Data from: A brief history of bird flu

In 1918, a strain of influenza A virus caused a human pandemic resulting
in the deaths of 50 million people. A century later, with the advent of
sequencing technology and corresponding phylogenetic methods, we know much
more about the origins, evolution and epidemiology of influenza epidemics.
Here we review the history of avian influenza viruses through the lens of
their genetic makeup: from their relationship to human pandemic viruses,
starting with the 1918 H1N1 strain, through to the highly pathogenic
epidemics in birds and zoonoses up to 2018. We describe the genesis of
novel influenza A virus strains by reassortment and evolution in wild and
domestic bird populations, as well as the role of wild bird migration in
their long-range spread. The emergence of highly pathogenic avian
influenza viruses, and the zoonotic incursions of avian H5 and H7 viruses
into humans over the last couple of decades are also described. The threat
of a new avian influenza virus causing a human pandemic is still present
today, although control in domestic avian populations can minimize the
risk to human health.