Over 100 people in the Chicago area became sick after receiving syringes of Heparin contaminated with bacteria that infects bloodstreams.
The affected are all from Rush University Medical Center.
According to the hospital, 114 outpatients receiving home infusion therapy, all got bloodstream infections.
Twenty of those people became so sick they had to be treated and hospitalized.
Rush says these infections were traced to a batch of pre-filled heparin syringes manufactured by Sierra Pre-Filled Incorporated.
However, hospital officials say the problem has been contained and isolated.
All the syringes were apparently from the same manufacturer and the same lot number.
Heparin is a blood thinner that prevents the formation of blood clots.