Health officials have linked a potentially deadly E. coli (search) outbreak to a third Florida fair, saying Thursday that DNA tests showed the organism may have infected people who attended the Florida State Fair in Tampa.

Officials say 22 people — mostly children in central Florida — are confirmed to have been infected by a particular strain of the E. coli bacteria and some of them have developed a potentially fatal follow-up disease affecting the kidneys.

Most attended the Central Florida Fair in Orlando or the Strawberry Festival in Plant City in March, but Health Secretary John Agwunobi said at least one person is believed to have contracted the infection at the fair in Tampa in mid-February.

Agwunobi also said officials are becoming convinced that the outbreak probably resulted from contact with farm or other types of animals at petting zoos, because it's the only common element between all three fairs.

While other causes haven't been ruled out, one company, Ag-Venture Farm Shows of Plant City, provided the animals for the petting zoos at all three, Agwunobi said.

The company has not returned calls from The Associated Press. Health officials say the company is cooperating with the Department of Agriculture in the investigation, and the animals who were at the three fairs have been voluntarily quarantined.

In addition to the 22 confirmed cases, officials are monitoring 33 suspected cases in Florida, 24 of them involving children.

So far, no one has died from the outbreak, although some are hospitalized with a very serious disease known as hemolytic uremic syndrome that is caused by toxins associated with the initial E. coli infection.

Health officials said Thursday that a girl who died last week in Pasco County was not infected with the disease as previously feared.