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Recommendations for Isolation Precautions in Hospitals*
RATIONALE FOR ISOLATION PRECAUTIONS IN HOSPITALS
Transmission of infection within a hospital requires three elements: a source of infecting microorganisms, a susceptible host, and a means of transmission for the microorganism.
Placing a patient on isolation precautions, however, often presents certain disadvantages to the hospital, patients, personnel, and visitors. Isolation precautions may require specialized equipment and environmental modifications that add to the cost of hospitalization. Isolation precautions may make frequent visits by nurses, physicians, and other personnel inconvenient, and they may make it more difficult for personnel to give the prompt and frequent care that sometimes is required. The use of a multi-patient room for one patient uses valuable space that otherwise might accommodate several patients. Moreover, forced solitude deprives the patient of normal social relationships and may be psychologically harmful, especially to children. These disadvantages, however, must be weighed against the hospital’s mission to prevent the spread of serious and epidemiologically important microorganisms in the hospital.
Human sources of the infecting microorganisms in hospitals may be patients, personnel, or, on occasion, visitors, and may include persons with acute disease, persons in the incubation period of a disease, persons who are colonized by an infectious agent but have no apparent disease, or persons who are chronic carriers of an infectious agent. Other sources of infecting microorganisms can be the patient’s own endogenous flora, which may be difficult to control, and inanimate environmental objects that have become contaminated, including equipment and medications.
Resistance among persons to pathogenic microorganisms varies greatly. Some persons may be immune to infection or may be able to resist colonization by an infectious agent; others exposed to the same agent may establish a commensal relationship with the infecting microorganism and become asymptomatic carriers; still others may develop clinical disease. Host factors such as age; underlying diseases; certain treatments with antimicrobials, corticosteroids, or other immunosuppressive agents; irradiation; and breaks in the first line of defense mechanisms caused by such factors as surgical operations, anesthesia, and indwelling urinary and central venous catheters (urinary catheters and central venous catheters) may render patients more susceptible to infection.
The classic definition of transmission is an appraisal of how classes of pathogens cause infection. Simply stated, microorganisms are transmitted in hospitals by several routes, and the same microorganism may be transmitted by more than one route. There are three common modes of transmission: contact, droplet, and airborne. Within this context, health-care providers need to differentiate between nosocomial infection and health-care-associated infection (HAI). The term nosocomial infection refers to those infections that are acquired in a hospital, whereas an HAI can be acquired from delivery of care in multiple settings including, hospitals, long-term care, ambulatory care, or home care. The difference between the two terms is that in nosocomial infections we know the infection was acquired in the hospital. With HAI we know that the infection was acquired somewhere along the health-care path, we are just not sure exactly when or where. An example would be an individual who moves from home care, to acute care, to long-term care. Additional modes of transmission are common vehicle and vectorborne, which will be discussed briefly for the purpose of this guideline as neither play a significant role in the typical nosocomial or HAI infections.
- Contact transmission, the most important and frequent mode of transmission of nosocomial or HAI infections, is divided into two subgroups: direct-contact transmission and indirect-contact transmission.
- 1a. Direct-contact transmission involves a direct body surface-to-body surface contact and physical transfer of microorganisms between a susceptible host and an infected or colonized person. In the health-care setting, this occurs most frequently between patient and health-care personnel through a mucous membrane crack or ungloved patient contact with infected/infested skin. Examples of such contacts can include turning a patient, giving a patient a bath, or performing other patient-care activities that require direct contact. Direct-contact transmission also can occur between two patients, with one serving as the source of the infectious microorganisms and the other as a susceptible host.
- 1b.Indirect-contact transmission involves contact of a susceptible host with a contaminated intermediate object, usually inanimate, such as contaminated instruments, needles, dressings, or shared patient care devices such as glucose monitoring machines. For children, those inanimate objects can even include toys. Other sources are insufficient hand hygiene, or gloves that are not changed between patients, as well as soiled clothing such as uniforms or laboratory coats have been found to be a source for indirect-contact transmission. Multidrug-resistant organisms (MDRO) are a special concern in health-care settings. Transmission usually occurs patient-to-patient by the hands of health-care workers.
