The Allegheny County Health Department today reported that a growing number of county residents are being diagnosed with a diarrheal illness known as shigellosis.

A news release said 60 shigellosis cases have been reported countywide since October — 34 so far this year — compared to just 12 cases of the disease in all of 2008 and five in 2007. Nearly half of the 60 cases were children 5 or younger and about one-third of the cases had contact with a family member or someone in a school or day care center who had diarrheal illness.