Testing the tissue and the environment

Abstract

Testing for infectious microbes such as bacteria and fungi (yeast and molds) plays an important role in ensuring the safety of tissue allograft transplantation. Testing is routinely performed on the donated tissue prior to processing, on the allograft after processing as final testing, and to prevent contamination and cross contamination during processing. In the past, bacterial and fungal infections transmitted from contaminated tissue allografts were considered rare anomalies, whereas donor-derived HIV, hepatitis and other viral and prion infections were considered more important threats to patients. Indeed, tissue transplantation has resulted in donor-to-recipient transmission of HIV, hepatitis, human T-cell lymphotropic virus, rabies, Herpes simplex, Epstein-Barr virus, cytomegalovirus, and transmissible spongiform encephalopathies [1, 2]. Tissue banks and standard-setting bodies have emphasized the importance of preventing these viral and prion diseases, even though the risk is low. In most countries, blood testing of tissue donors for infectious diseases parallels that for blood donors and includes antibody testing for viruses and syphilis and when needed for selected parasites. In some countries, direct blood testing for HCV and HIV nucleic acid has been implemented for tissue donors as well as with blood donors. In contrast with blood component transfusion, testing for tissue allografts also relies on the routine use of microbiologic testing for bacteria and fungi to ensure patient safety, as explained in this chapter.