Incomplete tissue product tracing during an investigation of a tissue-derived tuberculosis outbreak

In the United States, there is currently no system to track donated human tissue products to individual recipients. This posed a challenge during an investigation of a nationwide tuberculosis outbreak that occurred when bone allograft contaminated with Mycobacterium tuberculosis (Lot A) was implanted into 113 patients in 18 US states, including 2 patients at 1 health care facility in Colorado. A third patient at the same facility developed spinal tuberculosis with an isolate genetically identical to the Lot A outbreak strain. However, health care records indicated this patient had received bone allograft from a different donor (Lot B). We investigated the source of this newly identified infection, including the possibilities of Lot B donor infection, product switch or contamination during manufacturing, product switch at the health care facility, person-to-person transmission, and laboratory error. The findings included gaps in tissue traceability at the health care facility, creating the possibility for a product switch at the point of care despite detailed tissue-tracking policies. Nationally, 6 (3.9%) of 155 Lot B units could not be traced to final disposition. This investigation highlights the critical need to improve tissue-tracking systems to ensure unbroken traceability, facilitating investigations of recipient adverse events and enabling timely public health responses to prevent morbidity and mortality.