The amino acid identities between genotype 3 and 4 were 83–87%, 89–94% and 75–87% in ORFs 1–3 respectively, while those between strains within genotype 3 were 94–98%, 96–99% and 93–100%, and within genotype 4 were 94– 99%, 93–99.8% and 83–100% in ORFs 1–3 respectively.