Isolation of Patients With Communicable Diseases



Isolation of Patients With Communicable Diseases


Jason E. Bowling

Jose Cadena

Jan Evans Patterson



Despite advances in the control of infectious diseases in the last century, there is more interest than ever in the use of isolation precautions to control known and emerging diseases such as multidrug-resistant bacteria, multidrugresistant tuberculosis (MDR-TB), pandemic influenza, and Clostridium difficile infection. These precautions are particularly important in the institutional setting due to the proximity and potential common exposures of patients who have communicable diseases with other patients. The terminology for isolation precautions has changed and developed over the years. Although the universal implementation of Standard Precautions simplified isolation policies to some degree, the terms used for isolation precautions varied among institutions, and some confusion ensued (1,2). In addition, some of the situations outlined above may call for additional measures that are not in “Universal Precautions,” as originally defined. The revision of the guidelines for isolation published in 1996 by the Centers for Disease Control and Prevention (CDC) approached isolation as transmission-based and clarified some confusing issues (3). Based on the positive results, this approach was reaffirmed in the most recent revision of the guidelines (4). Still, the infection preventionist (IP) is frequently called regarding the appropriate use of isolation precautions.


HISTORICAL PERSPECTIVE

The concept of isolating persons with communicable diseases was in practice even in ancient times according to biblical accounts of leper colonies, although the leprosy of biblical times may have been other skin diseases (5). In modern times, hospital construction before 1850 featured crowded open wards (6). As a consequence, cross-infection was common, and mortality rates were high in urban hospitals (7). Florence Nightingale’s observations from the Crimean War (8) led her to advocate small pavilion-type wards joined by open-air corridors. Nightingale emphasized the importance of asepsis and a clean environment. Her teachings were called “fever nursing” and varied from popular concepts of disease at the time, because fever nursing implicated transmission by contact with body substances rather than the environment (9).

The germ theory of infection was accepted in US hospitals in the late 1800s, after the influence of Lister and Pasteur, and conditions began to improve as overcrowding decreased and antisepsis increased (7). Communicable disease hospitals were using individual and group isolation as early as 1889 (10). By the turn of the century, general hospitals were beginning to isolate patients with communicable diseases in an individual room with the use of separate utensils and disinfectants (9,11). Grancher in Paris promoted the theory of communicability by contact rather than airborne spread for most diseases and allowed patients with communicable diseases to be housed in general wards but with separation by wire screens (9). These screens separated the patient from other patients and served as a reminder for staff members to gown and wash their hands. Thus, began the trend in the United States from the isolation hospital to care of communicable diseases in a general hospital setting.

In the early 20th century, Charles V. Chapin of Providence City Hospital used individual isolation cubicles for patients with communicable diseases and documented that fumigation had no effect on secondary cases (12). His work was very important in emphasizing the roles of persons rather than things as spreaders of disease and helped to end the miasmatic theory of transmission (13). Richardson, the physician superintendent of Providence City Hospital, used the barrier method and the cubicle method for isolation of patients, allowing some patients with communicable diseases to be housed in the same room as other patients (9). A card outlining the barrier technique needed was placed on the patient’s bed.

The emergence of Staphylococcus aureus as a hospital pathogen in the 1950s and 1960s prompted the development of infection-control programs in US hospitals. In 1968, the first edition of the American Hospital Association’s manual (13) presented a simple barrier precautions scheme for patients with communicable diseases, listing the need for gloves, gowns, masks, and visitor screening.


EARLY RECOMMENDATIONS FROM CENTERS FOR DISEASE CONTROL AND PREVENTION

While conducting healthcare-associated outbreak investigations in the 1960s, the CDC recognized that standardized
policies for isolating hospitalized patients with communicable diseases were lacking (14). A group of experts convened in 1967 to develop the first CDC isolation recommendations, and first published five categories of isolation in 1970 (15). Even in this initial manual, the philosophy behind the more recently developed Universal Precautions was expressed. By 1976, a survey showed that 93% of hospitals in the United States were using the category-specific approach to isolation (16).

Substantial changes were made in the 1983 CDC recommendations (17). The updated category-specific guidelines for isolation published in 1983 (17) included seven categories of isolation: strict isolation, respiratory isolation, enteric precautions, contact isolation, tuberculosis (acid-fast bacillus [AFB]) isolation, drainage/secretion precautions, and blood and body fluid precautions. These isolation categories grouped diseases that require the same isolation precautions. After the more recent transmissionbased guidelines from CDC, these categories are now of historical interest, but the terms are still commonly used and confused by some healthcare workers. IPs may be called on to clarify and compare these previous categories with the newer guidelines.

In addition, this 1983 guideline introduced disease-specific isolation as an alternative to category-specific isolation. Disease-specific isolation was offered as an alternative for hospitals wanting a more economic system that directed precautions at preventing transmission of a specific disease while avoiding unnecessary isolation precautions for some diseases. The guidelines stated that hospitals could choose the category-specific or the disease-specific system or design their own systems.


CATEGORY-SPECIFIC ISOLATION


Strict Isolation

Strict isolation was used to prevent transmission of diseases spread by both air and contact. Specifications for strict isolation include a private room with the door closed; masks, gowns, and gloves were indicated for all persons entering the room. This category has now been replaced with the use of Standard Precautions (for all patients) or Contact Precautions combined with Airborne Precautions in the new guidelines.


