Puppies are transmitting potentially deadly Campylobacter bacteria infections via contaminated poop to the humans who handle them, with 55 people now sickened in an outbreak reaching across 12 states.

In the latest update from the U.S. Centers for Disease Control and Prevention, the agency says cases rose from 39 in mid-September to 55 reported by Tuesday.

“Evidence suggests that puppies sold through Petland are a likely source of this outbreak,” the CDC said in a news release issued Sept 11. “Petland is cooperating with public health and animal health officials to address this outbreak.” Health Day (10/03)