Prophylaxis against fungal infections in transplant recipients: possible approaches

Although the morbidity and mortality associated with invasive fungal infections in transplant recipients is high, the optimal approach to antifungal prophylaxis is controversial. Most fungal infections occur shortly after the trans- plantation during maximum immunosuppression and are caused by Candida or Aspergillus spp. Nonspecific strategies for prevention do not differ from those used in other patients at risk. They consist mainly of a reduction in risk factors, such as removal of plants from around the patient, separation of the patient from the vicinity of construction sites or improvement in hospital care by isolation and careful nursing of the patient, with strict hygiene. A more controversial issue is primary antifungal chemoprophylaxis, since there are few well designed trials of this intervention, and most of the patients studied have had haematological diseases. Orally administered antifungal drugs that are not absorbed through the gastrointestinal tract have not shown any evidence of a prophylactic effect to date. Controlled trials of systemically administered or orally absorbed drugs in specific transplant recipients have, however, proved effective. In allogeneic and autologous bone marrow transplants, fluconazole 400 mg/day was effective when administered from the conditioning treatment period through the neutropenic period. In liver transplant recipients, either fluconazole 400 mg/day for 10 weeks or liposomal amphotericin B 1 mg/kg/day for 5 days significantly reduced the incidence of invasive fungal infections. However, one must be aware of the risk of fluconazole-resistant fungi and the possibility of selection. In patients with a history of previous fungal infection, secondary prophylaxis may be of value, although data are limited. For recipients of transplants other than bone marrow or liver, there are insufficient data to recommend general prophylaxis.