Contact Isolation

Contact isolation was a category designed to prevent the transmission of epidemiologically important microorganisms causing infection or colonization or highly transmissible microorganisms that do not warrant strict isolation. Conditions in this category are spread by direct or close contact. This category has been replaced by Contact Precautions in the new transmission-based guidelines.


Respiratory Isolation

Respiratory isolation was used to prevent droplet nuclei transmission, that is, transmission of diseases over long distances through the air. In the newer guidelines, this category has been replaced by Airborne Precautions.


Tuberculosis Isolation (Acid-Fast Bacillus Isolation)

Tuberculosis isolation was referred to as AFB isolation on the standard instruction card to protect patient confidentiality (17). Airborne Precautions have replaced this category in the new guideline. However, there are still many issues pertinent to tuberculosis that warrant special consideration regarding isolation, and these are discussed below (see Duration of Isolation in the “Tuberculosis Precautions: Special Considerations” section).


Enteric Precautions

Enteric precautions were used to prevent infections transmitted by feces. Examples would be hepatitis A or bacterial diarrhea. Enteric precautions are now included in Standard Precautions or, in the case of diapered or incontinent patients, Contact Precautions.


Drainage/Secretion Precautions

Drainage/secretion precautions were used to prevent the transmission of infection by direct or indirect contact with drainage from an infected body site or from purulent material. This isolation category was newly created for the 1983 guidelines and used for many infections isolated under wound and skin precautions or discharge and secretion precautions in the previous guideline. Minor skin, wound, or burn infections that can be adequately covered by a dressing previously included in this category are now covered by Standard Precautions. Major infections not covered or not adequately covered by a dressing are now covered under Standard Precautions or Contact Precautions, depending on the clinical setting.


Blood and Body Fluid Precautions

Blood and body fluid precautions were designed to prevent the transmission of blood-borne pathogens. This category is now only for historical reference because Universal Precautions superseded it. Precautions used for blood and body fluids are now recommended in Standard Precautions, which should be used for the care of all patients.


Comments

The advantage of category-specific isolation was that the grouping of diseases with similar routes of transmission was relatively easy to teach to personnel. It consisted of seven categories (six, if blood and body fluid precautions was excluded) that could be adopted, and the diseases grouped accordingly. A disadvantage of the system was that it was diagnosis- or disease recognition-driven and depended on the caregiver to identify the presence or suspected presence of a disease. In addition, drainage/secretion precautions could be confused with contact isolation and vice versa. Universal Precautions recommended barriers to prevent contact with blood and certain body fluids; body substance isolation (BSI) recommends barrier protection for contact with all body fluids or open skin lesions. Because Standard Precautions recommend both, many categories in category-specific isolation are superfluous. Strict isolation, respiratory isolation, and AFB isolation are exceptions but are categorized differently in the new guidelines.



DISEASE-SPECIFIC ISOLATION

Disease-specific isolation was one of two isolation systems recommended by the CDC in 1983 (17). In this system, communicable diseases were considered individually with regard to mode of transmission and infective material, and accordingly, precautions are specified for each disease. The purported advantage of this system is that because precautions are specific for each disease, there are no unnecessary barriers used, and this lowers the cost of isolation. It may also enhance compliance by physicians, who more readily understand the need for specific precautions for each disease. The disadvantage of this system is that because diseases are not grouped by category, it is more difficult to train staff that are not familiar with specific diseases. Another disadvantage is that, like category-specific isolation, this system is diagnosis-driven, and isolation precautions are often important early in the patient’s hospital stay, before a diagnosis is made or even suspected.


IMPACT OF THE ACQUIRED IMMUNODEFICIENCY SYNDROME EPIDEMIC

The recognition of the acquired immunodeficiency syndrome (AIDS) epidemic in the mid-1980s affected isolation policies in healthcare institutions unlike any other event in modern medicine. Before 1987, most hospitals placed patients in isolation, based on diagnosis or suspected diagnosis, according to the category-specific or disease-specific precautions as outlined by the aforementioned CDC guideline (17). As it became apparent that transmission of human immunodeficiency virus (HIV) could occur from patient to healthcare worker, new guidelines were established to minimize exposure to blood-borne pathogens from all patients, not just patients with a diagnosis or suspected diagnosis of HIV infection (18). In contrast to the 1983 CDC guideline, the 1987 CDC document (18) recommended blood and body fluid precautions for all patients, regardless of known HIV status. The belief that such precautions were unnecessary in patients not known to have blood-borne pathogens was gone. Specifically, barrier precautions were recommended to prevent contact with blood, certain body fluids, and body fluids containing blood. The application of blood and body fluid precautions to all patients was referred to as “universal blood and body fluid precautions” or “Universal Precautions.” In 1988, the CDC published an updated Universal Precautions for the prevention of transmission of HIV, hepatitis B virus (HBV), and other blood-borne pathogens to supplement the 1987 publication (19). This document made it clear that transmission of other blood-borne pathogens, such as HBV, should be prevented as well as that of HIV. In a new precedent for the healthcare industry, the Occupational Safety and Health Administration (OSHA) became involved in regulating and enforcing these guidelines (20). Now healthcare institutions were mandated to apply and enforce what was, in effect, blood and body fluid precautions as a minimum standard for protection of the healthcare worker.

