1. A source of microorganisms, a mode of transmission, and a susceptible host are needed for infection to occur. Transplant recipients are susceptible because normal defense mechanisms are undermined by cytotoxic agents and steroids to prevent rejection of the allograft. 2. The specific type of organ transplant affects the site and type of infection. The stress of surgery and the duration of the operative procedure are important risk factors. The more the patient is subjected to invasive procedures, the greater the risk for infection. 3. The responsibility of maintaining sterility for the transplant patient falls on all personnel involved from procurement to implantation. The OR nurse and others involved in transplantation must be aware at all times of the potential introduction of contaminants to the transplant patient.