Illnesses in the ongoing E. coli O157:H7 outbreak in central Missouri rose to 15 on Friday, while information on the individual infections suggests they may come from multiple sources.

Of the 15 cases, seven individuals have reported that they consumed raw milk products from a single dairy in Howard County. As a result, the dairy has been under investigation and has halted sales of its raw milk products.

The E. coli infections in six of those seven raw milk drinkers have shown to match by their identifiable genetic pattern known as a pulsed-field gel electrophoresis (PFGE). The infection of the seventh raw milk drinker — the newest addition to the total number ill — has a different PFGE pattern, though one that is very similar to the other six, according to epidemiologist Sarah Rainey at Missouri’s Columbia-Boone County Health Department.

Of the other eight illnesses — the ones who did not report consuming raw milk products — only one individual has a PFGE pattern matching the raw milk drinkers. The other seven infections vary genetically or have not returned a PFGE reading.

According to Rainey, this significant disparity suggests that the raw milk drinkers may have been contaminated by the dairy — their one common source — while the other eight infections are likely not related to the raw milk dairy and come from another source.

Missouri Department of Health and Social Services spokeswoman Gena Terlizzi confirmed these PFGE statistics to Food Safety News, adding that the PFGE pattern of the raw milk drinkers’ infections is “a somewhat common PFGE.”

Terlizzi said the state health department continues to investigate the outbreak’s possible source or sources and has not come to any conclusions.

The newest case in the outbreak is a child under 18 from Boone County who was hospitalized from the infection but has since been released. A 2-year-old from Boone County has been hospitalized for more than two weeks after developing symptoms of hemolytic uremic syndrome (HUS), a kidney disease associated with severe E. coli infections.

The 15 illnesses are spread across Boone, Camden, Clarke, Cooper, Howard and Jackson counties.