INDIANAPOLIS (AP) — State health officials are keeping a watch out for signs of the swine flu at county and 4H fairs in Indiana after four people became sick with the H3N2v influenza A after visiting the Grant County Agricultural Fair.

The state health department says there were 138 cases of that strain reported in Indiana last year. Two of the people who became ill in Grant County had contact with swine. Health officials say human infections with H3N2v are rare but have most commonly occurred after being near live infected pigs.

The State Board of Animal Health says 13 pigs at the fair tested positive for H3N2.

State Health Commissioner William VanNess says people who attend fair should wash their hands frequently and avoid taking food near areas where animals are kept.