PHWR Public Health Weekly Report

Objectives: Human infections with avian influenza (AI) have been reported in multiple countries; however, no cases have been identified to date in the Republic of Korea. To prevent human AI infection, the Korea Disease Control and Prevention Agency (KDCA) summarized response outcomes from domestic AI outbreaks during the 2023–2024 season to provide a foundation for more effective preparedness and response policies.
Methods: Before the 2023–2024 AI season, KDCA revised response guidelines and strengthened the capacity of local AI response personnel. In addition, the Central AI Human Infection Response Task Force was established to prepare for potential domestic AI outbreaks.
Results: During the 2023–2024 season, surveillance identified a total of 31 cases of highly pathogenic AI in poultry and 19 cases in wild birds. A total of 3,986 individuals, including culling workers, farm workers, and AI response personnel, were classified as high-risk groups for human infection. These individuals underwent 10 days of active surveillance, and no suspected or symptomatic cases requiring further investigation were identified.
Conclusions: The risk of human AI infection continues to increase due to the emergence of new viral subtypes and confirmed AI infections in mammals. In response, KDCA will continue to strengthen collaboration with relevant agencies and enhance surveillance systems to support comprehensive disease control measures and ensure the continuous improvement of the national response framework.

Objectives: This report describes the epidemiological characteristics of animal influenza (AI) outbreaks and the features of high-risk human populations in the Honam region during the 2024–2025 epidemic season. It also aims to identify limitations observed in field responses and to propose areas for improvement to inform future strategies for the prevention and control of human AI infections.
Methods: AI detection data from animal health authorities were examined according to pathogenicity, occurrence site, and administrative district, with monthly trends derived from specimen collection dates. High-risk individuals were identified using exposure investigation forms reported to national infectious disease information system, and were evaluated by occupation, age, and nationality. Suspected human cases were reviewed for clinical manifestations, epidemiologic links, and results of real-time reverse transcription polymerase chain reaction (RT-PCR) testing.
Results: A total of 184 AI events were documented in the Honam region. Jeonbuk and Jeonnam primarily exhibited poultry farm–associated cases, whereas Gwangju predominantly showed cases associated with live bird markets. Initial detections occurred among wild birds, followed by a peak in poultry farm outbreaks in December. A total of 2,961 high-risk individuals were identified; over 80% were culling workers and 61.5% were foreign nationals. Four suspected human cases were recorded, all of which tested negative by RT-PCR.
Conclusions: During the 2024–2025 epidemic season, AI outbreaks in the Honam region increased in scale compared with previous seasons, and occurrence patterns and the size of the high-risk population were closely associated with outbreak magnitude. Although no human AI infections were identified, the predominance of culling workers and the high proportion of foreign workers among high-risk groups, along with inadequate implementation of preventive measures, highlighted vulnerabilities in field-level response capacity. These findings call for strengthened information sharing between animal and human health authorities before the epidemic season, systematized culling procedures, enhanced multilingual education for foreign workers, and advanced stockpiling of preventive resources for high-risk populations.