I haven't heard much about bird flu the past couple of years. did the problem fade away?

No: It still pops up here and there, but fortunately has not affected large number of people; in good part due to continued vigilance and rapid culling of affected poultry.

Cyclic: Influenza changes year by year sometimes just very gradually that we call drift, sometimes wholescale change that we call shift. Recently many people have relative immunity to the current strains so it hasn't been bad. Each year that can change with a new strain becoming prevalent.