Characteristics of Animal Influenza Outbreaks and Human Infection Prevention Response Outcomes in the Honam Region,...

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.

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.

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.

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.