Infection control programs recognized the potential benefit of this universal concept as a means of preventing cross-transmitted pathogens (blood-borne and non-bloodborne) among patients and healthcare workers. It became clear very quickly that an additional isolation system was needed to reduce the risk of transmitting non-blood-borne pathogens, because the CDC-defined Universal Precautions were primarily for preventing transmission of blood-borne pathogens. In the CDC 1988 update (19), category-specific or disease-specific isolation precautions are recommended to fill this need, as described in the 1983 CDC guidelines. IPs at Harborview Medical Center in Seattle, Washington, recognized the problem early. They implemented a BSI system at Harborview in 1984 to control cross-transmission of non-blood-borne pathogens. This system designated all body fluids and tissue as potentially infectious (21). In 1987 and 1990, Lynch et al. (22,23) described their system and its advantages in preventing the transmission of both blood-borne and non-blood-borne pathogens. This system provided an alternative to the category-specific or diseasespecific systems. Some confusion ensued because the term Universal Precautions was sometimes used to apply to barrier precautions for all body fluids, not just blood and certain body fluids as originally defined (1,2). Although the 1996 CDC guideline for isolation precautions in hospitals includes concepts of both Universal Precautions and BSI, these isolation systems are described briefly below because of their impact on current practices. Universal Precautions (now part of Standard Precautions) are also described in Chapters 73 and 74.


UNIVERSAL PRECAUTIONS

In 1985 and 1986, the CDC published recommendations to prevent the transmission of HIV in the workplace (24,25). In 1987, a more comprehensive document (18) was published in response to increasing concern from healthcare workers about occupational exposure to HIV. These guidelines recommended the application of blood and body fluid precautions to all patients and designated this policy “Universal Precautions” or “universal blood and body fluid precautions.”

Universal Precautions as presented by the CDC in 1987 (18) include the following concepts:



  • Healthcare workers should use appropriate barrier precautions to avoid skin and mucous membrane exposure when contact with blood or body fluids from any patient is anticipated. Gloves are to be worn for contact with blood and body fluids, mucous membranes, or nonintact skin; when handling surfaces or items soiled with blood or body fluids; or for venipuncture or other procedures involving vascular access. Gloves should be changed after each patient contact. Masks and protective eyewear or face shields should be worn when procedures are likely to generate aerosols or droplets of blood or other body fluids. Gowns should be worn for procedures that are likely to soil clothing.


  • Hands or skin contaminated with blood or body fluids should be washed immediately. Hands should be washed after removing gloves.



  • Precautions should be taken to prevent sharps or needlestick injuries. Needles should not be recapped, removed from disposable syringes, or manipulated by hand. After use, needles, disposable syringes, scalpels, and other disposable sharp instruments should immediately be placed in a designated puncture-resistant container.


  • Mouthpieces and resuscitation devices should be readily available for use in areas where resuscitation procedures may be anticipated.


  • Healthcare workers with exudative skin lesions should not be involved in direct patient care or handle patientcare equipment until the condition has resolved.


Precautions for Invasive Procedures

These were also outlined in the 1987 document and included routine surgical and obstetric procedures and outpatient physician and dentist office procedures. An invasive procedure was defined as surgical entry into tissues, cavities, or organs or repair of major traumatic injuries in an operating or delivery room, emergency department, or outpatient setting, including both physician and dentist offices; cardiac catheterization and angiographic procedures; vaginal or cesarean delivery or other invasive obstetric procedure during which bleeding may occur; or the manipulation, cutting, or removal of any oral or perioral tissues, including tooth structure, during which bleeding occurs or the potential for bleeding exists. Healthcare workers participating in such procedures should routinely use barrier precautions as needed to prevent skin and mucous membrane exposure to blood and body fluids from all patients. This includes not only gloves and surgical masks for invasive procedures but also protective eyewear or face shields for procedures that are anticipated to generate droplets or splashing of blood or body fluids. Effective barrier gowns should be worn when splashing is anticipated. Healthcare workers in obstetrics should use appropriate barrier precautions during deliveries. If a glove is torn or a sharps injury occurs, the glove should be replaced with a new glove. The needle or sharp instrument involved should also be removed from the sterile field.


Precautions for Dentistry

Blood, saliva, and gingival fluid from all dental patients should be considered potentially infective in both institutional and noninstitutional settings. Dental workers should wear gloves for contact with oral mucous membranes and, in addition, surgical masks and protective eyewear or face shields for procedures in which splashing of blood or body fluids is likely. Hand pieces should be sterilized after each patient use. Hand pieces that cannot be sterilized should at least be flushed, cleaned with a chemical germicide, and rinsed after each patient use. Contaminated dental materials (impressions, bite registration) should be cleaned and disinfected before being handled in the dental laboratory and before being placed in another patient’s mouth. Infection control precautions for dentistry are more specifically outlined and updated in later recommendations (26) (see also Chapter 54).


Precautions for Autopsies or Mortician Services

Persons participating in postmortem procedures should wear appropriate barrier protective equipment. Equipment and surfaces contaminated during such procedures should be cleaned with an appropriate chemical germicide (see Chapter 80).


Precautions for Dialysis

Blood and body fluid precautions are to be used when dialyzing all hemodialysis patients, not just those identified as hepatitis B surface antigen positive or HIV positive. HIV-infected patients do not need to be isolated from other patients during hemodialysis. The dialyzer may be discarded after use. Institutions that reuse dialyzers may designate a specific single-use dialyzer to a specific patient for reuse after appropriate cleaning and disinfection on the same patient only. HIV-infected patients may be included in the reuse programs; individual dialyzers must never be used on more than one patient (see also Chapter 63).


