Infection in organ transplantation: risk factors and evolving patterns of infection

The nature of infections after solid-organ transplantation has changed with increasingly potent immunosuppressive regimens, routine use of antimicrobial prophylaxis, and improved microbiologic diagnostic tools. New pathogens have been identified in this population including many with significant antimicrobial resistance. Intensification of immunosuppressive regimens, including the use of T- and B-lymphocyte depleting agents, presents an increased risk for infection and requires linkage to microbiologic monitoring and prophylaxis against opportunistic infections. The effect of these regimens is reflected in the increased recognition of viral and fungal infections beyond 1 year after transplantation. Donor-derived infections represent a challenge to organ transplantation in terms of microbiologic screening of donors and the need for communication among clinical centers, organ procurement organizations, and public health authorities. New approaches to microbiologic assessment of organ donors and recipients are needed. In the future, improved assays for microbiologic and immunologic monitoring will allow individualization of prophylactic strategies to reduce the risk of infection in this highly susceptible population.