The News-Observer ran an article a few days ago about 3-year-old Matthew Baldwin, who picked up a nearly deadly case of E. coli from a 45-minute visit to the petting zoo in October. Matthew was the first of more than 100 people sickened by E. coli last month after attending the North Carolina State Fair.
From the article:

William D. Marler, a personal injury lawyer in Seattle who specializes in contamination cases, said petting zoos are increasingly being identified as sources of E. coli outbreaks. He said the Centers for Disease Control and Prevention has published suggestions to cut exposure, such as providing hand-washing stations with running water and soap — an amenity that wasn’t offered at the State Fair’s petting zoos.

Exhibits that fail to take such measures, Marler said, may carry some legal liability, and four North Carolina families have contacted him.

“I don’t think we, as the public and people in positions of authority, have taken this seriously,” Marler said. “Maybe five years ago nobody really knew about this, and it was novel. But it’s far more than novel at this point. There are dozens of outbreaks that have occurred in petting zoos and fairs.

“We have to get past the thought that we’re not going to do anything because fairs are part of Americana. If these were Ferris wheel accidents year in and year out, the public would go crazy.”