Precautions for Laboratories

Blood and other body-fluid specimens from all patients are considered infective. Specimens should be placed in a well-constructed container with a secure lid to avoid leakage. Contamination of the outside of the container or the laboratory form should be avoided. Personnel who process specimens should wear gloves. Other barrier protection should be used as needed if splashing or aerosolization is anticipated. Biologic safety cabinets should be used for procedures that are likely to generate droplets or aerosols. After specimen processing, gloves should be changed and hands washed. Mechanical devices should be used for pipetting; mouth pipetting should never be done. Laboratory work surfaces and laboratory equipment should be decontaminated with an appropriate chemical germicide after blood or body fluid spills and when work is completed. Before leaving the laboratory, personnel should remove protective clothing and wash their hands (see also Chapter 77).


ENVIRONMENTAL CONSIDERATIONS FOR HUMAN IMMUNODEFICIENCY VIRUS TRANSMISSION


Disinfection and Sterilization

Environmental transmission of HIV in the clinical setting has not been documented; however, environmental considerations are reviewed, and the same precautions are recommended for all patients. Standard disinfection and sterilization procedures for equipment are recommended for inpatient and outpatient settings, as previously described in the CDC guidelines for environmental control (27). Semicritical items, or items that contact mucous membranes such as endoscopes and bronchoscopes, should be sterilized or undergo high-level disinfection after each patient use. Chemical germicides registered with the U.S. Environmental Protection Agency (EPA) as sterilants may be used for high-level disinfection or sterilization depending on contact time (see Chapter 80). Under such guidelines, instruments used on HIV-positive patients do not require separate processing because high-level disinfection or sterilization should take place after use on any patient.



Housekeeping

Cleaning of environmental surfaces should be done after contamination by any patient; special cleaning is not required for patients with blood-borne pathogen infections. Horizontal surfaces should be cleaned when spills or soilage occurs and when patients are discharged. EPAregistered disinfectant-detergents should be used. Spills of blood or body fluids should be cleaned up immediately. Personnel should wear gloves. Broken glass and any other sharp objects should first be removed using tongs or forceps and placed in a sharps container. Then, visible fluid should be wiped up, the absorbent materials discarded as infectious waste, and the area decontaminated with a chemical germicide that is tuberculocidal and EPAapproved as a hospital disinfectant. For large spills, the contaminated area should be treated first with the chemical germicide and then cleaned and fresh germicide used for decontamination.


Laundry

Soiled linen should be handled in the same way for all patients with a minimum of agitation; linen should be bagged at the location where it was used. Linen with blood or body-fluid soilage should be transported in leak-proof bags. Linen should be laundered with detergent in hot water (71°C, 160°F) for 25 minutes. If a lower temperature is used, suitable chemicals for low-temperature washing must be used.


Infective Waste

Special precautions are recommended for handling certain hospital wastes that may be infective such as microbiology laboratory waste, pathology waste, and blood specimens or blood products. There has been disagreement on whether to classify communicable disease isolation waste as infectious waste. The CDC does not consider such waste as infectious, but before the Medical Waste Tracking Act of 1988, the EPA classified such waste as infectious waste. In the Medical Waste Tracking Act, however, the EPA modified its position and included only certain highly communicable disease waste from patients with infections due to biosafety level 4 etiologic agents (e.g., viral hemorrhagic fevers, such as Marburg, Lassa, and Ebola) as regulated medical waste (28). Bulk blood, body fluids, or excretions may be disposed of through the sanitary sewer system.


Implementation

These recommendations also stated that employers should ensure that workers receive initial orientation and continuing education and training on the transmission and prevention of blood-borne infections and routine application of Universal Precautions in the care of all patients. Personal protective equipment should be provided by the employer, and monitoring of compliance to the recommended protective measures should be followed.


Other Isolation Categories

With regard to other isolation categories as outlined in the 1983 guideline, the implementation of Universal Precautions superseded the need for a separate category of blood and body fluid precautions. Other isolation precautions, however, were recommended as needed for conditions such as infectious diarrhea (enteric precautions) or tuberculosis (AFB precautions).


UPDATE: UNIVERSAL PRECAUTIONS, 1988

After the recommendations for Universal Precautions were published in 1987, hospitals scurried to write their own institutional policies and implement training for their personnel in the prevention of blood-borne diseases in the workplace. In 1988, the CDC published an update to Universal Precautions that indicated these precautions were also for the prevention of other blood-borne pathogens such as HBV and specified that only specific body fluids implicated in the transmission of blood-borne pathogens needed to be included under Universal Precautions. Many hospitals already had policies in place and employees trained by this time, which contributed to confusion in the use of the term Universal Precautions. A variety of different systems carried this term in individual institutions (29). The 1988 update also included further clarification on the use of protective barriers, the use of gloves for phlebotomy, the selection of gloves, and waste management.


Body Fluids to Which Universal Precautions Apply

In terms of occupational exposures, blood is the most important source of HBV, HIV, and other blood-borne pathogens. Infection prevention efforts aimed at preventing occupationally acquired blood-borne infections must emphasize prevention of exposures to blood and promotion of HBV immunization. Universal Precautions apply to semen, vaginal secretions, cerebrospinal fluid, synovial fluid, pleural fluid, peritoneal fluid, pericardial fluid, amniotic fluid, and any body fluid containing visible blood.


