The U.S. Department of Agriculture, Food and Drug Administration, Centers for Disease Control and Prevention, and State veterinary and public health officials are investigating cases of highly pathogenic avian influenza (HPAI) in dairy cows.
APHIS is providing confirmatory testing for samples from livestock and keeping pace with the latest science on HPAI. As the situation changes, we will continue to post updated information below.
Latest Updates
Testing and Genetic Sequencing
Testing at National Animal Health Laboratory Network (NAHLN) and National Veterinary Services Laboratories (NVSL) is complex; the number of tests conducted is not equivalent to animals tested. The testing figure may include multiple samples collected from a single animal, samples tested independently or pooled, samples tested more than once, and testing for purposes such as on-farm research studies to continue to learn more about this virus in livestock. As such, the number of affected herds provides a much more accurate picture of the evolving situation than the number of tests conducted.
Testing information is updated weekly on Wednesdays by 4 p.m. ET.
- Total PCR tests run at NAHLN and NVSL (since April 2024): >50,800
- Pre-movement tests conducted under the Federal Order: 13,015
Genetic Sequencing
USDA makes genetic sequences from the U.S. H5N1 clade 2.3.4.4b influenza virus, including those from samples associated with the dairy cattle event, available on GISAID (the Global Initiative on Sharing Avian Influenza Data) and the National Center for Biotechnology Information (NCBI) Sequence Read Archive (use search term “WGS of H5N1”).
We post this information—first in raw format and then curated as the sequences are interpreted and quality checked in light of epidemiological information—in the interest of public transparency and ensuring the scientific community has access to this information as quickly as possible to encourage disease research and development.
Testing Resources
Science Updates
What's New?
8/28/24 | CVB Notice 24-13: Field Studies with Nonviable, Non-replicating Veterinary Vaccines Targeting Highly Pathogenic Avian Influenza in Livestock
8/15/24 | USDA Provides Information on Second Retail Sampling Survey
The U.S. Food and Drug Administration (FDA) has released the results of the second retail sampling survey of retail dairy products. The second sampling survey, coordinated with USDA for the analyses, tested 167 dairy products collected at retail locations for highly pathogenic avian influenza A (H5N1). Learn more.
8/13/24 | FSIS To Start H5N1 Beef Monitoring Sampling
On September 16, 2024, USDA's Food Safety and Inspection Service (FSIS) will be adding H5N1 influenza A monitoring in dairy cows at slaughter to its already robust national surveillance programs for pathogens and chemical contaminants. This initiative is part of USDA's ongoing efforts and research to verify the safety of the meat supply in the context of H5N1. Learn more.
Previous Updates
| Date | Title |
|---|---|
| 7/17/24 | Cow “Challenge” Study Should Help Turn Tables on H5N1 in Dairy Herds |
| 6/9/24 | 2024 HPAI H5N1: Michigan Dairy Herd and Poultry Flock Summary (561.9 KB) |
| 6/8/24 | HPAI H5N1 Genotype B3.13 in Dairy Cattle: National Epidemiologic Brief (959.43 KB) |