[The most common infections in the transplanted patient].
Organ transplantation has become one of the most important areas of medical research and, at present, is still the only therapeutical tool for several diseases. However, there are a number of factors related to transplantation, like immunosuppression and prolonged neutropenia that affect the incidence of infection. These infections are somehow peculiar to transplant recipients. In fact, there are infectious diseases that only occur in immunodepression situations and, moreover, clinical expression of these infectious diseases can be quite different from that in immunocompetent patients. Besides these aspects, some infections, due to the high prevalence described, must be considered for prevention strategies because they continue to be a principal cause of morbidity and mortality, either due to direct effects or to their implication in the pathogenesis of rejection. These strategies commence before transplantation by active immunization through vaccine administration to the patient and to people in the milieu and continue after transplantation with prophylaxis or pre-emptive therapy. The importance of infectious diseases in the evolution and prognosis of transplant recipients gives a special meaning to the understanding of associated infections, their clinical expression and ways of prevention and treatment.