Infectious diseases in the liver transplant recipient.

Despite a declining incidence, infections remain a significant complication in liver transplant recipients. The spectrum of infections in transplant recipients, however, appears to be evolving. Infections caused by gram-positive bacteria (e.g., enterococci and staphylococci) have now surpassed in frequency those caused by gram-negative bacteria. There has been a decline in the incidence of Pneumocystis carinii and more recently cytomegalovirus infection in transplant recipients, largely as a result of effective prophylaxis. Opportunistic fungal infections (e.g., aspergillosis) remain problematic. New or previously unrecognized pathogens (e.g., human herpesvirus-6) may also be a significant cause of morbidity. Evaluation of infections in transplant recipients therefore requires understanding of not only classic opportunistic infections typically encountered in these patients, but also emerging trends in epidemiology, prophylaxis, and management.