On Nov. 20, the U.S. Centers for Disease Control and Prevention confirmed three cases of swine-origin triple reassortant influenza A (H3N2) (S-OtrH3N2) virus infection in children in two counties in Iowa. None of the children were hospitalized, according to CDC, and each has recovered from a mild episode of respiratory illness. All three were in contact with one another, and none had a known recent exposure to swine.
No additional human infections with this virus have been detected in Iowa, and no evidence of sustained human-to-human transmission of this S-OtrH3N2 virus exists; surveillance is ongoing.
Eighteen human infections with swine-origin influenza A (H3N2) viruses have been identified since 2009 (1,2). The most recent 10 cases, including the three Iowa cases described in this report, were infections with S-OtrH3N2 viruses containing the matrix (M) gene from the pandemic 2009 influenza A (H1N1) virus (pH1N1).
These viruses are considered reassortant viruses between a swine-origin influenza A (H3N2) virus circulating in North American swine and a pH1N1 virus. All cases of human infection with S-OtrH3N2 virus containing the M gene from the pH1N1 virus have occurred in 2011 and have been reported from four states: Pennsylvania (three cases), Maine (two), Indiana (two), and Iowa (three) (3).
Read the report.