- Droplet transmission, theoretically, is a form of contact transmission. However, the mechanism of transfer of the pathogen to the host is quite distinct from either direct- or indirect-contact transmission. Therefore, droplet transmission is considered a separate route of transmission in this guideline. Historically droplet size is defined as being 5 μm or greater. Droplets are generated from the source person primarily during coughing, sneezing, and talking, and during the performance of certain procedures such as suctioning and bronchoscopy. Transmission occurs when droplets containing microorganisms generated from the infected person are propelled a short distance through the air and deposited on the host’s conjunctivae, nasal mucosa, or mouth. The general rule of thumb has been that droplets will travel approximately 3 ft from the source to the host. However, studies suggest that droplets from organisms such as smallpox and severe acute respiratory distress syndrome (SARS) can travel a distance of 6 ft or more from source to host. Therefore the suggested distance of 3 ft is considered to be a recommendation rather a mandate. As a result, distance should not be the only criteria used to decide whether or not the use of a mask is appropriate. Because droplets do not remain suspended in the air, special air handling and ventilation are not required to prevent droplet transmission; that is, droplet transmission must not be confused with airborne transmission.
- Airborne transmission occurs by dissemination of either airborne droplet nuclei (small-particle residue [5 μm or smaller in size] of evaporated droplets containing microorganisms that remain suspended in the air for long periods of time) or dust particles containing the infectious agent. Microorganisms carried in this manner can be dispersed widely by air currents and may become inhaled by a susceptible host within the same room or over a longer distance from the source patient, depending on environmental factors; therefore, special air handling and ventilation such as an airborne infection isolation room are required to prevent airborne transmission. Microorganisms transmitted by airborne transmission include Mycobacterium tuberculosis, Aspergillus spp., and the rubeola and varicella viruses.
- Common vehicle transmission applies to microorganisms transmitted by contaminated items such as food, water, medications, devices, and equipment.
- Vector-borne transmission occurs when vectors such as mosquitoes, flies, rats, and other vermin transmit microorganisms; this route of transmission is of less significance in hospitals in the United States than in other regions of the world.
Isolation precautions are designed to prevent transmission of microorganisms by these routes in hospitals. Because agent and host factors are more difficult to control, interruption of transfer of microorganisms is directed primarily at transmission. This goal can be more readily achieved by having an infection control nurse assist in the implementation of policies at the unit level; adequate staff with minimal use of outside staff; clinical laboratory support to promptly report important organisms or outbreak concerns; implementation of a culture of safety within the organization; adherence of health-care workers to recommended infection control guidelines; surveillance for HAIs; and continuing education of health-care workers, patients, and families. The recommendations presented in this guideline are based on this concept.
FUNDAMENTALS OF ISOLATION PRECAUTIONS
A variety of infection control measures are used for decreasing the risk of transmission of microorganisms in hospitals. These measures make up the fundamentals of isolation precautions. Examples of personal protective equipment (PPE) used in infection control include gloves, gowns, masks, goggles, and shoe covers.
Hand Hygiene and Gloving
Hand hygiene is frequently called the single most important measure to reduce the risks of transmitting organisms from one person to another or from one site to another on the same patient. The concept of hand hygiene includes hand washing, or in the absence of visible soiling, the use of approved alcohol-based products for hand disinfecting. The scientific rationale, indications, methods, and products for hand washing are delineated in other publications.
Hand washing or the use of alcohol-based products should be completed as promptly and thoroughly as possible between patient contacts and after contact with blood, body fluids, secretions, and excretions. Hand hygiene should also occur after contact with equipment or articles contaminated by blood, fluids, secretions, or excretions. Such hygiene is an important component of infection control and isolation precautions. In addition to hand hygiene, gloves play a key role in reducing the risks of microorganism transmission. The effectiveness of hand hygiene can be reduced by health-care workers wearing artificial nails as they can harbor pathogenic organisms. It is recommended that health-care workers who provide direct patient care be restricted from wearing these nails.
