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 Fridays by 9 a.m. ET.
- Total PCR tests run at NAHLN and NVSL (since April 2024): >76,900
- Pre-movement tests conducted under the Federal Order: 20,195
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?
10/04/24 | U.S. Government Highly Pathogenic Avian Influenza Research Priorities (193.55 KB)
9/24/24 | APHIS Releases National Epidemiologic Brief: Highly Pathogenic Avian Influenza H5N1 Genotype B3.13 in Dairy Cattle
This report provides field epidemiologic summaries using data collected from epidemiologic questionnaires for H5N1-affected dairy herds. View the report. (2.71 MB)