The US Centers for Disease Control and Prevention (CDC) today announced three variant influenza cases among fairgoers in North Dakota, Ohio, and Pennsylvania. Information about the cases appears in this week's FluView report.
The cases bring the number of novel flu infections reported this year to 19, all but 1 reported in the last 30 days.
The CDC said all three patients had contact with swine at agricultural fairs. At this time, two of the viruses have been fully characterized and are influenza A H3N2 variant (H3N2v) viruses.
The third virus has been characterized as an influenza A (H3) variant, and tests are under way to further characterize the virus. A variant influenza strain occurs when an influenza A virus that normally circulates in swine is detected in humans.
Four states now report cases
Texas, Ohio, North Dakota, and Pennsylvania are the only states to report variant strains this year, with Ohio reporting 15 H3 variant viruses and 1 H1N2 variant virus (the other states have reported one H3N2v case each).
Of the three cases announced today, two people attended the same fair. The Pennsylvania resident's exposure occurred out of state, according to FluView.
The North Dakota Department of Health released a statement on Aug 15 that said two people, one an out-of-state visitor, contracted the variant virus at the North Dakota State Fair in Minot.
Two of the three patients were hospitalized, and all three patients have fully recovered from their infections. One patient was older than 64; the other two were children.
H3N2v was first detected in humans in 2011.
In 2012, the CDC confirmed 309 US cases, most linked to exposure at swine exhibits. Last year, only 18 cases were reported.
Aug 18 CDC FluView
Aug 15 North Dakota Department of Health statement
Jul 28 CIDRAP News Story "CDC reports 11 H3N2v flu cases linked to Ohio fair"