Gloves are worn for three important reasons in hospitals. First, gloves are worn to provide a protective barrier and to prevent gross contamination of the hands when touching blood, body fluids, secretions, excretions, mucous membranes, and nonintact skin; the wearing of gloves in specified circumstances to reduce the risk of exposures to bloodborne pathogens is mandated by the Occupational Safety and Health Administration (OSHA) bloodborne pathogens final rule. Second, gloves are worn to reduce the likelihood that microorganisms present on the hands of personnel will be transmitted to patients during invasive or other patient-care procedures that involve touching a patient’s mucous membranes and nonintact skin. Third, gloves are worn to reduce the likelihood that hands of personnel contaminated with microorganisms from a patient or a fomite can transmit these microorganisms to another patient. In this situation, gloves must be changed between patient contacts and hands washed after gloves are removed.
Wearing gloves does not replace the need for hand hygiene, because gloves may have small, inapparent defects or may be torn during use, and hands can become contaminated during removal of gloves. Changing gloves is recommended when provision of care requires touching equipment that is moved from room to room. Failure to change gloves between patient contacts is an infection control hazard.
Appropriate patient placement is a significant component of isolation precautions. A private room is important to prevent direct- or indirect-contact transmission when the source patient has poor hygienic habits, contaminates the environment, or cannot be expected to assist in maintaining infection control precautions to limit transmission of microorganisms (e.g., infants, children, and patients with altered mental status). When possible, a patient with highly transmissible or epidemiologically important microorganisms is placed in a private room with hand washing and toilet facilities to reduce opportunities for transmission of microorganisms.
When a private room is not available, an infected patient is placed with an appropriate roommate. Patients infected by the same microorganism usually can share a room, provided they are not infected with other potentially transmissible microorganisms and the likelihood of reinfection with the same organism is minimal. Such sharing of rooms, also referred to as cohorting patients, is useful especially during outbreaks or when there is a shortage of private rooms. When a private room is not available and cohorting is not achievable or recommended, it is very important to consider the epidemiology and mode of transmission of the infecting pathogen and the patient population being served in determining patient placement. Under these circumstances, consultation with infection control professionals is advised before patient placement. Moreover, when an infected patient shares a room with a noninfected patient, it also is important that patients, personnel, and visitors take precautions to prevent the spread of infection and that roommates are selected carefully.
Guidelines for construction, equipment, air handling, and ventilation for isolation rooms are delineated in other publications. A private room with appropriate air handling and ventilation is particularly important for reducing the risk of transmission of microorganisms from a source patient to susceptible patients and other persons in hospitals when the microorganism is spread by airborne transmission. Some hospitals use an isolation room with an anteroom as an extra measure of precaution to prevent airborne transmission. Adequate data regarding the need for an anteroom, however, is not available. Ventilation recommendations for isolation rooms housing patients with pulmonary tuberculosis have been delineated in other Centers for Disease Control and Prevention (CDC) guidelines.
Transport of Infected Patients
Limiting the movement and transport of patients infected with virulent or epidemiologically important microorganisms and ensuring that such patients leave their rooms only for essential purposes reduces opportunities for transmission of microorganisms in hospitals. When patient transport is necessary, it is important that (1) appropriate barriers (e.g., masks, impervious dressings) are worn or used by the patient to reduce the opportunity for transmission of pertinent microorganisms to other patients, personnel, and visitors and to reduce contamination of the environment; (2) personnel in the area to which the patient is to be taken are notified of the impending arrival of the patient and of the precautions to be used to reduce the risk of transmission of infectious microorganisms; and (3) patients are informed of ways by which they can assist in preventing the transmission of their infectious microorganisms to others.
Masks, Respiratory Protection, Eye Protection, Face Shields
Various types of masks, goggles, and face shields are worn alone or in combination to provide barrier protection. A mask that covers both the nose and the mouth, as well as goggles or a face shield are worn by hospital personnel during procedures and patient-care activities that are likely to generate splashes or sprays of blood, body fluids, secretions, or excretions to provide protection of the mucous membranes of the eyes, nose, and mouth from contact transmission of pathogens. The use of masks also protects the patient from exposure to organisms from health-care workers during sterile procedures, and protects health-care workers and others from exposure to coughing patients. The wearing of masks, eye protection, and face shields in specified circumstances to reduce the risk of exposures to bloodborne pathogens is mandated by the OSHA bloodborne pathogens final rule. A surgical mask generally is worn by hospital personnel to provide protection against spread of infectious large-particle droplets that are transmitted by close contact and generally travel only short distances (up to 3 ft) from infected patients who are coughing or sneezing.
