While the major emphasis of standard precautions has been on hospital settings, the Centers for Disease Control and Prevention drafted infection control guidelines specifically for dentistry in February.

The potential for HCW to develop infectious disease after accidental exposure to patients’ blood or bodily secretions has served as the cornerstone for development of infection control precautions during the past 200 years. In addition, the recognition of multiple risk factors, as well as the development, implementation and updating of infection control guidelines aimed at protecting medical professionals, historically preceded routine prevention recommendations for dental HCW. It also must be noted here that accumulated evidence strongly indicates that microorganisms are transmitted via the same routes, and with the same potential disease outcomes, in both medical and dental care settings.³ Primary goals of current infection control guidelines therefore have been designed and stated to protect all HCW; additional recommendations have been made for selected types of health care settings, such as hospitals, dental care facilities, nursing homes and in-home care settings.

The evolution of infection control has been able to incorporate a wealth of scientific and clinical data into recommendations that were considered reasonable and effective when they initially were made. One of the major early changes in standards and practices employed from the late 1800s through the 1950s involved treating patients with infectious diseases in general hospitals, instead of in separate facilities as had been the case previously. Because of the difficulties sometimes involved in distinguishing infectious conditions from noninfectious conditions—therefore making it difficult to assign the correct patients to free-standing infectious-disease treatment facilities—precautions were designed to provide maximal protection in a variety of health care settings. Even when certain patients were treated in general care facilities, the earlier practice of isolation or quarantine was used with patients who had known infectious diseases being housed in separate hospital areas or rooms. These precautions were aimed at maintaining physical separation of these patients to minimize microbial transmission to both other hospitalized people and the health care personnel who came into contact with the infectious patients. Eventually, even hospitals designed for special types of patients, such as those with active tuberculosis, were closed, as patients were treated successfully in other facilities in the absence of nosocomial infection.⁴

The isolation and characterization of hepatitis B virus, or HBV, along with subsequent documentation of the significant infection risk this virus posed as an accidental bloodborne pathogen for HCW, stimulated a major new infection control emphasis that focused on needle and syringe precautions to prevent accidental sharps injuries.⁵ As a result, recognition of the necessity to target prevention of microbial infection with HBV—and later HIV and hepatitis C virus, or HCV—led to development of a series of updated guidelines for HCW infection control that emphasized bloodborne occupational risks.^1,6–12 As seen in Table 2, other recommendations also were developed, primarily for acute care medical facilities, advocating additional precautions to block direct, indirect contact, droplet, airborne and vector-borne mechanisms of microbial transmission.¹³

Introduction and recommendation of UP replaced the 1983 CDC Guidelines for Isolation Precautions in Hospitals.¹⁵ A key feature for success of this disease prevention proposal was the allowance of increased decision making by hospital personnel at several category levels of infection risk. Even though these recommendations were viewed as an improvement over earlier isolation infection control guidelines published in 1975,¹⁶ an extensive series of category-specific recommendations still required hospitals to decide between using disease-specific isolation precautions as provided in the recommendations or developing unique isolation systems for their individual facilities. A number of important medical categories were used:

– blood and body fluid precautions;

– strict isolation;

– contact isolation;

– respiratory isolation;

– tuberculosis isolation;

– enteric precautions;

– drainage/secretion precautions.

Unfortunately, because many of the HCW occupational blood exposure concerns were based on suspected HIV risks, the impact of UP overshadowed other isolation precautions needed by many clinicians not working in acute care hospital settings. While the adoption and routine use of UP has proven to be very successful in minimizing the potential for transmission of bloodborne pathogens, these practices did not eliminate the need to address the issue of category- or disease-specific isolation precautions for nonbloodborne infections in nonhospital medical facilities.

In 1987, a body substance isolation, or BSI, system was proposed¹⁷ and later refined¹⁸ by Lynch and colleagues. The BSI concept focused on the reduction of transmission of infectious material from any moist body substance. BSI systems were designed to address isolation procedures of all moist, potentially infectious body substances regardless of their presumed infection status. These included blood, feces, urine, sputum, saliva, wound exudates and other body fluids. The distinguishing feature of these recommendations was for HCW to wear gloves when anticipating contact with blood, secretions, mucous membranes, nonintact skin and moist body substances during treatment of all patients. The BSI system protocol advocated additional protection for HCW, including immunization against selected infectious diseases transmitted by airborne or droplets modalities (such as measles, mumps, rubella and varicella) and appropriate barriers (for instance, gowns). For additional information, the reader is referred to an excellent review summarizing both successes and controversial elements of the 1987 BSI system.⁴ Unfortunately, confusion was evident among HCW regarding the difference between UP and BSI.¹⁹ The BSI recommendations also did not cover all necessary precautions to prevent transmission, including droplet transmission of certain bacterial agents among children, and direct or indirect contact cross-infection of important nosocomial pathogens, such as Clostridium difficile and vancomycin-resistant enterococci.⁴

In 1996, in an effort to prevent any potential infectious problems that might arise as a result of the confusion between BSI and UP, the Centers for Disease Control and Prevention, or CDC, developed and published new guidelines for isolation precautions in hospitals termed "standard precautions."⁴ In recognition of the previously noted concerns among some HCW groups, the introduction of standard precautions for use in acute care hospitals incorporated major features of both UP and BSI.²⁰ Since that time, the use of standard precautions has replaced use of both of its individual components. The box summarizes the major principles of and rationale for this approach.

	CONCLUSION

TOP ABSTRACT CONCLUSION REFERENCES

 
Dental care professionals routinely are at risk of cross-infection while providing care to patients. Accumulated findings investigating medical and dental HCW occupation-related infections indicate that repeated exposure to microorganisms in blood and other secretions resulted in a higher incidence of certain infectious diseases than that observed for the general population. This article reviewed the evolution of published infection control recommendations from the CDC, ADA and other health professional organizations that were designed to best protect HCW from the multiple infectious disease challenges they routinely encounter. Initial guidelines released in the 1970s primarily focused on protecting all HCW from bloodborne microbial pathogens, such as HBV. Ongoing investigation and consideration of other nonbloodborne modes of cross-infection subsequently resulted in the development of a series of other BSI precautions, aimed primarily at protecting HCW in acute care facilities, to minimize potential transmission of a variety of bacterial, viral and mycotic organisms via respiratory, contact or other exposures with infectious body fluids. The success of BSI in medical care settings and the documented effectiveness of UP providing effective infection control for HCW against blood-borne pathogen transmission has led to evolution of the current recommendations that use the best features of UP and BSI. The updated CDC infection control recommendations for dentistry undoubtedly will be expanded to incorporate prevention protocols and practices aimed at further protecting dental care providers from the variety of well-characterized and emerging nonblood-borne, occupational microbial agents. There is little doubt that the dental profession will respond in the same positive manner to the new standard infection control guidelines as it did to earlier UP recommendations, thereby continuing to provide protection for both those who provide care and their patients.