Body Fluids to Which Universal Precautions Do Not Apply

According to the 1988 update, Universal Precautions do not apply to feces, nasal secretions, sputum, sweat, tears, urine, and vomitus unless they contain visible blood. The risk of blood-borne pathogen transmission from these fluids is very low or nonexistent. The 1983 CDC guidelines (category-specific or disease-specific isolation) are cited for the prevention of non-blood-borne pathogen transmission. Universal Precautions do not routinely apply to saliva; however, special precautions are reiterated for dentistry because contamination of saliva with blood is predictable with dental procedures.


Use of Protective Barriers

The types of barriers needed for different procedures and clinical situations vary, so the healthcare worker must use appropriate judgment. Barrier precautions do not prevent sharps injuries; thus, caution in handling needles and sharps instruments, as previously outlined, is also necessary. Protective barriers should be used when exposure to blood or the above-named body fluids is anticipated. Hands or other surfaces contaminated with blood or the specified body fluids should be washed immediately.



Glove Use for Phlebotomy

Although gloves may reduce the amount of blood contaminating hands during venipuncture, they do not prevent needlestick injuries. The likelihood of exposure during phlebotomy depends on the skill of the personnel, the cumulative risk of the worker, whether the procedure is in a routine or emergency setting, and the prevalence of blood-borne pathogens in the patient population. Even though blood from all patients is considered infectious, the prevalence of HIV or HBV in volunteer blood donor centers is known to be low. Some centers, therefore, have not routinely recommended gloves for phlebotomy in these settings. Gloves should always be available for workers who choose to use them, however. Gloves should always be used for phlebotomy when the healthcare worker has scratches, cuts, or other breaks in the skin; when hand contamination with blood is anticipated, such as when phlebotomy is done on an uncooperative patient; for finger or heel sticks on infants or children; and when personnel are receiving phlebotomy training.


Glove Selection

The Center for Devices and Radiological Health, Food and Drug Administration (FDA), is responsible for the regulation of the medical glove industry. Medical gloves include sterile surgical or nonsterile examination gloves made of vinyl or latex. The gloves selected should be task appropriate, and the following are general guidelines. Sterile gloves should be used for contact with sterile body areas. Nonsterile examination gloves may be used for contact with nonsterile body areas or other procedures that do not require aseptic technique. Gloves should be changed between patient contacts. Gloves should not be washed or disinfected between patients. Exposing the gloves to surfactants used for washing may cause increased penetration of liquids through unseen holes in the glove (wicking). Disinfectants may damage the gloves. General-purpose utility gloves (rubber household gloves) should be used for housekeeping activities and instrument cleaning in which contact with blood or specified body fluids is anticipated. These gloves can be reused after decontamination but should be discarded if torn or visibly damaged. Since the publication of this 1988 update, there have been many studies published evaluating glove integrity (see below, “Are Gloves an Effective Barrier?”).


Waste Management

Guidelines on waste management remain unchanged from the 1987 recommendations, but state and local regulations in many areas now supersede these recommendations, and this has been acknowledged.


Comment

Universal Precautions have the advantage of protecting the healthcare worker against unidentified blood-borne pathogen risks. Also, this system is simpler than traditional systems, because the blood and body fluid isolation category applies to all patients. However, the 1988 update, which was intended to clarify which body fluids are infectious, only served to confuse the issue because it is often difficult, at the bedside, to discern whether a body fluid contains blood. Furthermore, it is sometimes difficult to know the origin of a body fluid at the bedside and even more so when the specimen is removed from the bedside. BSI addresses some of these issues. Even so, the issue of cost and compliance in using Universal Precautions may also present a problem (see below, “Impact of Universal Precautions and Body Substance Isolation” section).


BODY SUBSTANCE ISOLATION

Jackson and Lynch (21) responded early on to the concern that unrecognized or undiagnosed cases resulted in unsafe exposures for healthcare workers. As early as 1984, these authors pointed out that many infectious agents are transmitted from patients who have only mild symptoms or no symptoms, and they recommended barrier precautions for anticipated contact with blood or any body fluids from all patients and reemphasized the important role of hand washing. Recognizing the limitations of the diagnosis-driven, category-specific, and disease-specific isolation systems, they systematically outlined an alternative system called BSI (22). This approach was similar to the CDC Universal Precautions in that it presumed that all patients were potentially infectious, but it differed in that barrier precautions are used to prevent contact with all body fluids and tissue, not just certain body fluids and blood-tinged body fluids, as recommended in the 1988 CDC update. The term body substance rather than body fluid is used to emphasize that barrier precautions should be used to prevent contact with solids, such as tissue and feces, and body fluids. BSI contains six major components (22):



  • Gloves should be used for anticipated contact with blood, mucous membranes, nonintact skin, secretions, and moist body substances of all patients. The 1987 article stated that hand washing is not necessary unless hands are visibly soiled from breaks in gloves. Gloves should be changed between patients.


  • After other types of patient contact without gloves, hand washing, which is effective in removing transient flora from the hands, should be done (10 seconds of soap and friction followed by a rinse with running water).


  • Other barriers such as gowns, plastic aprons, masks, or goggles should be worn as needed when soiling of clothing and/or skin or mucous membranes is anticipated.


