Linking Antimicrobial Use to Nosocomial Infections: The Role of a Combined Laboratory-Epidemiology Approach

Nosocomial infections are an important cause of increased morbidity, mortality, and health care costs worldwide. Conservative estimates for 1992 were that nosocomial infections increased the annual cost of health care in the United States by more than $4.5 billion [1] and contributed to almost 80 000 deaths. Nosocomial infections may be one of the five leading causes of death in the United States, and we must make their prevention a public health priority [2, 3].

Nosocomial infections reflect the worldwide dynamics of health care delivery. In the developing world, complex medical technologies, including invasive devices and procedures, may be introduced without the appropriate infection-control infrastructure in place. Thus, as the use of these technologies increases, so do the risks for nosocomial infection, antimicrobial use, and emergence of antimicrobial-resistant pathogens. The concurrent downsizing and merging of health care systems in the developed world ensure that nosocomial infections will remain important in these settings for years to come. Recent studies suggesting a link between decreased nurse staffing levels and increased risk for infection [4, 5] are one example of how changes in health care delivery can affect rates of nosocomial infection; in addition, infection rates will probably increase as an increased proportion of U.S. hospital beds are occupied by severely ill patients in intensive care units who are exposed to numerous devices and antimicrobials.

In this issue, Villers and colleagues [6] illustrate the complex relation between the practice of medicine (specifically, antimicrobial use) and the risk for nosocomial infection. They also show the value of combining laboratory and epidemiologic investigations. First, they used molecular typing to show that …