The number of confirmed salmonella cases from an outbreak traced to the Sheetz convenience store chain hasn’t changed in the last month or so, meaning the outbreak is at an end.

The Beaver County Times reports that although there were 330 confirmed cases in Pennsylvania and at least 80 in neighboring states, Pennsylvania Department of Health spokesman Richard McGarvey said Friday there were probably many more cases related to the outbreak that went unreported.

That, McGarvey said, is because some people who may have been sickened in the outbreak did not go to the doctor, so there was no official diagnosis made. McGarvey said there’s no way of knowing how many unreported cases there might have been.

The outbreak is thought to have been caused by contaminated Roma tomatoes served at nearly 16 Sheetz stores in western Pennsylvania and along the Pennsylvania Turnpike.

The FDA is still investigating whether the tomatoes were contaminated at the supplier, Coronet Foods of Wheeling, West Virginia.