  • Soiled reusable items, linen, and trash should be contained such that no leakage occurs. Double bagging is not needed unless the outside of the bag is soiled.


  • Needles and sharps should be placed in rigid punctureresistant containers. Needles should not be recapped.


  • Private rooms are indicated for patients with diseases transmissible by the airborne route and for patients who may soil the environment with body substances.


Operational Issues

A single universal reminder sign—“Body substance isolation is for all patient care”—is placed in every patient room or at every bedside. This sign defines body substances and uses graphics and words to indicate when gloves, gowns, masks, or eye protection should be used. A stop sign alert is used on the door of patients with airborne diseases. This sign indicates that persons should check with
the floor nurse before entering the room. The floor nurse will determine if the person is immune and need not wear a mask (e.g., measles, chickenpox) or instruct the person to wear a mask (e.g., tuberculosis). Nonsterile gloves must be accessible near the bedside, and other barriers must be available on the nursing unit. As with Universal Precautions, some judgment by healthcare workers is required in determining when exposures may be anticipated.


Comment

BSI is like Universal Precautions in that it protects workers and patients against the transmission of blood-borne pathogens. BSI is easier to teach to staff and to apply at the bedside than Universal Precautions, as clarified in 1988, because barrier precautions apply to all body fluids not just certain body fluids. BSI has the advantage of protecting against non-blood-borne pathogens as well. Use of gloves has been shown to control cross-transmission of multidrug-resistant enteric gram-negative rods (30). Appropriate use of BSI has indeed been documented to reduce colonization and infection with sentinel microorganisms such as Pseudomonas aeruginosa, Serratia marcescens, and aminoglycoside-resistant gram-negative bacilli (23). In addition, BSI also has the advantage of lessening the psychological trauma of isolation by emphasizing the isolation of body substances rather than the isolation of people (31). That is, because barrier precautions are used for all patients, additional restrictive isolation practices are not needed for most diseases, except those communicable by the respiratory route.

The system, as it was published in 1987, suggested that hand washing was unnecessary when gloves were used for barrier precautions (22). This prompted criticism of the system by those stating that the wearing of gloves for contact with blood or body fluids did not eliminate the need for hand washing (14,32). Studies have documented that hands can be contaminated with microorganisms even though gloves are worn (33,34). When the system was described in later publications, gloving was not emphasized as a substitute for hand washing. In fact, hand washing is recommended when hands are soiled and between patient contacts (23). Many institutions that have adopted BSI require hand washing after glove removal (29).


ARE GLOVES AN EFFECTIVE BARRIER?

At the time of the publication of the 1988 CDC update, there were no published data on the preference of latex versus vinyl gloves. Since that time, there have been numerous studies addressing the integrity of gloves in general and latex versus vinyl gloves in particular. The standards for testing the integrity of latex gloves were established by the American Society for Testing and Materials (ASTM) of the FDA, and compliance with them is voluntary. In 1977, the standard allowed no more than 15 defects per 1,000 (1.5%) sterile unused latex surgical gloves, as determined by the watertight method of testing (35), and 25 defects per 1,000 (2.5%) latex examination gloves (35). In 1989, the FDA method for testing gloves improved, and the standards changed to an allowable defect rate of 2.5% for surgeon’s gloves and 4.0% for examination gloves (36). Due to the continued concern of potential transmission of blood-borne pathogens HIV, HBV, and hepatitis C, the FDA issued a final rule effective December 19, 2008, which further reduced the allowable defect rate for examination gloves to 2.5%. The FDA, using calculated projections based on available CDC data on HIV, HBV, and HCV infections, estimated that this modification in acceptable quality levels could potentially avoid seven cases of HIV infection and seven cases of chronic HBV infection transmitted to healthcare workers over a 10-year period (37).

There are no standards for vinyl gloves. Concern regarding occupational exposure to HIV raised the issue of glove integrity in the clinical setting. In addition, some cases of herpetic whitlow in intensive care unit (ICU) nurses who used gloves focused more attention on this issue (38). Scanning of gloves by electron microscopy has documented inapparent pits from 30 to 50 µm in size, suggesting the possibility that viruses could penetrate this barrier (39).

In addition, several studies have documented leakage rates higher than the ASTM standard of 1.5% to 2.5%. DeGroot-Kosolcharoen and Jones (40) showed that although several brands of sterile latex surgical gloves were impermeable to water and blood, some brands showed leakage rates of up to 8%. Nonsterile latex and vinyl gloves showed leakage rates of 0% to 52%. Nonsterile packaging or packaging in suction kits increased leakage rates. Korniewicz et al. (41) studied gloves stressed by conditions mimicking those encountered in patient care and found that 63% of vinyl gloves leaked a stock solution of bacteriophage compared with 7% of latex gloves. Korniewicz et al. (42) also documented the penetration of 20% of latex gloves and 34% of vinyl gloves by S marcescens. These studies indicate that gloves reduce the risk of gross soilage from blood or body fluids but that they are not 100% effective.

Latex hypersensitivity due to repeated exposure and sensitization of the healthcare worker to latex antigens has led to the adoption of nonlatex gloves made out of various synthetic materials such as neoprene, polyurethane, and nitrile. Korniewicz et al. (43) examined both latex and nonlatex surgical gloves for defects after use by surgeons during surgical procedures and found overall glove defect rates of 5.6% and 7.5% for latex and nonlatex surgical gloves, respectively. Based on the data obtained during this review of surgical gloves, the authors recommended that surgeons change gloves within 2 to 3 hours to avoid exceeding defect rates >5%.

