Diagnosis and treatment of infection in cardiac transplant patients.

Despite major advances in the management of rejection and the development of newer and more potent antimicrobials, infection still constitutes a major problem in transplant patients and other immunosuppressed hosts. Infectious complications in transplant patients clearly occur in two phases. The first phase includes the first 30 to 60 days after transplantation. During this period, nosocomial bacterial infections are most commonly encountered. Pulmonary, renal, and wound infections have all been encountered, and prophylactic antibiotics appear to decrease their frequency. Opportunistic infections usually do not occur during this period unless the patient undergoes treatment for acute rejection. The second phase of infectious complications usually follows the first month after transplantation. In this period, the level of immunosuppression is high, and opportunistic infections are common. Opportunistic pulmonary infections caused by P. carinii, L. pneumophila, cytomegalovirus, Aspergillus, and Nocardia spp. all are potentially life-threatening complications to the transplant patient. Aggressive diagnostic tests such as bronchoscopy, percutaneous needle biopsy, or open lung biopsy are frequently needed to make a diagnosis. Empiric broad-spectrum antimicrobial therapy is indicated in the ill patient; however, more specific therapy should be instituted once the diagnosis is confirmed.