Infections in transplant recipients

Introduction Infections are the most common complication of organ and tissue transplantation. While the focus of antimicrobial prevention after transplantation has been on reducing the incidence of opportunistic infections, transplant recipients remain at risk of virtually any bacterial, fungal, viral, and parasitic pathogen. These pathogens cause clinical disease with increased severity 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) increase the risk of infectious complications. Generally, the overall infection risk after transplantation is determined by (1) epidemiologic exposures of the donor and the recipient and (2) the overall net state of immunosuppression. Epidemiologic exposures 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 (donor-derived infections); and (3) the environment (hospital and community). Table 89.1 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 89.2 lists the recommended screening tests in the evaluation of potential recipients (and their donors) prior to transplantation. Some candidates will be found to have active infection; these infections do not generally preclude transplantation, but they should be adequately controlled and treated prior to and after the transplant procedure. THE TRANSPLANT DONOR The epidemiologic exposures of transplant donors should be determined so that the potential for donor-derived infections is reduced.