A fourth case of swine flu has been linked to the Minnesota State Fair, this one in a teenage boy who exhibited hogs at the Swine Barn.
The boy was at the fair Aug. 23-26 and became ill two days later after he went home, according to the Minnesota Department of Health. He did not require hospitalization.
All four cases linked to the fair so far involved patients who spent long hours in the Swine Barn, and all four recovered quickly. The four cases involved a strain of flu different from the one that prompted national warnings in August.
Minnesota health officials went on high alert last month as the new strain swept across the central Midwest, sickening more than 300 people, with most cases linked to agricultural fairs.
The new strain, H3N2, has resembled ordinary seasonal flu, with symptoms that include a fever and runny nose. But public health officials watched it carefully because the flu virus can mutate quickly once it jumps from one species to another.
Two cases of that flu, and a suspected third case, were reported last month in Dakota County among people who attend a live-animal market.
All four cases linked to the State Fair involved a different strain, known as H1N2.