Clark County health officials lifted the closure order for a restaurant in Vancouver, Wash. that was linked to at least 23 confirmed salmonella cases and as many as 54 more.

On the Border Mexican Grill was closed on Oct. 9 to prevent salmonella from spreading after customers reported getting sick.

Dr. Alan Melnick, Clark County Health Officer, said restaurant employees have been tested for salmonella and those who did not have the infection were cleared to return to work.

It’s unclear what caused the outbreak.