Objectives: In May 2025, clusters of salmonellosis were identified in 7 cities in the Republic of Korea, all associated with consumption of identical bakery products. This investigation aimed to characterize the outbreak, identify potential contributing factors, and inform strategies for preventing similar multi-facility foodborne outbreaks. Methods: A case series study was conducted among individuals who consumed Manufacturer H’s Product I and Product II on May 15–16, 2025 at 7 facilities (n = 1,235). Clinical specimens from symptomatic individuals, retained food samples, and environmental samples were collected and tested. Food-exposure histories were assessed, and active case finding was implemented across all supplied facilities. Traceback investigations were conducted at the manufacturer, distributor, and egg farms. Human and food isolates underwent pulsed-field gel electrophoresis (PFGE) and whole-genome sequencing (WGS). Results: A total of 323 cases met the outbreak case definition (attack rate, 26.2%), of which 48 were laboratory-confirmed. Salmonella Enteritidis was isolated from both clinical specimens and retained bakery products. PFGE patterns were indistinguishable between human and food isolates, and WGS demonstrated high genetic relatedness. These findings confirmed a common-source outbreak linked to the implicated bakery products. Conclusion This outbreak underscores the value of integrating epidemiological investigation, active case finding, and molecular typing to identify common food vehicles in outbreaks involving widely distributed manufactured foods. Coordinated collaboration between public health and food safety authorities is essential for the effective detection, response, and prevention of multi-facility foodborne outbreaks.

Objective: This study compared the incidence of suicide cases among Korean students before and after the coronavirus disease-2019 (COVID-19) pandemic. Methods: Aggregated case reports of all known suicide victims attending elementary, middle, and high school in South Korea from 2017 to 2022 were analyzed. These reports, compiled by teachers under the directive of the South Korean Department of Education, surveyed the circumstances surrounding each suicide and identified associated risk factors posthumously. Results: The completed suicide rate was 2.37 per 100,000 students pre-COVID-19 (2017–2019), significantly increasing to 3.37 per 100,000 students post-COVID-19 (2020–2022; odds ratio [OR] 1.42, p<0.001). The rate began to rise approximately 6 months into the pandemic and continued to worsen throughout 2021 and 2022. Fair attendance significantly increased in 2020 (74.83%, p=0.003) during the initial stage of school closure measures compared to 2019 (58.27%) among students prior to suicide completion. However, as social distancing measures continued, “absence due to medical reasons” showed a significant increase in 2022 (23.56%) compared to 2019 (13.67%, p=0.025) and 2020 (9.52%, p<0.001) among these students. Among those who completed suicide, teachers reported increased signs of depression and anxiety posthumously compared to pre-COVID-19 periods. Conclusion The incidence of completed suicide among students was significantly higher in the post-COVID-19 years compared to pre-COVID-19. Attendance records and teachers’ reports indicated a deterioration in mental health among these students before suicide completion, highlighting the need to consider mental health impacts when implementing future quarantine policies.

Objective: This study compared the incidence of suicide cases among Korean students before and after the coronavirus disease-2019 (COVID-19) pandemic. Methods: Aggregated case reports of all known suicide victims attending elementary, middle, and high school in South Korea from 2017 to 2022 were analyzed. These reports, compiled by teachers under the directive of the South Korean Department of Education, surveyed the circumstances surrounding each suicide and identified associated risk factors posthumously. Results: The completed suicide rate was 2.37 per 100,000 students pre-COVID-19 (2017–2019), significantly increasing to 3.37 per 100,000 students post-COVID-19 (2020–2022; odds ratio [OR] 1.42, p<0.001). The rate began to rise approximately 6 months into the pandemic and continued to worsen throughout 2021 and 2022. Fair attendance significantly increased in 2020 (74.83%, p=0.003) during the initial stage of school closure measures compared to 2019 (58.27%) among students prior to suicide completion. However, as social distancing measures continued, “absence due to medical reasons” showed a significant increase in 2022 (23.56%) compared to 2019 (13.67%, p=0.025) and 2020 (9.52%, p<0.001) among these students. Among those who completed suicide, teachers reported increased signs of depression and anxiety posthumously compared to pre-COVID-19 periods. Conclusion The incidence of completed suicide among students was significantly higher in the post-COVID-19 years compared to pre-COVID-19. Attendance records and teachers’ reports indicated a deterioration in mental health among these students before suicide completion, highlighting the need to consider mental health impacts when implementing future quarantine policies.