An area of major concern and controversy over the last several years has been the role and selection of respiratory protection equipment and the implications of a respiratory protection program for prevention of transmission of tuberculosis in hospitals. Traditionally, although the efficacy was not proven, a surgical mask was worn for isolation precautions in hospitals when patients were known or suspected to be infected with pathogens spread by the airborne route of transmission. In 1990, however, the CDC tuberculosis guidelines stated that surgical masks may not be effective in preventing the inhalation of droplet nuclei and recommended the use of disposable particulate respirators, despite that the efficacy of particulate respirators in protecting persons from the inhalation of M. tuberculosis had not been demonstrated. By definition, particulate respirators included dust-mist (DM), dust-fume-mist (DFM), or high-efficiency particulate air (HEPA) filter respirators certified by the CDC National Institute for Occupational Safety and Health (NIOSH); because the generic term “particulate respirator” was used in the 1990 guidelines, the implication was that any of these respirators provided sufficient protection.
In 1993, a draft revision of the CDC tuberculosis guidelines outlined performance criteria for respirators and stated that some DM or DFM respirators might not meet these criteria. After review of public comments, the guidelines were finalized in October 1994, with the draft respirator criteria unchanged. At that time, the only class of respirators that were known to consistently meet or exceed the performance criteria outlined in the 1994 tuberculosis guidelines and that were certified by NIOSH (as required by OSHA) were HEPA filter respirators. Subsequently, NIOSH revised the testing and certification requirements for all types of air-purifying respirators, including those used for tuberculosis control. The new rule, effective in July 1995, provides a broader range of certified respirators that meet the performance criteria recommended by the CDC in the 1994 tuberculosis guidelines. NIOSH has indicated that the N95 (N category at 95% efficiency) meets the CDC performance criteria for a tuberculosis respirator. Current recommendations encourage health-care care workers to undergo fit-testing. The goal of fit-testing is to ensure that the health-care worker’s respirator (N95 mask) fits well during job performance. The frequency of fit-testing has not been specified. Generally fit-testing should be repeated when there is a change in facial features, a change in mask model or sizing, and for any condition effecting the health-care worker’s respiratory function. During testing, it is important to assess these salient points: mask positioning and fit across the nose, cheeks, and chin, with room for eye protection, and room to talk. Additional information on the evolution of respirator recommendations, regulations to protect hospital personnel, and the role of various federal agencies in respiratory protection for hospital personnel has been published.
Gowns and Protective Apparel
Various types of gowns and protective apparel are worn to provide barrier protection and to reduce opportunities for transmission of microorganisms in hospitals. Gowns are worn to prevent contamination of clothing and to protect the skin of personnel from blood and body fluid exposures. Gowns specially treated to make them impermeable to liquids, leg coverings, boots or shoe covers provide greater protection to the skin when splashes or large quantities of infective material are present or anticipated. Gowns should cover the arms, torso, and legs to mid-thigh, providing complete coverage of these areas. Remove gowns cautiously to prevent contamination of clothing. Gowns and all other PPE should be removed and discarded prior to leaving the patient’s room. The wearing of gowns and protective apparel under specified circumstances to reduce the risk of exposures to bloodborne pathogens is mandated by the OSHA bloodborne pathogens final rule (Categories IB/IC).
Gowns are also worn by personnel during the care of patients infected with epidemiologically important microorganisms to reduce the opportunity for transmission of pathogens from patients or items in their environment to other patients or environments; when gowns are worn for this purpose, they are removed before leaving the patient’s environment and hands are washed. Adequate data regarding the efficacy of gowns for this purpose, however, are not available.
