesis in healthy individuals was low, the severity and hospitalization rate was higher in the elderly and immunocompromised patients. We aimed to investigate the immunogenicity in acute and convalescent phases of breakthrough infection by Omicron in elderly individuals. Serological data were assessed by electrochemiluminescence immunoassay, enzyme-linked immunosorbent assay, and plaque-reduction neutralization tests. SARS-CoV-2-specific antibody and immunoglobulin G levels in the acute phase were higher in third dose-vaccinated elderly than in first and second dose-vaccinated patients. The neutralization antibody titer was detected only in third dose-vaccinated patients, and the titer was higher for the Delta than the Omicron variant. In the convalescent phase of Omicron infection, the neutralization antibody titer of vaccinated patients was higher for the Delta than the Omicron variant except in unvaccinated individuals. We demonstrated that the cause of the vulnerability to Omicron variant infection in third dose-vaccinated elderly was due to the low neutralization antibody level against Omicron. A fourth dose of vaccination is required in the elderly to reduce hospitalization and mortality caused by the Omicron variant.

Clinical severity according to the primary infection variant in patients with suspected SARS-CoV-2 reinfection in Korea.

OBJECTIVES: We aimed to evaluate the severity of suspected severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reinfection according to variants of concern in Gyeongsangbuk-do and Daegu, Korea. METHODS: The database of coronavirus disease 2019 (COVID-19) cases reported from epidemiological investigations through the integrated system operated by the Korea Disease Control and Prevention Agency, from January 20, 2020 to May 7, 2022 was combined with data from the Health Insurance Review and Assessment Service system. The severity odds ratio (SOR) in secondary infection episodes compared with primary infection was estimated using a generalized linear model with a binomial distribution. RESULTS: In all patients, the SOR of SARS-CoV-2 reinfection was 0.89 (95% confidence interval [CI], 0.82 to 0.95), and the severity was lower than in the first infection. Patients who had been vaccinated within 91 days showed a more attenuated SOR (0.85; 95% CI, 0.74 to 0.98). However, despite vaccination, in patients with both primary and secondary infections caused by the Omicron variant, the severity was reduced to a lesser extent than in patients primarily infected with other variants. CONCLUSIONS: We could make efforts to relieve the severity of COVID-19 in vulnerable populations, in which death is more likely, by recommending booster vaccinations in case of a resurgence.

Time from Exposure to Diagnosis among Quarantined Close Contacts of SARS-CoV-2 Omicron Variant Index Case-Patients, South Korea.

To determine optimal quarantine duration, we evaluated time from exposure to diagnosis for 107 close contacts of severe acute respiratory syndrome coronavirus 2 Omicron variant case-patients. Average time from exposure to diagnosis was 3.7 days; 70% of diagnoses were made on day 5 and 99.1% by day 10, suggesting 10-day quarantine.

Community Transmission of SARS-CoV-2 Omicron Variant, South Korea, 2021.

In South Korea, a November 2021 outbreak caused by severe acute respiratory syndrome coronavirus 2 Omicron variant originated from 1 person with an imported case and spread to households, kindergartens, workplaces, restaurants, and hospitals, resulting in 11 clusters within 3 weeks. An epidemiologic curve indicated rapid community transmission of the Omicron variant.

The Association Between Organizational Justice and Health-Related Productivity Loss Among Korean Employees.

OBJECTIVES: To investigate the association between organizational justice (OJ) and health-related productivity loss (HRPL) among Korean employees. METHODS: From January 6, 2020 to February 18, 2020, data were collected using a web-based questionnaire. This study measured HRPL using the Work Productivity and Activity Impairment Questionnaire: General Health version. Procedural and interactional justice were measured using the Korean organizational justice questionnaire. Generalized linear models were used for estimating productivity loss based on tertiles of OJ levels, while the productivity loss of employees in low OJ categories was used as a reference group. RESULTS: The nonparametric associations between the OJ levels and the overall HRPL level were observed. High levels of OJ significantly reduced HRPL. CONCLUSIONS: Our results support the hypothesis that high OJ is associated with improved labor productivity.

mRNA vaccine effectiveness against SARS-CoV-2 B.1.617.2 (Delta) and B.1.1.529 (Omicron) variant transmission from home care cases to household contacts in South Korea.

