Health officials in Indiana said Wednesday that they had confirmed 113 cases of the new H3N2 swine flu, affecting people from 18 counties statewide.
That's a dramatic rise in new cases since last week, when the U.S. Centers for Disease Control and Preventionreported that one Indianan — and 11 people in Hawaii and Ohio — had recently been sickened with the flu strain. The virus has been passing from sick pigs to people visiting agricultural fairs, the CDC said, and is far more common in children than in adults, who may have some resistance to it from past outbreaks.
While the illness this H3N2 flu causes is relatively mild, similar to a typical seasonal flu, officials are watching the flu carefully for signs that it is adapting and becoming more contagious to people. The virus contains a version of one particular gene, the M gene, that scientists believe may make it transmit more easily in humans. The same version of the M gene is present in the 2009 pandemic H1N1 flu.
In a statement, the Indiana State Department of Health said that health investigators in the state had not yet found cases of the disease in which it passed from human to human but would continue to keep watch. The department cautioned that more cases of the new swine flu were expected to be confirmed this week.