Videos Show Spread of Swine Flu

By analyzing the mutations in swine flu samples, scientists have assembled the most complete model to date of the pandemic’s birth.

Traditional modeling — the pins-on-a-map approach — relies on formal reports of a disease. Although these convey the big picture, they don’t always give a clear picture of how the disease spread.

But because flu viruses constantly pick up genetic mutations as they multiply, scientists can deduce a family tree by comparing the shared ancestry of their genomes. This helps reveal hidden information about the spatial spread of the virus.

The researchers ran 242 viral genomes, collected around the world between late March and mid-July, through algorithms that determined their most likely evolutionary path. From hundreds of trillions of possible configurations, the program arrived at the models below.

The bottom video below is newer, but doesn’t clearly show swine flu spread outside North America. The top video above is older and contains fewer data points, but gives a more complete sense of the virus’ global jumps.





Original article here.