State health officials want to know what caused a salmonella outbreak that sickened more than four dozen people around Indianapolis this summer.

Since late May, 56 cases of salmonella were reported in Marion and surrounding counties. Ten of those victims ended up in the hospital. None became seriously ill. Investigators have theories about where it originated – probably from one source – but they won’t give specifics yet.

"We are looking at Greenwood, Indiana, as a possible source and it is about 56 cases as of today," said Lynae Granzow, Indiana State Department of Health. "We are looking into any possibility that our case investigations provide and that can include restaurants, grocery stores, untreated water sources, any area you may find any food, contaminated livestock, petting zoos, things of that nature."