The present group of flu viruses that exist in present bird populations is only a few amino acids different from the 1918 Spanish Flu that killed an at least 50 million people around the world. This is the conclusion of research conducted by Yoshihiro Kawaoka of the University of Wisconsin-Madison and colleagues. The study was published in the June 11, 2014, edition of the journal Cell Host & Microbe.
The researchers examined the genetic code of all the known varieties of flu virus that are known to exist in modern birds. The study included domesticated fowl and wild birds. The researchers found that many of the flu viruses that are in modern bird populations are very similar to the strain of flu that caused the 1918 Spanish Flu pandemic. The differences in some instances are as small as two amino acid units. There are eight known flu species that fit the criteria for becoming a pandemic disease at present.
Flu viruses, like all other organisms, survive through adaptation. Climate changes, changes in environment, and association with other species can produce the necessary impetus to produce an addition of an amino acid or a rearrangement of the amino acids in flu viruses. Drugs can also produce the needed drive to adapt in flu viruses. Changes in flu virus DNA is most common in birds because birds, particularly migratory species, see a large variety of environments, associate with larger numbers of other species, and have been documented to be flu virus carriers.
The researchers suggest that a pandemic flu virus could emerge in the near future. The worst case scenario would be the mutation of a flu virus that is lethal in humans and easily transmitted between humans. The researchers support the continued international efforts to monitor bird flu and changes in the genetics of all known bird flu species in order to prevent a pandemic. If a virulent species of flu is detected rapidly enough then a pandemic can be avoided.