Patient-Care Equipment and Articles
Many factors determine whether special handling and disposal of used patient-care equipment and articles are prudent or required, including the likelihood of contamination with infective material; the ability to cut, stick, or otherwise cause injury (needles, scalpels, and other sharp instruments [sharps]); the severity of the associated disease; and the environmental stability of the pathogens involved. Some used articles are enclosed in containers or bags to prevent inadvertent exposures to patients, personnel, and visitors and to prevent contamination of the environment. Used sharps are placed in puncture-resistant containers; other articles are placed in a bag. One bag is adequate if the bag is sturdy and the article can be placed in the bag without contaminating the outside of the bag; otherwise, two bags are used.
The scientific rationale, indications, methods, products, and equipment for reprocessing patient-care equipment are delineated in other publications. Contaminated reusable critical medical devices or patient-care equipment (i.e., equipment that enters normally sterile tissue or through which blood flows) or semicritical medical devices or patient-care equipment (i.e., equipment that touches mucous membranes) are sterilized or disinfected (reprocessed) after use to reduce the risk of transmission of microorganisms to other patients; the type of reprocessing is determined by the article and its intended use, the manufacturer’s recommendations, hospital policy, and any applicable guidelines and regulations.
Noncritical equipment (i.e., equipment that touches intact skin) contaminated with blood, body fluids, secretions, or excretions is cleaned and disinfected after use, according to hospital policy. Contaminated disposable (single-use) patient-care equipment is handled and transported in a manner that reduces the risk of transmission of microorganisms and decreases environmental contamination in the hospital; the equipment is disposed of according to hospital policy and applicable regulations.
Linen and Laundry
Although soiled linen may be contaminated with pathogenic microorganisms, the risk of disease transmission is negligible if it is handled, transported, and laundered in a manner that avoids transfer of microorganisms to patients, personnel, and environments. Rather than rigid rules and regulations, hygienic and common sense storage and processing of clean and soiled linen are recommended. The methods for handling, transporting, and laundering of soiled linen are determined by hospital policy and any applicable regulations.
Dishes, Glasses, Cups, and Eating Utensils
No special precautions are needed for dishes, glasses, cups, or eating utensils. Either disposable or reusable dishes and utensils can be used for patients on isolation precautions. The combination of hot water and detergents used in hospital dishwashers is sufficient to decontaminate dishes, glasses, cups, and eating utensils.
Routine and Terminal Cleaning
The room, or cubicle, and bedside equipment of patients on Transmission-Based Precautions are cleaned using the same procedures used for patients on Standard Precautions, unless the infecting microorganism(s) and the amount of environmental contamination indicates special cleaning. In addition to thorough cleaning, adequate disinfection of bedside equipment and environmental surfaces (e.g., bedrails, bedside tables, carts, commodes, doorknobs, faucet handles) is indicated for certain pathogens, especially enterococci, which can survive in the inanimate environment for prolonged periods of time. Patients admitted to hospital rooms that previously were occupied by patients infected or colonized with such pathogens are at increased risk of infection from contaminated environmental surfaces and bedside equipment if they have not been cleaned and disinfected adequately. The methods, thoroughness, and frequency of cleaning and the products used are determined by hospital policy.
HOSPITAL INFECTION CONTROL PRACTICES ADVISORY COMMITTEE (HICPAC) ISOLATION PRECAUTIONS
There are two tiers of HICPAC isolation precautions: first Standard Precautions, and second Transmission-Based Precautions. In the first, and most important, tier are those precautions designed for the care of all patients in hospitals, regardless of their diagnosis or presumed infection status. Implementation of these “Standard Precautions” is the primary strategy for successful nosocomial infection control. In the second tier are precautions designed only for the care of specified patients. These additional Transmission-Based Precautions are for patients known or suspected to be infected by epidemiologically important pathogens spread by airborne or droplet transmission or by contact with dry skin or contaminated surfaces.
Standard Precautions synthesize the major features of Universal Precautions (UP) and Body Substance Isolation (BSI) under the premise that transmissible infections agents can be contained in multiple care situations and apply to all patients receiving care in any health-care setting, regardless of their diagnosis or presumed infection status. Standard Precautions apply to (1) blood; (2) all body fluids, secretions, and excretions except sweat, regardless of whether they contain visible blood; (3) nonintact skin; and (4) mucous membranes. Standard Precautions are designed to reduce the risk of transmission of microorganisms from both recognized and unrecognized sources of infection in hospitals. Basic Standard Precautions include the use of gown, mask, gloves, and goggles or face shield as appropriate. Three new recommendations focused on patient protection have been added to Standard Precaution guidelines: (1) Respiratory Hygiene/Cough Etiquette, (2) mask use for catheter insertion/injection (spinal, epidural), and (3) safe injection practices.
