The probe has grown since federal authorities expanded their inquiry into a Massachusetts pharmacy linked to tainted steroid shots.
Two Pennsylvania health clinics received that medication, which has been linked to fungal meningitis. One state resident has been hospitalized with the illness.
Now, the Food and Drug Administration is recommending health officials monitor patients who received any injectable product from the pharmacy after May 21.
The state Health Department on Friday said more than 150 medical facilities in Pennsylvania are in the process of notifying affected patients.
The meningitis outbreak has killed 21 people and sickened more than 270 across the U.S.