A federal judge has refused to expand a lawsuit beyond the seven people who are suing a South Dakota urology clinic and its owners.

The plaintiffs sought to make it a class action suit representing more than 6,000 patients.

The lawsuit against Siouxland Urology Center in Dakota Dunes and doctors alleges that the former patients could have been exposed to blood-borne infections because medical equipment that was intended for single-patient use was reused at the clinic.

U.S. District Judge Karen Schreier ruled that the complaint did not meet all the requirements for class action status.

The plaintiffs, identified as Iowa residents, seek more than $5 million on allegations that include negligence, medical malpractice, and emotional distress.