Respiratory Hygiene/Cough Etiquette was developed as a response to SARS focusing on patients and family members who enter the health-care setting with undiagnosed respiratory symptoms including cough, congestion, runny nose, and productive secretions. There are five basic goals associated with Respiratory Hygiene/Cough Etiquette: (1) to educate interceding staff, family, patients, and visitors when a high-risk patient enters the health-care setting with regard to description of respiratory symptoms, the importance of reporting symptoms, description of the types and use of PPE; (2) to communicate information regarding respiratory hygiene and cough etiquette via posted instructions in appropriate languages; (3) to enforce source control measures (covering mouth when coughing or sneezing, proper disposal of contaminated tissues, appropriate use of surgical masks by the coughing individual); (4) to enforce effective hand hygiene; and (5) to maintain a distance of 3 to 6 ft or more from source person if PPE is not being used.
Protection with mask use during spinal procedures (epidural injection or catheter placement) is recommended to prevent contamination from oropharyngeal droplets causing infection. The October 2005 HICPAC concluded that there is sufficient evidence to support this recommended change in practice.
Safe injection focuses on preventing pathogen outbreaks from ineffective infection control practice. Conceptually, emphasis is placed on aseptic technique with use of sterile single-use needles and syringes, use of disposable needles, use of single rather than multiple dose vials, and prevention of contamination of injection devices and medication. Emphasis is placed on the training and retraining of aseptic technique and infection control practices.
Transmission-Based Precautions are designed for patients documented or suspected to be infected with highly transmissible or epidemiologically important pathogens for which additional precautions beyond Standard Precautions are needed to interrupt transmission in hospitals. There are three types of Transmission-Based Precautions: Airborne Precautions (or Airborne Infection Isolation Precautions [AIIR]), Droplet Precautions, and Contact Precautions. They may be combined for diseases that have multiple routes of transmission. When used either singularly or in combination, they are to be used in addition to Standard Precautions.
Airborne Precautions are designed to reduce the risk of airborne transmission of infectious agents. Airborne transmission occurs by dissemination of either airborne droplet nuclei (small-particle residue [5 μm or smaller in size] of evaporated droplets that may remain suspended in the air for long periods of time) or dust particles containing the infectious agent. Microorganisms carried in this manner can be dispersed widely by air currents and may become inhaled by or deposited on a susceptible host within the same room or over a longer distance from the source patient, depending on environmental factors; therefore, special air handling and ventilation are required to prevent airborne transmission. Airborne Precautions apply to patients known or suspected to be infected with epidemiologically important pathogens that can be transmitted by the airborne route.
Droplet Precautions are designed to reduce the risk of droplet transmission of infectious agents. Droplet transmission involves contact of the conjunctivae or the mucous membranes of the nose or mouth of a susceptible person with large-particle droplets (larger than 5 μm in size) containing microorganisms generated from a person who has a clinical disease or who is a carrier of the microorganism. Droplets are generated from the source person primarily during coughing, sneezing, or talking and during the performance of certain procedures such as suctioning and bronchoscopy. Transmission via large-particle droplets requires close contact between source and recipient persons because droplets do not remain suspended in the air and generally travel only short distances. General rule of thumb has been that droplets will carry through the air a distance of usually 3 or fewer feet. However, evidence suggests that some droplets such as chickenpox or SARS can carry as far as 6 ft from their source. Therefore the suggested distance of 3 ft should be considered an example of how far a droplet can carry from the source to the host rather than an exact measurement. Because droplets do not remain suspended in the air, special air handling and ventilation are not required to prevent droplet transmission. Droplet Precautions apply to any patient known or suspected to be infected with epidemiologically important pathogens that can be transmitted by infectious droplets.
