PHWR Public Health Weekly Report

Objectives: Japanese encephalitis (JE) is a viral infectious disease primarily transmitted by Culex tritaeniorhynchus, with approximately 10–20 human cases reported annually in the Republic of Korea (ROK). The Korea Disease Control and Prevention Agency conducts annual surveillance to monitor vector mosquito occurrence and trends. This study aimed to evaluate the seasonal occurrence and regional distribution patterns of JE vector mosquitoes based on 2025 surveillance data.
Methods: In 2025, JE vector surveillance was conducted across 64 regions in the ROK. This study analyzed data from 12 provincial Health and Environment Institutes, where black light traps were installed at cattle barns. The trap index (individuals/traps/days) was calculated to compare seasonal patterns and regional differences in Cx. tritaeniorhynchus abundance. In addition, genetic analysis was performed to detect the JE virus in mosquito samples.
Results: A total of 22 mosquito species belonging to 8 genera were identified. The overall trap index was 251.2, with a Cx. tritaeniorhynchus trap index of 67.4. Seasonal occurrence of Cx. tritaeniorhynchus was concentrated between July and September, with a peak in the 36th week. Southern regions showed earlier emergence and higher densities, whereas northern regions showed delayed emergence and lower densities.
Conclusions: In 2025, the trap index for Cx. tritaeniorhynchus decreased by 34.8% compared to the previous year and by 9.1% relative to the 2022–2024 average year. This reduction was likely associated with climatic conditions, including a higher-than-normal summer mean temperature (25.7°C; +2.0°C above normal) and heavy rainfall in mid-July (200–700 mm), which may have affected mosquito survival and breeding. Continuous and high-resolution surveillance is essential for effective JE prevention, particularly in the context of climate change.

Objectives: Antimicrobial resistance is increasing worldwide. In particular, the rising incidence of infections caused by Carbapenem-resistant Enterobacterales (CRE), which have limited treatment options, has been identified as an important public health threat. This report aimed to analyze the characteristics of CRE infections in the Chungcheong region in 2024 and discuss their public health implications.
Methods: This analysis was based on CRE infection cases reported through the Korea Disease Control and Prevention Agency’s integrated infectious disease surveillance system from 2020 to 2024.
Results: In 2024, a total of 2,454 CRE infection cases were reported in the Chungcheong region. The proportion of individuals aged 70 years and older showed a yearly increasing trend, rising from 62.7% (459 cases) in 2020 to 69.4% (1,702 cases) in 2024. By type of healthcare institution, general hospitals accounted for the largest proportion of reported cases at 51.7% (1,269 cases), while long-term care hospitals accounted for 16.1% (394 cases), which were identified for the first time in 2024. Among Carbapenemase-producing CRE (CP-CRE) infections, Klebsiella pneumoniae was the most frequently detected species, accounting for 66.4% of cases, and the most commonly identified carbapenemase gene type was Klebsiella pneumoniae carbapenemase, accounting for 78.7% of cases.
Conclusions: Since CRE infections were designated as a nationally notifiable infectious disease in the Republic of Korea in 2017, the number of reported cases in the Chungcheong region has increased annually, and the proportion of CP-CRE infections has also risen. In particular, the initially reported cases in long-term care hospitals highlight the importance of infection prevention and control in these facilities. Active cooperation among medical institutions, local governments, and the central government is required to strengthen CRE infection surveillance and response.

Objectives: The Korea Disease Control and Prevention Agency (KDCA) conducts response training to evaluate collaboration among local governments (metropolitan and local), and related agencies for the rapid and effective management of emerging and re-emerging infectious diseases. This study aims to analyze the operational outcomes of the 2025 response training, and propose strategies for improvement.
Methods: Conducted across 17 metropolitan and provincial governments nationwide, the training program included four key areas: theoretical education on infectious diseases, functional exercises, tabletop exercises, and personal protective equipment training. Program effectiveness was evaluated through institutional assessments, individual participant-level evaluations and post-training satisfaction surveys.
Results: A total of 1,043 participants from 531 institutions participated in the training. Post-training evaluation demonstrated an enhanced understanding of response procedures and confirmed the effectiveness of interagency collaboration was confirmed. Overall, satisfaction survey results were positive.
Conclusions: Response training for emerging and re-emerging infectious diseases is crucial for strengthening local governments’ field response capacity and assessing interagency collaboration. KDCA is going to strengthen response capacity of the local government by supporting training budget and by providing new scenarios.