Objective: This study compared the incidence of suicide cases among Korean students before and after the coronavirus disease-2019 (COVID-19) pandemic. Methods: Aggregated case reports of all known suicide victims attending elementary, middle, and high school in South Korea from 2017 to 2022 were analyzed. These reports, compiled by teachers under the directive of the South Korean Department of Education, surveyed the circumstances surrounding each suicide and identified associated risk factors posthumously. Results: The completed suicide rate was 2.37 per 100,000 students pre-COVID-19 (2017–2019), significantly increasing to 3.37 per 100,000 students post-COVID-19 (2020–2022; odds ratio [OR] 1.42, p<0.001). The rate began to rise approximately 6 months into the pandemic and continued to worsen throughout 2021 and 2022. Fair attendance significantly increased in 2020 (74.83%, p=0.003) during the initial stage of school closure measures compared to 2019 (58.27%) among students prior to suicide completion. However, as social distancing measures continued, “absence due to medical reasons” showed a significant increase in 2022 (23.56%) compared to 2019 (13.67%, p=0.025) and 2020 (9.52%, p<0.001) among these students. Among those who completed suicide, teachers reported increased signs of depression and anxiety posthumously compared to pre-COVID-19 periods. Conclusion The incidence of completed suicide among students was significantly higher in the post-COVID-19 years compared to pre-COVID-19. Attendance records and teachers’ reports indicated a deterioration in mental health among these students before suicide completion, highlighting the need to consider mental health impacts when implementing future quarantine policies.

Objective: This study compared the incidence of suicide cases among Korean students before and after the coronavirus disease-2019 (COVID-19) pandemic. Methods: Aggregated case reports of all known suicide victims attending elementary, middle, and high school in South Korea from 2017 to 2022 were analyzed. These reports, compiled by teachers under the directive of the South Korean Department of Education, surveyed the circumstances surrounding each suicide and identified associated risk factors posthumously. Results: The completed suicide rate was 2.37 per 100,000 students pre-COVID-19 (2017–2019), significantly increasing to 3.37 per 100,000 students post-COVID-19 (2020–2022; odds ratio [OR] 1.42, p<0.001). The rate began to rise approximately 6 months into the pandemic and continued to worsen throughout 2021 and 2022. Fair attendance significantly increased in 2020 (74.83%, p=0.003) during the initial stage of school closure measures compared to 2019 (58.27%) among students prior to suicide completion. However, as social distancing measures continued, “absence due to medical reasons” showed a significant increase in 2022 (23.56%) compared to 2019 (13.67%, p=0.025) and 2020 (9.52%, p<0.001) among these students. Among those who completed suicide, teachers reported increased signs of depression and anxiety posthumously compared to pre-COVID-19 periods. Conclusion The incidence of completed suicide among students was significantly higher in the post-COVID-19 years compared to pre-COVID-19. Attendance records and teachers’ reports indicated a deterioration in mental health among these students before suicide completion, highlighting the need to consider mental health impacts when implementing future quarantine policies.

The impact of Streptococcus pneumoniae coinfection on coronavirus disease 2019 (COVID-19) prognosis remains uncertain. We conducted a retrospective analysis of patients hospitalized with COVID-19 who underwent a pneumococcal urinary antigen (PUA) test to assess its clinical utility. Results showed that PUA-positive patients required more oxygen support, high-flow nasal cannula, and dexamethasone compared to PUA-negative patients.Furthermore, the significantly higher incidence of a National Early Warning Score ≥5 in the PUA-positive group (P<0.001) suggests that a positive PUA test is associated with a severe disease course. However, no significant difference in mortality was observed between the two groups, and antibiotics were used in almost all patients (96.2%). While the PUA test may help guide antibiotic use in COVID-19 patients, its interpretation should be approached with caution.

