FIG 2.

Summary of genotypic analysis of low-pathogenic H5 avian influenza A viruses detected in domestic poultry in the United States (2001 to 2017). Genotypes were assigned by unique combinations of sublineages for each gene, which were determined based on tree topology with a bootstrap value of ≥70 and a nucleotide sequence identity of ≥95%. To simplify the illustration, only the representative viruses were selected for each genotype, including those with unique combinations of location of detection (state/province) and year. Numbers on the tree indicate individual H5 low-pathogenic introductions and were linked to unique IDs of those introductions to the right.