Complex invasive procedures, such as tissue or organ transplantation, can also lead to nosocomial infection. The immunosuppressive drugs used to prevent the rejection of the foreign tissue or organ have the undesirable side effect of weakening the body's immune system. Often, these infections do not involve hospital microbes but pathogens from the donor tissue or pathogens that are already present in the recipient. Extensive testing of foreign tissue prior to transplantation guards against transmission of most such microbes. Latent agents, however, like the "slow" virus that causes Creutzfeld-Jacob disease, are extremely difficult to detect and may be inadvertently transferred to the transplant recipient in the seemingly normal tissue of the donor. Cases of HIV infection, hepatitis C, and CMV infection resulting from organ transplantation have all been documented, as have cases of Creutzfeld-Jacob, a degenerative brain disease, in recipients of transplanted corneas and human growth hormone (Lorber, 1988; Pereira et al., 1991).
Changes in health care delivery over the past 20 years undoubtedly have had an impact on nosocomial infection rates. Rising health care costs play a key role. One cost-conscious health care strategy that appears to be contributing to the rise in cases of nosocomial infection is so-called industrial management in hospitals. Industrial management is intended both to maximize the ratio of patients to nurses and to maintain pools of health care workers—particularly nurses—who can rotate frequently between two or more units of an institution. From the hospital's perspective, maximizing the ratio of patients to nurses is desirable because it decreases health care costs. At the same time, the practice can increase disease transmission by reducing the time available for proper sanitation and increasing the number of infected patients to whom a nurse is exposed.
Exacerbating the potential disease-producing quality of these problems is the increasing bidirectional transfer of patients between acute care and chronic care hospitals. The mixing of patients from acute care facilities (who tend to be severely ill) with residents of chronic care hospitals (who tend to have decreased immune function owing to aging or chronic illness, or both) is potentially risky. Compared with hospital-based programs, infection control programs in many long-term care facilities are rudimentary, at best. Unlike hospital-based programs, there are no standardized criteria for defining nosocomial infections in long-term care facilities; in addition, adequate studies designed to assess the efficacy of their surveillance and control measures have not been conducted. This state of affairs contrasts sharply with such efforts in acute care hospitals, which have received for more attention and federal funding.