As Sarah Avery reported for newsobserver.com, E. coli cases keep increasing in North Carolina. So far, 24 cases have been confirmed and 33 cases are being studied to see whether the cases are related.

The most common link among the people who are sick is a trip to the State Fair last month — in particular, to a petting zoo exhibit. Of the 33 cases under scrutiny, 15 have State Fair connections, one attended the Cleveland County fair, seven did not attend the fair and the remainder have not completed the investigator’s questionnaire.

“If it does turn out to be a petting zoo, there are thousands of people who were exposed, and they are widespread,” said Dr. Jeffrey Engel, state epidemiologist. “People came to visit from other states.”

The outbreak is North Carolina’s largest E. coli infection since a 2001 incident in Robeson County that stemmed from unpasteurized butter offered to schoolchildren during a demonstration. More than 200 grew sick.

Food contamination, particularly from beef that has come in contact with animal feces during slaughter and processing, is often the source of E. coli infections, but petting zoos are also common sources.

William Marler, a Seattle lawyer who has built a national practice filing lawsuits in E. coli and other contamination cases, said petting zoos are aware of the dangers of the business, and most provide hand-washing stations. But even the best of precautions can still fall short.

He said he represented 25 families in an unsuccessful Oregon case in which people grew ill after visiting the petting zoo. Half of the victims washed their hands; half didn’t. Babies in strollers got sick despite never getting out of their strollers or touching the animals.

“The frustrating thing was, there wasn’t a common denominator,” Marler said. “We were trying to figure out what the fair did or should’ve done to prevent the outbreak.”

He said two of the North Carolina families in the current outbreak have called him, but he does not know whether there is a legal case. Much depends on what state health investigators turn up and whether the outbreak is traced to the State Fair.

“When I was a kid taking my cow to the fair, nobody even heard of E. coli,” Marler said. “That was 35 years ago. But since Jack in the Box, and with repeated fair outbreaks, we have to be more vigilant.”