The Centers for Disease Control and Prevention (CDC) is investigating an outbreak of tuberculosis (TB) linked to a medical putty that helps heal bones after different kinds of surgery.

The putty is known as FiberCel Fiber Viable Bone Matrix, and it’s made by Aziyo Biologics. It’s made from human tissue.

According to Aziyo, 154 containers of FiberCel were made from the human tissues of some who had tuberculosis.

The contaminated putty was shipped to 37 facilities in 20 states. 136 of the containers were used on 113 patients.

Eight of the 113 died after surgery. However, those deaths are still under investigation, and it is unclear if the putty played a role.

Aziyo recalled FiberCel in early June.

“Patient health and safety are our highest priority. Accordingly, we have implemented this voluntary recall and instructed hospitals that received FiberCel product from this specific donor lot to immediately quarantine and return any remaining product to us,” said Ron Lloyd, Aziyo’s president and chief executive officer. “We are committed to a thorough, timely and transparent investigation into the root cause of these infections.”

Last week, a patient infected by TB filed a lawsuit against the company.