CHICAGO (AP) — The medical director of three Illinois clinics that used a possibly tainted steroid medication says four patients received follow-up tests for meningitis and all got reassuring results.

Dr. Randolph Chang of APAC Centers for Pain Management told The Associated Press on Monday the patients had spinal taps because they experienced mild symptoms. He says there are still no confirmed cases of meningitis among the clinics' patients.

Chang says the APAC clinics notified about 150 patients who received back injections of a steroid made by a pharmacy in Massachusetts. Health inspectors found fungus in at least one sealed vial of the steroid at the Massachusetts company's facility last week.