Doebbeling et al. (33) showed that washing gloved hands was not effective for decontamination, and in fact, 5% to 50% of hands were contaminated after gloves were removed. Washing gloves has also been shown to decrease their integrity (44). Thus, gloves should not be washed and reused between patients. These studies affirm that although gloves can be used as a barrier to reduce gross contamination from blood and body fluids, antisepsis after glove removal remains very important because occult breaks in gloves can and do occur.

The surgical literature has long been concerned with perforations in gloves during surgical procedures. In 1899, Bovie (45) stated that careful hand washing was needed, because gloves could be punctured accidentally during an operation.
More recent studies have quantitated the number and location of inapparent perforations that may occur in gloves during surgical or dental procedures. Albin et al. (46) showed a 33% leak rate of latex gloves randomly studied after surgical procedures. These authors also documented a leak rate of up to 5.5% in unused gloves. Gloves studied sequentially showed a leak rate of 58.5% at the end of surgical procedures and 32% at the end of dental procedures. Double gloving decreased the leak rate to 25%. In the sequential surgical study, 52% of the leaks occurred in the first 75 minutes; in the sequential dental study, 75% of the leaks occurred in the first 30 minutes. Gloves used in cardiovascular, orthopedic, abdominal, and oral surgical procedures had leak rates of more than 50%. The frequency of occult glove perforation has been noted to be as high as 10% after interventional radiologic procedures (47). In the Albin et al. study evaluating surgical and dental procedures, leak rates for gloves were evaluated for various members of the surgical team and were found to be highest for the surgeon (52%), followed by the first assistant (29%), and then the scrub nurse (25%) (39). Most perforations (60%) occurred in the thumb or index finger of the glove. Other studies have also documented that the largest number of perforations occur in the thumb, index finger, and middle finger (48,49).


IMPACT OF UNIVERSAL PRECAUTIONS AND BODY SUBSTANCE ISOLATION

Universal Precautions are now a minimum standard in US hospitals as a result of OSHA regulations. Many hospitals also have BSI or some modification of BSI in place because of increasing emphasis on the potential infectiousness of body fluids from all patients and the increasing rate of multidrug-resistant pathogens. To review the advantages of these systems over category-specific or disease-specific isolation, the latter systems may be inconsistently or incorrectly applied, whereas precautions that are used for all patients not only are easier to implement but also protect cross-transmission from patients who may lack signs or symptoms of a disease. Furthermore, there is less psychological trauma for individual patients identified as having a microorganism transmissible by blood or body fluids because all patients are treated in a standard manner. Because of healthcare worker concern about HIV in particular, this system at least theoretically eliminates the need for routine screening of all patients and personnel for HIV at periodic intervals—a process that would prove extremely costly (50).

Some disadvantages of the Universal Precautions concept have been proposed. Because gloves were used more extensively for barrier precautions in BSI and in Universal Precautions, some healthcare workers have sometimes neglected to change gloves between patients (30,32), and such practices have been associated with cross-transmission of microorganisms (51,52). Education and reinforcement of appropriate use of gloves and changing gloves between patients can be successful in reducing such practices (23,51).

The CDC has stated that each institution may design its own system of isolation (17). Indeed, as hospitals have tailored Universal Precautions or BSI to their own institutional needs, each system has incorporated elements of the other and the terms have been used interchangeably, even though there are real and philosophical differences between the two systems (2). Consequently, confusion has ensued regarding the term Universal Precautions in particular (1). The primary purpose of Universal Precautions is to reduce healthcare worker exposure to blood-borne pathogens, whereas the primary intent of BSI is to reduce cross-transmission of microorganisms between patients by transient carriage on the hands of personnel. An additional benefit is the protection of the healthcare worker from the patient’s microorganisms (2).

The effectiveness of Universal Precautions has been evaluated using the frequency of personnel nonparenteral exposures to blood and body fluids (including sputum, urine, feces) as a monitor. Fahey et al. (53) and Wong et al. (54) documented a significant decrease in nonparenteral exposures to blood and body substances after the implementation of Universal Precautions. Saghafi et al. (55) also documented a reduction in exposure of unprotected skin to blood, but the rate of needlestick exposures remained unchanged. So it appears that although Universal Precautions or BSI may significantly reduce nonparenteral exposures to blood or body fluids, other measures such as engineering controls are needed to reduce parenteral exposures such as needlesticks.

As Universal Precautions or BSI systems were implemented throughout the country, glove use increased substantially and cost became a concern. Doebbeling and Wenzel (56) evaluated the costs of using Universal Precautions, and McPherson et al. (57) evaluated the cost of BSI. Universal Precautions increased the total annual costs for isolation materials at a large university teaching hospital by $350,900—an increase, adjusted for inflation, from $13.70 to $22.89 (67%) per admission. Although BSI theoretically could be more costly, it caused an unadjusted increase in cost of 147% for isolation materials compared with an unadjusted increase in cost of 167% for Universal Precautions (56,57). There was an approximately 80% increase in the use of gloves for BSI compared with a 64% increase in glove use for Universal Precautions. Doebbeling and Wenzel (56). estimated that Universal Precautions cost approximately $269 million annually nationwide (using the dollar value from 1989) in hospitals alone and approximately $67 million in the outpatient setting, accounting for $336 million total per year nationwide.