Contact Precautions are designed to reduce the risk of transmission of epidemiologically important microorganisms by direct or indirect contact. Contact precautions also apply in the presence of fecal incontinence, excessive wound drainage, and any other body secretions that may indicate a contamination/transmission risk. Direct-contact transmission involves skin-to-skin contact and physical transfer of microorganisms to a susceptible host from an infected or colonized person, such as occurs when personnel turn patients, bathe patients, or perform other patient-care activities that require physical contact. Direct-contact transmission also can occur between two patients (e.g., by hand contact), with one serving as the source of infectious microorganisms and the other as a susceptible host. Indirect-contact transmission involves contact of a susceptible host with a contaminated intermediate object, usually inanimate, in the patient’s environment. Contact Precautions apply to specified patients known or suspected to be infected or colonized (presence of microorganism in or on patient but without clinical signs and symptoms of infection) with epidemiologically important microorganisms than can be transmitted by direct or indirect contact.
EMPIRIC USE OF AIRBORNE, DROPLET, OR CONTACT PRECAUTIONS
In many instances, the risk of nosocomial transmission of infection may be highest before a definitive diagnosis can be made and before precautions based on that diagnosis can be implemented. The routine use of Standard Precautions for all patients should greatly reduce this risk for conditions other than those requiring Airborne, Droplet, or Contact Precautions. Although it is not possible to prospectively identify all patients needing these enhanced precautions, certain clinical syndromes and conditions carry a sufficiently high risk to warrant the empiric addition of enhanced precautions (Transmission-Based Precautions), whereas a definitive diagnosis is pursued and test recommendations are required to institute Transmission-Based Precautions in these instances until test results are obtained.
Immunocompromised patients vary in their susceptibility to nosocomial infections, depending on the severity and duration of immunosuppression. They generally are at increased risk for bacterial, fungal, parasitic, and viral infections from both endogenous and exogenous sources. The use of Standard Precautions for all patients and Transmission-Based Precautions for specified patients, as recommended in this guideline, should reduce the acquisition by these patients of institutionally acquired bacteria from other patients and environments. A new prevention strategy called Protective Environment has been designed to protect this type of patient, (specifically hematiopoietic stem cell patients) by decreasing environmental exposure risk in the days immediately after transplant.
It is beyond the scope of this guideline to address the various measures that may be used for immunocompromised patients to delay or prevent acquisition of potential pathogens during temporary periods of neutropenia. Rather, the primary objective of this guideline is to prevent transmission of pathogens from infected or colonized patients in hospitals. Users of this guideline, however, are referred to the “Guideline for Prevention of Nosocomial Pneumonia” (95, 96) for the HICPAC recommendations for prevention of nosocomial aspergillosis and Legionnaires’ disease in immunocompromised patients.
The recommendations presented below are categorized as follows:
Category IA. Strongly recommended for all hospitals and strongly supported by well-designed experimental or epidemiological studies.
Category IB. Strongly recommended for all hospitals and reviewed as effective by experts in the field and a consensus of HICPAC based on strong rationale and suggestive evidence, even though definitive scientific studies have not been done.
Category IC. Mandated for implementation in health-care settings by state or federal standards/regulation.
Category II. Suggested for implementation in many hospitals. Recommendations may be supported by suggestive clinical or epidemiological studies, a strong theoretical rationale, or definitive studies applicable to some, but not all, hospitals.
No recommendation; unresolved issue. Practices for which insufficient evidence or consensus regarding efficacy exists.
The recommendations are limited to the topic of isolation precautions. Therefore, they must be supplemented by hospital policies and procedures for other aspects of infection and environmental control, occupational health, administrative and legal issues, and other issues beyond the scope of this guideline.
