Additional swine-origin H3N2 influenza cases reported

The U.S. Centers for Disease Control and Prevention recently announced the existence of two additional cases of swine-origin H3N2 influenza.

In both of the cases, one in Maine, the other in Indiana, the patient had recent exposure to pigs, according to CIDRAP News.

The new cases bring the number of H3N2 infections in the United States containing the M gene from the 2009 H1N1 virus to seven. There is no evidence of any link between the seven patients or of any human-to-human transmission.

Six of the total patients reportedly had direct contact with pigs prior to infection. The seventh had a caretaker who had been exposed to the animals.

The CDC said that it is monitoring the implications of the genetic change, which was most likely the result of a swine coinfection with H3N2 and the 2009 H1N1 virus, CIDRAP News reports. The agency said that it would continue to try to identify possible transmission and reduce further exposure, but added that most novel influenza viruses do not result in human-to-human transmission.

The Indiana Department of Health announced that its laboratory identified the virus in late October and forwarded it to the CDC, which confirmed the triple reassortant H3N2 virus through genome testing. No additional illnesses were reported in the patient’s household or among close contacts.