Human cases of swine influenza A (H1N1) virus infection have been identified in the U.S. in San Diego County and Imperial County, California as well as in San Antonio, Texas.
Internationally, human cases of swine influenza A (H1N1) virus infection have been identified in Mexico.
Swine Influenza (swine flu) is a respiratory disease of pigs caused by type A influenza that regularly cause outbreaks of influenza among pigs. Swine flu viruses do not normally infect humans, however, human infections with swine flu do occur, and cases of human-to-human spread of swine flu viruses has been documented.
From December 2005 through February 2009, a total of 12 human infections with swine influenza were reported from 10 states in the United States. Since March 2009, a number of confirmed human cases of a new strain of swine influenza A (H1N1) virus infection in California, Texas, and Mexico have been identified. An investigation into these cases is ongoing.
Investigations are ongoing to determine the source of the infection and whether additional people have been infected with similar swine influenza viruses.
CDC is working very closely with state and local officials in California, Texas, as well as with health officials in Mexico, Canada and the World Health Organization.
Source: Centers for Disease Control and Prevention, USA