One month after more than 3,000 patients of a New Jersey hospital were urged to get tested for HIV and other blood-borne diseases, a Brooklyn woman has tested positive for hepatitis B virus (HBV), CNN reports.

The woman, 58, screened positive for the liver virus after having shoulder surgery at HealthPlus Surgery Center in Saddle Brook, New Jersey. In December, all patients who had procedures at the center between January and September 2018 were urged to get blood tests after health officials found serious “issues with sterilization” at the facility.

An investigation by the New Jersey Department of Health found that employees were not following standard sterilization procedures at the hospital and medical instruments were not being cleaned properly in between patients. This is the first confirmed case linked to the facility.

The woman is now part of a federal class-action lawsuit against HealthPlus filed in the Eastern District of New York this week. Her test results came back just days after the lawsuit was filed.