The Rhode Island Department of Health has increased to 23 the number of possible salmonella cases in people who consumed zeppoles made by DeFuscos’s Bakery in Johnston.

And the department now says the source of the salmonella contamination may not be just the cream used in the filling of the zeppole shells, but the shells themselves.

Andrea Bagnall-Degos, a Health Department spokeswoman, said Sunday that lab tests have confirmed 13 cases of salmonella so far among the suspected 23 reported illnesses. Thirteen people have been hospitalized; 10 remained in the hospital as of midday Sunday, she said.

The Providence Journal reports DeFusco’s Bakery voluntarily closed after health inspectors found that pastry cream was stored at unsafe temperature and in unsanitary conditions.

Bagnall-Degos said the health department has now determined that the bakery stored zeppole shells in used egg crates, possibly exposing the shells to raw egg residue.