H5N1 Genetics

The first known strain of HPAI A(H5N1) (called A/chicken/Scotland/59) killed two flocks of chickens in Scotland in 1959; but that strain was very different from the current highly pathogenic strain of H5N1. The dominant strain of HPAI A(H5N1) in 2004 evolved from 1999 to 2002 creating the Z genotype.[11] It has also been called "Asian lineage HPAI A(H5N1)". Asian lineage HPAI A(H5N1) is divided