County and state health officials continue investigating a salmonella outbreak at a South San Francisco restaurant in July that may be linked to raw almonds. One worker and 21 diners were left sick after eating La Tapatia Restaurant, reports the San Mateo County Daily Journal.

State investigators discovered La Tapatia bought raw almonds in bulk from a large food retailer and repackaged them for resale. However, all of the almonds confiscated from the restaurant all tested negative for that strain.

Currently, officials are comparing the outbreak to a similar incident in Berkeley during the same time period.

No illnesses have been reported since the initial batch.