4:47 Musculoskeletal allograft contamination and recipient exposure to pathogens

Abstract

Purpose of study: The purpose of this study was to quantify the risk of musculoskeletal allograft contamination and recipient exposure to bacteria, human immunodeficiency virus (HIV), hepatitis B virus (HBV) or hepatitis C virus (HCV). Also, the sources of risk, current methods of screening and testing donors to prevent allograft contamination and initiatives to provide improved assurance of patient safety are reviewed.Methods used: The risks of allograft contamination with HIV, HBV, HCV or bacteria were estimated from data concerning the prevalence rates of disease among potential donors, durations of the infectious “window” periods before disease can be detected, the sensitivity of donor testing and effectiveness of commonly used methods of tissue processing in eliminating pathogens. Calculations of the total numbers of contaminated allografts distributed in the United States annually were based on the estimated rates of allograft contamination and data concerning the numbers of allografts used in the United States.of findings: The reported sensitivities of testing for HIV (99.9%) and HBV (100%) are very high. Consequently, the main sources of contamination risk for these two pathogens are the durations of the infectious “window” periods of approximately 22 days for HIV and 59 days for HBV. The rates of allograft contamination among donors who have passed all screening, testing and conventional methods of processing are estimated to be 1 in 49,000 for HIV and 1 in 6,300 for HBV. HCV poses a greater risk, because the infectious “window” period duration is longer (82 days) and the sensitivity of testing is lower (97.2%). The estimated rate of contamination with HCV is 1 in 2,500 donors who have passed all screening, testing and conventional methods of processing. Bacterial contamination rates are more difficult to quantify but are likely at least 3%. Given that 750,000 or more musculoskeletal allografts are distributed annually in the United States, an average of at least several hundred recipients are likely exposed to bacteria, HIV, HBV or HCV from contaminated allografts.Relationship between findings and existing knowledge: Several case reports document that bacterial and viral diseases can be transmitted to recipients through transplantation of contaminated musculoskeletal allografts. The findings from this study are particularly useful in defining the extent of this public health problem because, as reported by investigators at the Centers for Disease Control (CDC), the numbers of persons who develop disease from contaminated allografts remain unknown. The reasons for this include the absence of a requirement for reporting of such infections, the lack of systematic testing of allograft recipients before and after surgery and the difficulty in determining with certainty the cause of postoperative infections.Overall significance of findings: The greatest risks in terms of total numbers of contaminated allografts are the result of bacteria and HCV. Unfortunately, this leads to recipient exposure to disease, because aseptic methods of processing donor musculoskeletal tissue, as far as we are aware, have not been shown to actually sterilize the tissue. For this reason, our findings support statements from both the CDC and the US Food and Drug Administration in calling for development of safe and effective sterilization methods for musculoskeletal tissue.Disclosures: No disclosures.Conflict of interest: Robert Kennedy, consultant to Regeneration Technologies Inc.