Although these systems are expensive, the alternatives must be considered. The alternative of testing all patients admitted to US hospitals each year is estimated to be $2.6 billion or approximately eight times the cost of Universal Precautions (58). Thus, Universal Precautions are less expensive than universal testing. In addition, a decrease in healthcare-associated infection rates has been documented after the implementation of Universal Precautions and BSI (2,56), providing further evidence for the cost-benefit of these systems in the United States.


Updated CDC Guidelines (1996-2007) and Recent Developments

The CDC’s isolation guidelines were revised by the CDC’s Healthcare Infection Control Practices Advisory Committee and were published in draft guideline format for public comment in 1994 (59) and in final form in 1996 (3).
The guideline contained three important changes from previous recommendations. First, “Standard Precautions” combine the major features of Universal Precautions and BSI. These precautions apply to all patients regardless of diagnosis or known infection status. This first tier of precautions is used to decrease the risk of transmission from recognized or unrecognized infection. Second, the previous categories of isolation (strict isolation, contact isolation, respiratory isolation, enteric precautions, drainage/secretion precautions) and the previous disease-specific precautions are superseded by the three types of transmission-based precautions. These precautions are based on routes of transmission for patients known or suspected to be infected or colonized with highly transmissible or epidemiologically significant pathogens. Third, the new guideline lists specific syndromes in adult and pediatric patients that are suspicious for infection and indicate which precautions to use on an empiric basis pending diagnosis. As with previous guidelines, the CDC recognized that no guideline adequately addresses each hospital’s needs. Individual hospitals and healthcare systems are encouraged to review the recommendations and modify them according to their own needs and resources.

The 2007 guidelines expand the guidance from the 1996 guidelines to include settings outside acute care, such as long-term care and home-based care. In addition, the term healthcare-associated infections has taken the place of “nosocomial infections.” After the 2003 severe acute respiratory syndrome (SARS) and concern for pandemic influenza, respiratory etiquette has been added to the guidelines. There is an update on protective precautions for severely immunocompromised patients and additional recommendations regarding the personal protective equipment necessary to perform certain procedures and environmental and administrative controls required for a safer healthcare environment (4). The 2007 guidelines reiterate Standard Precautions and transmission-based precautions as keystones of infection prevention in healthcare settings (4). Table 90-1 outlines the categorization of diseases by transmissionbased precautions in accordance with these guidelines.

Transmission requires a source of infection, a susceptible host, and a mode of transmission. Transmission-based precautions intend to interrupt this cycle by interfering with the mode of transmission. Sources of infection may include patients, healthcare personnel, and visitors, as well as the environment (60,61,62).

The risk of acquiring healthcare-associated infections varies based on the setting where the patients are located. It is particularly high in the ICUs. In other settings, such as long-term care facilities (LTCFs), patients stay for prolonged periods of time. Patients at LTCFs are encouraged to participate in activities involving other residents, and this may result in increasing the risk of microorganism transmission. The isolation precautions used in acute care may not be practical in an LTCF, and prevention of transmission may be challenging.


What Elements May Help to Prevent Transmission in Healthcare Settings?

To improve the chance of success of any isolation-based precautions, some elements are necessary. These include the presence of healthcare system components that have an influence on the effectiveness of the transmission-based precautions, including adequate infection prevention staffing. A ratio of 1 IP per 250 patients was suggested during the study on the efficacy of nosocomial infection control project (63) and a ratio of 0.8 to 1 IPs per 100 patients on a more recent survey (64). Because of the increased complexity of patients and programs and the shift to ambulatory services, CDC does not recommend a specific ratio but recommends that there be adequate personnel for the complexity of the program. Designated unit nurses may function as infection prevention liaisons who serve as a contact between bedside nurses and IPs, the clinical microbiology laboratory, environmental services, etc. (4,65,66).


General Principles

Hand Hygiene Hand hygiene is the single most important method for preventing healthcare-associated transmission of infection. Despite its importance, compliance with hand hygiene is around 50% to 60% in non-ICU settings and may be even lower in ICUs (around 30%-40%) (67,68,69 and 70).

Such information must encourage, rather than discourage, IPs to continue to reinforce this basic control measure. Easy access to handwashing sinks or antiseptics may increase compliance and should be available, especially in high-risk areas (71). Hands should be washed even when gloves are used, because small tears in the glove may be present and contamination can occur when the glove is removed (3). In addition, failing to change gloves between patients has been implicated in cross-transmission of hospital pathogens (51). Several studies have shown reduced rates of healthcare-associated infections, including those due to resistant pathogens, with improved hand hygiene (72). However, noncompliance with this simple measure has been documented repeatedly (73,74). Risk factors for noncompliance with hand hygiene include being a physician, a nurse aide, male gender, working during the week, using gowns and gloves, automated sink, and performing activities with a high risk of cross-transmission and a high demand for hand washing (i.e., high workload) (75). High workload is a serious problem, particularly in an ICU, where there may be as many as 40 opportunities for hand hygiene in a 1-hour period (76,77).

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Jun 22, 2016 | Posted by in GENERAL & FAMILY MEDICINE | Comments Off on Isolation of Patients With Communicable Diseases

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