WASHINGTON - Health officials are urging people to be cautious at agricultural fairs this summer after the Centers for Disease Control and Prevention reported an increase in the number of swine flu cases linked to pigs at such fairs.

The CDC said there were 12 new cases of the H3N2v virus in the past week in Hawaii, Ohio and Indiana, and all were linked to people who attended or exhibited swine at an agricultural fair.

Washington-area officials suggest those at high risk for the flu - including children, the elderly, pregnant women and those with weak immune systems - avoid exposure to pigs at county fairs as the annual fair season hits its peak.

"We just want to get ahead of the curve, as these things do tend to spread," said Peter Beilenson, the health officer for Howard County, Md., which issued an alert Saturday. "We're not trying to raise hysteria. We're trying to make sure people avoid getting sick."

Health officials pay close attention to swine flu cases: Strains of the virus caused a pandemic in 2009 that led to thousands of deaths in the United States, according to the CDC. There were mass vaccinations and shortages of the vaccine.

August is the traditional time of state and county fairs, where attendees can count on fried foods, cotton candy, carnival rides and animal exhibitions. Some Maryland fairs have gotten rid of petting zoos, in part to avoid the spread of animal-carried diseases, especially to young children, who would be most likely to handle the animals.

Martin Svrcek, executive director of the Montgomery County Agricultural Fair, said safety is his most important priority for the fair.

"As our urbanized society has moved farther from farms, many folks who are city dwellers have not developed the same kind of immunities that farmers or people who have been around farms have," Svrcek said.

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