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This chapter considers aspects of infection unique to patients receiving transplanted tissue. The evaluation of infections in transplant recipients involves consideration of both the donor and the recipient of the transplanted cells or organ. Two central issues are of paramount importance: (1) infectious agents (particularly viruses, but also bacteria, fungi, and parasites) can be introduced into the recipient by the donor; and (2) treatment of the recipient with medicine to prevent rejection can suppress normal immune responses, greatly increasing susceptibility to infection. Thus, what might have been a latent or asymptomatic infection in an immunocompetent donor or in the recipient prior to therapy can become a life-threatening problem when the recipient becomes immunosuppressed. The pretransplantation evaluation of each patient should be guided by an analysis of both (1) what infections the recipient is currently harboring, since organisms that exist in a state of latency or dormancy before the procedure may cause fatal disease when the patient receives immunosuppressive treatment; and (2) what organisms are likely to be transmitted by the donor, particularly those to which the recipient may be naïve.
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PRETRANSPLANTATION EVALUATION
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A variety of organisms have been transmitted by organ transplantation. Transmission of infections that may have been latent or not clinically apparent in the donor has resulted in the development of specific donor-screening protocols. Results from routine blood bank studies, including those for antibodies to Treponema pallidum (syphilis), Trypanosoma cruzi, hepatitis B and C viruses, HIV-1 and -2, human T-lymphotropic virus types 1 and 2 (HTLV-1 and -2), and West Nile virus (WNV), should be documented. Serologic studies should be ordered to identify latent infection with viruses such as herpes simplex virus types 1 and 2 (HSV-1, HSV-2), varicella-zoster virus (VZV), cytomegalovirus (CMV), Epstein-Barr virus (EBV), Kaposi’s sarcoma–associated herpesvirus (KSHV); acute infection with hepatitis A virus; and infection with the common parasite Toxoplasma gondii. Donors should be screened, when relevant, for viruses such as rabies virus and lymphocytic choriomeningitis virus as well as for parasites such as Strongyloides stercoralis and Schistosoma species. Clinicians caring for prospective organ donors should examine chest radiographs for evidence of granulomatous disease (e.g., caused by mycobacteria or fungi) and should perform skin testing or obtain blood for immune cell–based assays that detect active or latent Mycobacterium tuberculosis infection. An investigation of the donor’s dietary habits (e.g., consumption of raw meat or fish or of unpasteurized dairy products), occupations or avocations (e.g., gardening or spelunking), and travel history (e.g., travel to areas with endemic fungi) also is indicated and may mandate additional testing. Creutzfeldt-Jakob disease has been transmitted through corneal transplants. Whether it can be transmitted by transfused blood is not known. Variant Creutzfeldt-Jakob disease can be transmitted with transfused non-leukodepleted blood, posing a theoretical risk to transplant recipients.
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It is expected that the recipient will have been even more comprehensively assessed ...