H5N1 Outbreaks in US Livestock and Human Case Investigation
H5N1 avian influenza continues to spread in US dairy & poultry. USDA reports new cases in a Texas dairy herd and South Dakota turkeys. A California pediatric case highlights the critical need for a One Health approach.
H5N1 Avian Influenza: Key Updates for Veterinarians & Public Health
The USDA (APHIS) has confirmed new H5N1 avian influenza outbreaks in U.S. livestock and poultry, underscoring the virus's persistent spread, while a human case in California emphasizes zoonotic transmission risks.
Key Points:
Texas Dairy Herd Infected: A Texas dairy herd has tested positive for H5N1, the state's first detection since May 2025. The national total now stands at 1,079 infected herds across 17 statessince early 2024.
Major Poultry Outbreaks: A new outbreak at a large commercial turkey operation in Beadle County, South Dakota (over 52,000 birds) was reported, alongside other recent cases in South Dakota and North Dakota poultry.
Human Case Investigation: CDC investigators published a report on a pediatric H5N1 case in California from December 2024. The child, infected with the B3.13 genotype found in cattle, had no clear exposure to poultry. Possible environmental sources are being investigated, with no evidence of human-to-human transmission.
One Health Approach Critical: The unexplained human case highlights the necessity of integrated animal and human health monitoring. Real-time surveillance and genomic sequencing are vital for tracking cross-species transmission.
Implications for Veterinarians:
Veterinary professionals are on the front lines. Vigilance for symptoms like unusual mortality, respiratory, or neurologic signs in dairy and poultry is essential. Veterinarians are critical for enforcing biosecurity measures, managing outbreak response, and collaborating with public health authorities to mitigate this zoonotic threat.
