Collectively, infections are the single most common complication of organ and tissue transplantation. Virtually any bacterial, fungal, viral, and parasitic pathogen can cause clinical disease in a transplant recipient. Several factors inherent to the transplant recipient or related to the donor, the environment, and the circumstances surrounding the transplant procedure (such as surgical techniques and immunosuppressive drugs) remarkably increase the risk of infectious complications. Generally, the overall infection risk is determined by (1) epidemiologic exposures and (2) the net state of immunosuppression.
RISK FACTORS OF INFECTION AFTER TRANSPLANTATION
The major sources of pathogens are (1) the transplant recipient who may harbor latent, active, or subclinical infection prior to transplantation; (2) the donor who may harbor latent, active, or subclinical infection that could be transmitted through the allograft; and (3) the environment surrounding the immunocompromised transplant patient. Table 87.1 lists some risk factors for acquiring infection after solid organ transplantation.
THE TRANSPLANT RECIPIENT
The epidemiologic exposures of potential transplant recipients should be assessed to determine the risk of infection and guide preventive measures. Table 87.2 lists the recommended screening tests in the evaluation of potential recipients (and their donors) prior to transplantation; these include screening for herpes simplex virus (HSV) 1 and 2, varicellazoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), human T-cell lymphotrophic virus (HTLV) I/II, hepatitis viruses, Mycobacterium tuberculosis, Toxoplasma gondii, and Treponema pallidum.