The state health department said Monday it had not determined the source of the bacteria. But a Boone County health spokeswoman say three of the patients, including a 2-year-old, reported drinking raw dairy products.
The department says the 2-year-old was hospitalized and a 17-month-old developed life-threatening complications affecting the kidneys.
The St. Louis Post-Dispatch reports (http://bit.ly/IvI3xJ ) health officials said the other cases are in Cooper and Howard counties and it's not known if raw milk is connected to those cases.
Health officials also say more cases of E. coli might be are suspected and might be confirmed after further testing.