FIG 1.

Temporal distribution of swine H1N1pdm in France. The H1N1pdm viruses detected in pigs in France are individually represented by triangles positioned on the time x axis (graduated monthly from April 2009 to January 2018). The first H1N1pdm virus isolated from a mammalian animal in France, i.e., a cat, is represented by a black star. The lines represent the weekly numbers (y axis) of influenza A viruses (dotted line) and H1N1pdm viruses (black full line) detected in humans in France during this period. Human data were extracted from the World Health Organization (WHO)/Global Influenza Surveillance and Response System (GISRS) database (www.who.int/flunet).