Also known as Swine flu triggered by the influenza A/H1N1 virus. The rapid human-to-human transmission is characteristic. Originally transmitted from pigs to humans, the virus carries both human and animal (birds, pigs) genes. In March 2009, the influenza A/H1N1 virus was described for the first time and, since then, is considered a great potential pandemic threat.
See also Influenza A virus