Since 1997 a new and more deadly strain of highly pathogenic avian influenza virus (A/H5N1) has appeared in domestic poultry and humans, initially in southern China where the first human-to-human transmission took place.
Leta 1997 se je pojavil nov in bolj smrtonosen sev visoko patogenega virusa aviarne influence (A/H5N1) pri domači perutnini in ljudeh, najprej v južni Kitajski, kjer je prišlo do prvega prenosa s človeka na človeka.