It can be said that the greatest pitfall for the infection control practitioner lies in the realm of problem solving'; however, responding to potential problems is intrinsic to the role of the infection control practitioner. Potential problems are presented to the infection control practitioner not only by his or her employees and supervisors, but also from medical and other hospital staff. Not only do potential problems come from a variety of sources, but their significance may vary from unimportant to critical. In some cases, problems are minor and require little action. In other cases, problems represent critical emergencies and necessitate immediate and aggressive responses. Whether the infection control practitioner works in a small patient care unit or a large university hospital, correct assessment and response to a potential problem is a crucial aspect of effective management.

In most cases when a problem is presented, there is agreement by both presenter and infection control practitioner that a problem exists. For example, a patient may have methicillin-resistant Staphylococcus aureus (MRSA) infection. In other cases, while there is agreement that a problem exists, there may not be agreement on the importance of the problem. For example, what is seen by the infection control practitioner as a serious problem may be seen by a physician as a minor problem.

Healthcare personnel injured by needles or other sharps contaminated with blood from infected patients are at risk for infection with human immunodeficiency virus (HIV), hepatitis B virus (HBV), and other bloodborne pathogens.’ When such injuries also result in blood contamination of a patient's wound, mucous membrane, or skin lesion, transmission of infection in the opposite direction, from provider to patient, may occur.

Although HBV transmission from HBeAg- positive providers to patients during invasive procedures where the opportunity for injury and contamination coexists was documented as early as 1974, the hazard was not deemed large enough to warrant widespread changes in infection control practices or mandatory testing. Recent reports suggesting that HIV infection in three patients of a dentist with acquired immunodeficiency syndrome (AIDS) were acquired in the dental office have had a much more dramatic impact.

Birnbaum and others' recently published an article about adoption of guidelines for Universal Precautions (UP) and Body Substance Isolation (BSI) in Canadian acute-care hospitals. The authors pointed out that terminology was used inconsistently among the Canadian hospitals and that there was considerable confusion about the meaning of different terms.

As two of the developers of the BSI system, we have been impressed that the philosophical differences among the isolation systems are also misinterpreted by many. The primary purpose of an isolation system, and why and when and it is implemented, form the bases for the philosophical differences among the different systems. Failing to understand the fundamental differences leads practitioners incorrectly to apply the methods of the system in use at their facilities and also leads to inconsistency in practice among healthcare workers.

The primary purpose of BSI is to reduce risks to patients of cross-transmission of microorganisms via hands of healthcare workers. A secondary benefit of BSI is to protect the healthcare worker from microorganisms harbored by patients. The system is based on three fundamental premises.