This article describes ethical dilemmas faced routinely by infection control personnel and outlines the basic principles of ethics as applied to the practice of infection control and hospital epidemiology.

Organisms living on our external and internal body surfaces are the first contact for many potentially pathogenic invaders. Factors that alter this microenvironment include antibiotics, the host immunity, and the various diseases of man and their treatment. Predicting when colonization leads to infection remains an important challenge for every clinician. The maintenance and breakdown of colonization resistance by changes in the native microflora and the body's natural mucosal coating by various extrinsic and intrinsic factors is reviewed in this article. Quantitative culture methods developed to improve the predictive value of a given sampling technique (most notably with bronchoscopy) is presented. Besides improving diagnostic capabilities, quantitative cultures can be used successfully as an epidemiologic tool for some outbreak investigations.

There is intense antimicrobial use in long-term–care facilities (LTCF), and studies repeatedly document that much of this use is inappropriate. The current crisis in antimicrobial resistance, which encompasses the LTCF, heightens concerns of antimicrobial use. Attempts to improve antimicrobial use in the LTCF are complicated by characteristics of the patient population, limited availability of diagnostic tests, and virtual absence of relevant clinical trials. This article recommends approaches to management of common LTCF infections and proposes minimal standards for an antimicrobial review program. In developing these recommendations, the article acknowledges the unique aspects of provision of care in the LTCF.

During the last quarter century, numerous reports have indicated that antimicrobial resistance commonly is encountered in long-term–care facilities (LTCFs). Gramnegative uropathogens resistant to penicillin, cephalosporin, aminoglycoside, or fluoroquinolone antibiotics and methicillin-resistant Staphylococcus aureus have received the greatest attention, but other reports have described the occurrence of multiply-resistant strains of Haemophilus influenzae and vancomycin-resistant enterococci (VRE) in this setting. Antimicrobial-resistant bacteria may enter LTCFs with colonized patients transferred from the hospital, or they may arise in the facility as a result of mutation or gene transfer. Once present, resistant strains tend to persist and become endemic. Rapid dissemination also has been documented in some facilities. Person-to-person transmission via the hands of healthcare workers appears to be the most important means of spread. The LTCF patients most commonly affected are those with serious underlying disease, poor functional status, wounds such as pressure sores, invasive devices such as urinary catheters, and prior antimicrobial therapy. The presence of antimicrobial-resistant pathogens in LTCFs has serious consequences not only for residents but also for LTCFs and hospitals. Experience with control strategies for antimicrobial-resistant pathogens in LTCFs is limited; however, strategies used in hospitals often are inapplicable. Six recommendations for controlling antimicrobial resistance in LTCFs are offered, and four priorities for future research are identified.