H5N1 Avian Flu Returns, Impacting Poultry Operations in the U.S.
In September, the H5N1 avian flu has made a significant resurgence across commercial poultry farms in the United States, particularly affecting turkey operations in Minnesota and the Dakotas. Following a summer marked by little activity, the poultry industry is facing renewed challenges as various facilities report outbreaks of the virus.
Recent Outbreaks in the U.S.
The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) recently reported that four poultry operations experienced H5N1 outbreaks just last week. Among these, three were commercial turkey and duck producers, with two outbreaks occurring in Stearns County, Minnesota, where a combined total of over 108,000 birds were impacted. Additionally, a commercial duck breeding operation in Indiana saw 24,300 birds affected, while a smaller backyard facility in Boone County, Iowa lost 140 birds.
This month alone, there have been 14 confirmed cases among commercial flocks and seven among backyard operations, resulting in the loss of approximately 620,000 birds nationwide. Notably, Minnesota has emerged as the epicenter of the avian flu crisis, with eight commercial and three backyard flocks affected, totaling around 338,650 birds. Outbreaks across facilities in North and South Dakota have also exacerbated the situation, impacting another 176,900 birds.
Increasing Infection Rates
The rolling total of affected birds has sharply increased after hitting a seasonal low of 150,000 in August. In the past 30 days alone, the prevalence of H5N1 has skyrocketed, alarming poultry farmers and industry experts alike. The return of the flu has raised concerns about biosecurity measures and the potential economic impact on the poultry sector.
Moreover, the number of detected cases among wild birds has also risen, consistent with fall migration trends. APHIS reported around 40 new detections in the past week, including a notable group of Blue-winged teal in Kansas that were harvested by hunters. Such findings highlight the interconnectedness between wild and domestic bird populations and the ongoing risks posed by the avian flu.
Global Developments in H5N1 Cases
On the international front, Cambodia recently reported its sixth human case of H5N1 in 2026, further intensifying concerns about the virus’s transmission. Cambodia has documented a total of 40 human cases of H5N1 since the beginning of the year. The latest individual, a 49-year-old man, remains hospitalized after contracting the virus on September 27 due to direct contact with infected poultry on a farm.
Since 2023, most human cases in Cambodia have involved a reassorted virus strain, presenting a mixture between the older H5N1 clade present since 2014 and a newer variant circulating globally. Alarmingly, these cases have shown a 40% case-fatality rate, underscoring the serious health implications of the avian flu beyond the poultry industry.
In summary, the H5N1 virus is causing significant disruptions across poultry operations in the U.S. while also posing a persistent threat to public health in regions like Cambodia. The situation demands ongoing vigilance and immediate action to mitigate further spread, protect both livestock and human populations, and ensure the sustainability of the poultry industry.