The impact of Streptococcus pneumoniae coinfection on coronavirus disease 2019 (COVID-19) prognosis remains uncertain. We conducted a retrospective analysis of patients hospitalized with COVID-19 who underwent a pneumococcal urinary antigen (PUA) test to assess its clinical utility. Results showed that PUA-positive patients required more oxygen support, high-flow nasal cannula, and dexamethasone compared to PUA-negative patients.Furthermore, the significantly higher incidence of a National Early Warning Score ≥5 in the PUA-positive group (P<0.001) suggests that a positive PUA test is associated with a severe disease course. However, no significant difference in mortality was observed between the two groups, and antibiotics were used in almost all patients (96.2%). While the PUA test may help guide antibiotic use in COVID-19 patients, its interpretation should be approached with caution.

Objective: This study compared the incidence of suicide cases among Korean students before and after the coronavirus disease-2019 (COVID-19) pandemic. Methods: Aggregated case reports of all known suicide victims attending elementary, middle, and high school in South Korea from 2017 to 2022 were analyzed. These reports, compiled by teachers under the directive of the South Korean Department of Education, surveyed the circumstances surrounding each suicide and identified associated risk factors posthumously. Results: The completed suicide rate was 2.37 per 100,000 students pre-COVID-19 (2017–2019), significantly increasing to 3.37 per 100,000 students post-COVID-19 (2020–2022; odds ratio [OR] 1.42, p<0.001). The rate began to rise approximately 6 months into the pandemic and continued to worsen throughout 2021 and 2022. Fair attendance significantly increased in 2020 (74.83%, p=0.003) during the initial stage of school closure measures compared to 2019 (58.27%) among students prior to suicide completion. However, as social distancing measures continued, “absence due to medical reasons” showed a significant increase in 2022 (23.56%) compared to 2019 (13.67%, p=0.025) and 2020 (9.52%, p<0.001) among these students. Among those who completed suicide, teachers reported increased signs of depression and anxiety posthumously compared to pre-COVID-19 periods. Conclusion The incidence of completed suicide among students was significantly higher in the post-COVID-19 years compared to pre-COVID-19. Attendance records and teachers’ reports indicated a deterioration in mental health among these students before suicide completion, highlighting the need to consider mental health impacts when implementing future quarantine policies.

The impact of Streptococcus pneumoniae coinfection on coronavirus disease 2019 (COVID-19) prognosis remains uncertain. We conducted a retrospective analysis of patients hospitalized with COVID-19 who underwent a pneumococcal urinary antigen (PUA) test to assess its clinical utility. Results showed that PUA-positive patients required more oxygen support, high-flow nasal cannula, and dexamethasone compared to PUA-negative patients.Furthermore, the significantly higher incidence of a National Early Warning Score ≥5 in the PUA-positive group (P<0.001) suggests that a positive PUA test is associated with a severe disease course. However, no significant difference in mortality was observed between the two groups, and antibiotics were used in almost all patients (96.2%). While the PUA test may help guide antibiotic use in COVID-19 patients, its interpretation should be approached with caution.

Objectives: In March 2023, an alternative school in the Republic of Korea reported 12 cases of shigellosis. This study aims to analyze the epidemiological characteristics in order to determine the cause of the cluster outbreak of shigellosis and to develop prevention strategies. Methods: This study focused on 12 patients with confirmed Shigella infection and investigated their demographics, clinical features, epidemiology, diagnostics, and antimicrobial susceptibility. Following the identification of Shigella, we conducted follow-up rectal smear cultures to manage patients, implementing isolation and control measures. Results: This study investigated the emergence of multidrug-resistant Shigella following missionary activities in Cambodia, documenting a cluster infection within an alternative school in Daejeon, the Republic of Korea. The outbreak affected 56 participants, resulting in the confirmation of 12 cases. The incidence rates varied by gender and occupation, with higher rates among males and teachers. All 12 cases demonstrated multidrug resistance. Challenges included delayed pathogen confirmation and suboptimal adherence to isolation criteria. The incident prompted revisions in the criteria for isolation release, focusing on symptom resolution. The study underscores the necessity for strengthened surveillance, educational initiatives focusing on prevention in endemic areas, and improved oversight of unlicensed educational establishments. Conclusion Successful response strategies included swift situation assessment, collaborative efforts, effective infection control measures, and modified criteria for isolation release. Continued surveillance of multidrug-resistant strains is recommended, especially in regions with a high prevalence.