State health officials are investigating a cluster of salmonella cases in the Twin Cities, and say anyone who has consumed raw milk and fallen ill should alert them.

At least five children, aged between 3 months and 10 years, have tested positive for the bacteria Salmonella Typhimurium, according to a release from the Minnesota Department of Health. One child was hospitalized.

Health officials connected the cases to unpasteurized milk because two families said their children had drank it, and the other three children were infected with identical bacteria, indicating all the cases came from the same source, according to the release.

Pasteurization heats milk to the point of destroying bacteria or other pathogens. Unpasteurized milk, sometimes called raw milk, may contain germs because animals could carry infections that don’t harm them but do harm humans, or because the milk is contaminated with poop, according to the Centers for Disease Control.

“Even healthy animals can carry these germs and have them in their milk,” Maria Bye, senior epidemiologist in the Zoonotic Diseases Unit at MDH, said in a statement. “Consuming any unpasteurized milk is risky, no matter how clean the operation from which it is purchased.”

People can be sickened both by raw milk and by products made from it, like ice cream and soft cheeses, according to the CDC. The agency also warns that people can become sick from raw milk products even if they have consumed them from the same source in the past without illness.

CDC estimates there are some 1.35 million salmonella infections each year in the United States, mostly from food.

Symptoms of the strain of salmonella in the Twin Cities cluster of cases include diarrhea, cramps and fever, and last between four and seven days. Children under 5, adults over 65 and people with compromised immune systems are particularly susceptible.

MDH is still working to find the source of the milk that sickened these children, and asks anyone who became sick after drinking unpasteurized milk in late June or early July to fill out a confidential online survey or to email [email protected].