The Ministry of Environment (Minister Kim Wansup) announced that it has analyzed the status of highly pathogenic avian influenza (AI) outbreaks in domestic wild birds during the past winter (2024-2025) and plans to implement customized quarantine measures for the upcoming winter (2025-2026) by introducing scientific forecasting techniques to enable early detection of highly pathogenic AI.

The Ministry analyzed cases of highly pathogenic AI that occurred over a six-month period from October last year to March this year at major migratory bird habitats nationwide, following the downgrade of the AI a.lert level from “Caution” to “Attention” as of June 13, 2025.

As a result, a total of 43 cases of highly pathogenic AI were con.firmed in South Korea during the past winter (2024-2025) in wild bird-related samples, including 26 from carcasses, 12 from feces, and 5 from captured birds.

This represents a 2.3-fold increase compared to the same period the previous year, which recorded 19 cases (12 from carcasses, 5 from feces, and 2 from captured birds). 

The Ministry analyzed the following factors as reasons for the increase in cases of highly pathogenic AI compared to the previous year.

First, the initial outbreak date of the highly pathogenic AI virus (H5N1) last winter (October 14, 2024) was more than a month earlier than the initial outbreak date the previous winter (November 27, 2023) resulting in a longer period for the virus to spread.

In addition, the number of surveillance activities*, such as carcass collection and feces sampling, increased by more than 10% compared to the previous year. The Ministry’s collaboration with countries like Mongolia and Japan to share real-time migratory bird movement data and utilize global positioning system (GPS) tracking to predict migratory routes in advance for targeted feces sampling also contributed to the increased detection of the virus compared to previous years.

* Number of surveillance activities: (2023-2024) 20,640 cases, (2024-2025) 23,131 cases  

In particular, during the past winter, there was a more than 10% increase (based on the monthly peak population) in the number of Anatidae (duck family) birds, known to have a high potential for spreading AI, arriving* in Korea compared to the previous year. In addition, the global rise in AI cases**, including in Japan and Europe, also contributed to the increase.

* Status of wintering migratory birds (Anatidae species) based on simultaneous nationwide surveys at 200 major wetlands by the National Institute of Biological Resources: Winter 2023-2024: 883,281 birds → Winter 2024-2025: 989,310 birds (Approximately a 1.1-fold increase)

** (Japan) Winter 2023-2024: 156 cases → Winter 2024-2025: 226 cases (approximate 1.4x increase),

(Europe) Winter 2023-2024: 884 cases → Winter 2024-2025: 1,835 cases (approximate 2.1x increase)

The Ministry predicts that highly pathogenic AI is likely to continue spreading during the upcoming winter (2025-2026) and plans to strengthen quarantine measures in coordination with related agencies, such as the Ministry of Agriculture, Food and Rural Affairs, in line with the migratory routes and arrival periods* of wintering birds. 

* Typically, migratory routes of wintering birds follow paths such as Europe and the Americas ↔ the Arctic, Siberia, Mongolia, Alaska ↔ Korea, Japan. In South Korea, bird populations usually peak in December and decrease in February. (However, this year, the highest population was recorded in February)

Accordingly, this year the wild bird surveillance period will be extended by one month compared to the previous year, running from September 2025 to April 2026. The number of surveillance sites will also be increased from 92 to 102, and the number of nationwide simultaneous winter bird surveys will be expanded from 8 to 10 times annually.

In addition, the Ministry, through its affiliated agency, the National Institute of Wildlife Disease Control and Prevention, has developed a spatiotemporal predictive modeling technique* to forecast the occurrence and spread of AI in wild birds. This model will be applied to quarantine surveillance starting in the second half of this year.

* Development of a predictive modeling technique (July 2024-May 2025) based on domestic and international wild bird AI outbreaks, migratory bird habitat status, and land cover maps, to forecast timing and regional spread risk.

In addition, the Ministry plans to systematically manage highly pathogenic AI by pilot-operating mobile negative-pressure cages and holding and isolation modules* that can separate and analyze potentially infected individuals from the general population.

* Suspected infected individuals will be isolated from the general population to prevent the external leakage and spread of viruses. The system was developed by the National Institute of Wildlife Disease Control and Prevention in May this year and will be pilot-operated at the Chungnam Wild Animal Rescue Center starting in September 2025.

Kim Tae-oh, Director General for the Nature Conservation Bureau stated, “Avian influenza can affect not only wild birds but also poultry such as ducks and chickens, so we will further strengthen rapid information sharing and cooperation with related agencies, including the Ministry of Agriculture, Food and Rural Affairs.” He added, “This winter, we will do our utmost to prevent the domestic introduction of highly pathogenic avian influenza through advanced surveillance and international cooperation, thereby preventing zoonotic diseases and protecting farms.”