The Tennessee Department of Health is investigating multiple cases of residents who fell ill from consuming raw milk.

The health department launched the investigation after confirming two Chattanooga-area cases of cryptosporidiosis, a gastrointestinal disease from a parasite that lurks in contaminated water or unpasteurized milk. Both cases are linked to a dairy cow share program, which the state legalized in 2009, allowing greater access to raw milk.

“Consuming raw milk in the belief it’s healthier than pasteurized milk is a perilous risk that shakes off the possibility of a range of serious and occasionally fatal illnesses for the individuals and anyone they share it with,” John Dreyzehne, TDH commissioner, said in a news release. “Our best choice for healthy, nutritious milk is the pasteurized kind. Even if one believes there are health benefits, an upside, is it worth gambling on the downside risk of a serious illness, especially in a child?”

Since the state legalized cow share programs, reports have increased of disease and outbreaks linked to raw milk consumption. In 2013, nine Tennessee children became extremely sick with E. coli after drinking raw milk. Five of those required hospitalization and three developed severe, life-threatening kidney problems.