OBJECTIVES: Household contacts of confirmed cases of coronavirus disease 2019 (COVID-19) areexposed to a high risk of viral transmission, and secondary incidence is an important indicatorof community transmission. This study analyzed the secondary attack rate and mRNA vaccineeffectiveness against transmission (VET) for index cases (patients treated at home) confirmedto be infected with the Delta and Omicron variants. METHODS: The subjects of the study were 4,450 index cases and 10,382 household contacts.Logistic regression analysis was performed to compare the secondary attack rate byvaccination status, and adjusted relative risk and 95% confidence intervals were identified. RESULTS: The secondary attack rate of the Delta variant was 27.3%, while the secondary attackrate of the Omicron variant was 29.8%. For the Delta variant, groups with less than 90 daysand more than 90 days after 2 doses of mRNA vaccination both showed a VET of 37%. For theOmicron variant, a 64% VET was found among those with less than 90 days after 2 doses ofmRNA vaccination. CONCLUSION: This study provides useful data on the secondary attack rate and VET of mRNAvaccines for household contacts of COVID-19 cases in South Korea.

The effectiveness of Paxlovid treatment in long-term care facilities in South Korea during the outbreak of the Omicron variant of SARS-CoV-2.

OBJECTIVES: On November 5, 2021, Pfizer Inc. announced Paxlovid (nirmatrelvir +ritonavir) asa treatment method that could reduce the risk of hospitalization or death for patients withconfirmed coronavirus disease 2019 (COVID-19). METHODS: From February 6, 2022 to April 2, 2022, the incidence of COVID-19 and the effectsof treatment with Paxlovid were analyzed in 2,241 patients and workers at 5 long-term carefacilities during the outbreak of the Omicron variant of severe acute respiratory syndromecoronavirus 2 in South Korea. RESULTS: The rate of severe illness or death in the group given Paxlovid was 51% lower thanthat of the non-Paxlovid group (adjusted risk ratio [aRR], 0.49; 95% confidence interval [CI],0.24-0.98). Compared to unvaccinated patients, patients who had completed 3 doses of thevaccine had a 71% reduced rate of severe illness or death (aRR, 0.29; 95% CI, 0.13-0.64) and a65% reduced death rate (aRR, 0.35; 95% CI, 0.15-0.79). CONCLUSION: Patients given Paxlovid showed a lower rate of severe illness or death and alower fatality rate than those who did not receive Paxlovid. Patients who received 3 dosesof the vaccine had a lower rate of severe illness or death and a lower fatality rate than theunvaccinated group.

Importation and Transmission of SARS-CoV-2 B.1.1.529 (Omicron) Variant of Concern in Korea, November 2021.

In November 2021, 14 international travel-related severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) B.1.1.529 (omicron) variant of concern (VOC) patients were detected in South Korea. Epidemiologic investigation revealed community transmission of the omicron VOC. A total of 80 SARS-CoV-2 omicron VOC-positive patients were identified until December 10, 2021 and 66 of them reported no relation to the international travel. There may be more transmissions with this VOC in Korea than reported.

The association of family structure with health behavior, mental health, and perceived academic achievement among adolescents: a 2018 Korean nationally representative survey.

BACKGROUND: Adolescence is a period during which physical, social, and mental abilities are rapidly developed, and during this time the family environment plays an important role. Differences in health behaviors, mental health, and academic achievement by family structure may affect future families, income, and employment. The purpose of the study was to investigate the association of family structure with health behaviors, mental health, and academic achievement in Korean adolescents. METHOD: Data from the 2018 Korean Youth Risk Behavior Web-based Survey were analyzed. The study sample was comprised of 59,096 adolescents. Logistic regression, t-tests, and a variance analysis of a complex sample general linear model were used to examine the association of family structure with health behaviors, mental health, and academic achievement. The significance level was set at P < 0.05. RESULTS: Non-intact families (single-mother families, single-father families, and restructured families) had significantly higher odds of smoking a cigarette, drinking a sip of alcohol, internet use, physical activity, and sexual experience, and mental health issues such as depression, suicidal ideation, perceived stress, and poor perceived health status than intact families (two-parent families). Also, non-intact families were significantly related to low perceived academic achievement compared to intact ones. CONCLUSION: This study showed that family structure is a significant factor in adolescent health behavior, mental health, and perceived academic achievement. Adolescents who experience a transition in their family structure may be more vulnerable to health risks and exhibit lower academic achievement than those in an intact family.

