A novel swine-origin influenza A virus — H3N2 variant — has sickened 29 people since July 2011, including 16 in the past few weeks, the CDC confirmed in a press briefing on Friday. CDC epidemiologist Joseph Bresee called the 29 cases “a significant increase in the number of detections for these types of virus we’ve seen in recent years.”
All 16 recent cases had known contact with swine; however, 3 cases occurring in November 2011 suggested human-to-human transmission. None of the 16 recent cases required hospitalization; the 3 from November 2011 did. In all 29 patients, the H3N2 variant contained a gene from the 2009 pandemic virus that “may confirm increased transmissibility to and among humans compared with other variant influenza viruses,” Bresee said.
Since most swine contact occurred during agricultural fairs, Bresee stressed the importance of taking precautions in such settings (e.g., wash your hands before and after exposure to animals; don’t put anything in your mouth while in animal areas).