To better understand the epidemiology of SARS‐CoV‐2 reinfections, we analyzed national data from South Korean who were followed longitudinally from January 2020 to April 2022. We conducted a nationwide retrospective cohort study to estimate possible SARS‐CoV‐2 reinfection rates in all residents in South Korea, with at least two episodes of laboratory‐confirmed SARS‐CoV‐2 infection by reverse‐transcriptase polymerase chain reaction or rapid antigen test (RAT) performed at least 45 or more days between both episodes, between January 2020 and April 2022. There were 16 130 855 laboratory‐confirmed SARS‐CoV‐2 cases in South Korea, with 55 841 (346.2 per 100 000; or 0.3% of all infections) cases of possible reinfections. The reinfection rate has increased from 6.0 cases per 100 000 during Pre‐Delta period to 128.0 cases per 100 000 and 355.1 cases per 100 000 during Delta and Omicron periods, respectively. Persons with one dose of vaccination had the highest reinfection rate of 642.2 per 100 000, followed by unvaccinated persons (536.2/100 000) and two‐dose vaccinated persons (406.3/100 000). Our finding suggests that the majority of possible reinfections occurred following the emergence of new variants.

Background/Objectives: Pertussis continues to pose a substantial global health challenge despite widespread vaccination programs. This study aimed to analyze the epidemiological characteristics of recent pertussis cases in the Gyeongnam region of South Korea. Methods: We analyzed 419 pertussis cases in the Gyeongnam region of South Korea between October 2023 and April 2024, using data collected from epidemiological investigation reports, medical records, and interviews with health officials and school staff. Results: Our analysis revealed a distinct age distribution pattern with minimal cases in infants (0.2% under 1 year) and young children (7.9% in ages 1–6 years), while school-aged children showed the highest incidence (31.8% in ages 7–9 years, 36.0% in ages 10–12 years). The outbreak pattern demonstrated a progressive shift from preschool and elementary school students to middle and high school students. The time from symptoms onset to diagnosis varied significantly across age groups, with a median of 3.0 days (1.0–6.0) overall; notably, this was longer in high school students at 5.0 days (2.3–8.0) (p = 0.023). While 92.4% (365/395) of cases were fully vaccinated, substantial delays were observed in third and fourth dose administration (18.2% and 25.8%, respectively), with considerable timing variability for the fifth and sixth doses. Conclusions: Our findings highlight the changing epidemiology of pertussis in South Korea, characterized by an age shift toward older children. These results emphasize the need for enhanced surveillance focusing on school-aged populations and the reassessment of vaccination strategies, particularly regarding booster dose timings and adherence.

Objectives: It is crucial to establish the characteristics of coronavirus disease 2019 (COVID-19) outbreaks at army training centers to develop preventive measures. Therefore, this study aimed to determine the COVID-19 transmission patterns and risk factors in a sequence of outbreaks at an army training center from June to August 2021.Methods: This study included 1,324 trainees at an army training center where outbreaks occurred from June to August 2021. The outbreak was qualitatively analyzed according to the period, attack rate, demographic characteristics, vaccination history, and living areas. An aerodynamic experiment was performed to evaluate aerosol transmission in living areas.Results: Three outbreaks occurred at the army training center from June to August 2021. The first, second, and third outbreaks lasted for 32, 17, and 24 days, and the attack rates were 12.8%, 18.1%, and 8.9%, respectively. Confirmed cases were distributed in all age groups. Recruits and the unvaccinated were at higher risk for COVID-19. The aerodynamic experiment verified the possibility of aerosol transmission within the same living area.Conclusion: COVID-19 transmission at army training centers should be minimized through quarantine and post-admission testing during the latency period as part of integrated measures that include facility ventilation, vaccination, indoor mask-wearing, and social distancing.

이정헌, 조유진, 박신영, 김성순. Public Health Weekly Report 2025;18:1595-613. https://doi.org/10.56786/PHWR.2025.18.42.2

Antimicrobial resistance (AMR) is a major public health threat that causes treatment failures and increases mortality. However, appropriate antimicrobial use and improved awareness can prevent most cases of AMR. This article highlights the importance of awareness-building in preventing and managing AMR. It also introduces international examples of efforts to raise awareness of AMR and summarizes key national awareness-raising activities. A comprehensive review of major international websites, extant literature, national public awareness campaigns, AMR prevention materials, and recent survey findings on public awareness and behaviors was conducted. The awareness survey revealed a persistent gap between knowledge about antibiotic use and actual behavior. Nevertheless, a positive trend was observed: exposure to information that raises awareness resulted in tangible behavioral changes. In particular, healthcare professionals are highly trusted; thus, expert recommendations represent a valuable foundation that can direct citizens toward appropriate practices. This finding suggests that proactive expert-led communication should accompany public information dissemination to effectively prevent AMR. AMR is a preventable public health threat. Systematic and sustained awareness-raising activities can establish a critical foundation that promotes appropriate antibiotic use and reinforces national AMR response policies. The continued expansion of evidence-based, targeted communication strategies and multisectoral collaborations is essential for effective AMR prevention and control.

김선태, 엄지은, 이혁진, 조유진, 강슬기, 이동한, 이상은. Public Health Weekly Report 2025;18:277-95. https://doi.org/10.56786/PHWR.2025.18.6.1