The Centers for Disease Control and Prevention (CDC) is reporting a human infection with a novel influenza A virus was reported by the state of Michigan. The person was infected with an influenza A (H3N2) variant (H3N2v) virus and was hospitalized in June 2015 as a result of their illness, but has fully recovered. No human-to-human transmission has been identified and the case reported close contact with swine in the week prior to illness onset.
In July, a Minnesota resident was reported infected with an influenza A (H3N2) variant (H3N2v) virus.
Since December 2005, 354 cases of H3N2v have been reported in the US.
The CDC describes variant influenza viruses as follows:
When an influenza virus that normally circulates in swine (but not people) is detected in a person, it is called a “variant influenza virus.” For example, if a swine origin influenza A H3N2 virus is detected in a person, that virus will be called an “H3N2 variant” virus or “H3N2v” virus.
Most commonly, human infections with variant viruses have occurred in people exposed to infected pigs (e.g. children near pigs at a fair or workers in the swine industry). In addition, there have been documented cases of multiple persons becoming sick after exposure to one or more sick pigs. Also cases of limited person-to-person spread of variant viruses have occurred.