The Association between Organizational Justice and Psychological Well-Being by Regular Exercise in Korean Employees.

Many studies have shown that organizational justice (OJ) is related to psychological determinants of employees' physical and mental health in the workplace, and these health outcomes also lead to the psychological well-being (PW) of employees. Additionally, physical activity is one of the most important issues related to health in the workplace. This study compared the level of perceived OJ according to sociodemographic and lifestyle factors and examined the association between OJ and PW by regular exercise (hours per week) in Korean employees. This study used cross-sectional data obtained from 494 subjects in South Korea. Self-administered questionnaires comprising OJ, PW, and lifestyle factors (e.g., smoking, drinking, sleeping, and exercise) were completed by employees in April 2017. Multiple logistic regression analyses were conducted to estimate the association of procedural justice (PJ) and interactional justice (IJ) with the prevalence odds ratios and 95% confidence intervals of the high risk to PW. After the adjustment of sociodemographic characteristics and lifestyle factors, the main effects of PJ and IJ on the high risk to PW were significantly observed, and when these values were stratified by a regular exercise category, the lowest odds ratio was observed in a group that exercised for 1-2 h (hours per week). Organizations must encourage trust and consideration between employees and supervisors and carry out efforts to improve their environment, such as making the decision-making process fairer and encouraging employees to exercise regularly. This intervention may help prevent a high risk to PW.

Association of the Use of a Heated Tobacco Product with Perceived Stress, Physical Activity, and Internet Use in Korean Adolescents: A 2018 National Survey.

The awareness and use of the recently introduced heated product in the global tobacco market is rapidly increasing. Few studies have investigated the association of this product's use with health-related factors. To examine the association of the heated tobacco product (HTP)'s use with perceived stress, physical activity, and internet use, we analyzed data from the Korea Youth Risk Behavior Survey using multinomial logistic regression models. The participants included 60,040 students from middle school and high school. There were significant associations between high perceived stress and cigarette use only, dual use of cigarette and e-cigarette, triple use of cigarette, e-cigarette, and HTP; a negative association between HTP's use and perceived stress; positive association between physical activity and tobacco use; and not using the internet significantly increased the odds of use of all types of tobacco products. A smoking prevention program, tailored to meet the needs of different types of tobacco product users, is recommended. A program aimed at not only increasing awareness of perceived risk but also decreasing perceived benefits of risky behaviors, should also be considered. Further research using a longitudinal design to test the causal relationship of tobacco product use with perceived stress, physical activity, and internet use is warranted.

Reliability and validity of the Korean version of organizational justice questionnaire.

BACKGROUND: Many studies show that organizational justice (OJ) is related to psychological determinants of employee health. To prevent health problems related to OJ in Korean workplaces and to accurately measure OJ, we developed the Korean version of the Organizational Justice Questionnaire (K-OJQ) and assessed its validity and reliability. METHODS: A questionnaire draft of the K-OJQ was developed using back-translation methods, which was preliminary tested by 32 employees in Korea. Feedback was received and the K-OJQ was finalized. This study used data from 303 workers (172 males, 131 females) in Korea using the K-OJQ, job stress, and lifestyle questionnaires. RESULTS: Cronbach's α coefficients of the internal consistency reliability was 0.92 for procedural justice and 0.94 for interactional justice. Factor analyses using SPSS 24 and Amos 23 extracted two expected factors, named procedural justice (7 items; range, 1.0-5.0) and interactional justice (6 items; range, 1.0-5.0) and showed a reliable fit (χ2 = 182; p = .000; GFI = .912; AGFI = .877; CFI = .965; RMSEA = .077). Furthermore, higher procedural justice and interactional justice levels were correlated with lower job demand (- 0.33; - 0.36), insufficient job control (- 0.36; - 0.41), interpersonal conflict (- 0.45; - 0.51), job insecurity (- 0.33; - 0.34), organizational system (- 0.64; - 0.64), and lack of reward (- 0.55; - 0.63). CONCLUSIONS: The K-OJQ was objectively validated through statistical methods.