- Administrative Control
Ensure transmission prevention is incorporated into organizational objectives and occupational safety programs with development of appropriate policies and procedures. Transmission prevention strategies should be supported fiscally, with human resource including infection control staff and programs, laboratory resources for surveillance, and investigation. The presence of HAI’s should provide some direction for staffing and decontamination decisions with the assistance of infection control in design, detection strategies, and monitoring of performance measures. (Categories IA/IB/IC/II)
Develop a system to ensure that hospital patients, personnel, and visitors are educated about use of precautions and their responsibility for adherence to them. (Category IB/IC)
- Adherence to Precautions
Periodically evaluate adherence to precautions, and use findings to direct improvements. (Category IB)
- Standard Precautions
Implementation of Standard Precautions is based on the assumption that all patients are a potential source of transmissible infection. Adherence to state and federal law in provision of protection for health-care personnel is required. (Category IC)
- Hand Hygiene
(1) Perform hand hygiene after touching blood, body fluids, secretions, excretions, nonintact skin, and contaminated items; immediately after gloves are removed; prior to direct patient contact; between patient contacts; and when otherwise indicated to prevent transfer of microorganisms to other patients or environments. Hand hygiene may be necessary between tasks or procedures on the same patient to prevent cross contamination of different body sites. Wash hands with an antimicrobial soap, or plain (nonantimicrobial) soap and water when visibly soiled. An alcohol-based hand rub may be used in the absence of visible soiling or after soiling has been removed with plain (nonantimicrobial) soap and water. Artificial nails or extenders are not to be worn by individuals providing direct patient contact. (Categories IA/IB/IC/II)
(2) Use a plain (nonantimicrobial) soap for routine hand washing. (Category IB)
(3) Use an antimicrobial agent or a waterless antiseptic agent for specific circumstances (e.g., control of outbreaks or hyperendemic infections), as defined by the infection control program. (Category IB) (See Contact Precautions for additional recommendations on using antimicrobial and antiseptic agents.)
Wear gloves (clean, nonsterile gloves are adequate) when touching blood, body fluids, secretions, excretions, and contaminated items. Put on clean gloves just before touching mucous membranes and nonintact skin. Change gloves between tasks and procedures on the same patient after contact with material that may contain a high concentration of microorganisms. Remove gloves promptly after use, before touching noncontaminated items and environmental surfaces, and before going to another patient, and wash hands immediately to avoid transfer of microorganisms to other patients or environments. (Category IB)
- Mask, Eye Protection, Face Shield
Wear a mask and eye protection or a face shield to protect mucous membranes of the eyes, nose, and mouth during procedures and patient-care activities that are likely to generate splashes or sprays of blood, body fluids, secretions, and excretions. (Category IB)
Wear a gown (a clean, nonsterile gown is adequate) to protect skin and to prevent soiling of clothing during procedures and patient-care activities that are likely to generate splashes or sprays of blood, body fluids, secretions, or excretions. Select a gown that is appropriate for the activity and amount of fluid likely to be encountered. Remove a soiled gown as promptly as possible, and wash hands to avoid transfer of microorganisms to other patients or environments. (Category IB)
- Patient-Care Equipment
Handle used patient-care equipment soiled with blood, body fluids, secretions, and excretions in a manner that prevents skin and mucous membrane exposures, contamination of clothing, and transfer of microorganisms to other patients and environments. Ensure that reusable equipment is not used for the care of another patient until it has been cleaned and reprocessed appropriately. Ensure that single-use items are discarded properly. (Category IB)
- Environmental Control
Ensure that the hospital has adequate procedures for the routine care, cleaning, and disinfection of environmental surfaces, beds, bedrails, bedside equipment, and other frequently touched surfaces, and ensure that these procedures are being followed. (Category IB)
Handle, transport, and process used linen soiled with blood, body fluids, secretions, and excretions in a manner that prevents skin and mucous membrane exposures and contamination of clothing, and that avoids transfer of microorganisms to other patients and environments. (Category IB)
- Occupational Health and Bloodborne Pathogens
(1) Take care to prevent injuries when using needles, scalpels, and other sharp instruments or devices; when handling sharp instruments after procedures; when cleaning used instruments; and when disposing of used needles. Never recap used needles, or otherwise manipulate them using both hands, or use any other technique that involves directing the point of a needle toward any part of the body; rather, use either a one-handed “scoop” technique or a mechanical device designed for holding the needle sheath. Do not remove used needles from disposable syringes by hand, and do not bend, break, or otherwise manipulate used needles by hand. Place used disposable syringes and needles, scalpel blades, and other sharp items in appropriate puncture-resistant containers, which are located as close as practical to the area in which the items were used, and place reusable syringes and needles in a puncture-resistant container for transport to the reprocessing area. (Category IB) (2) Use mouthpieces, resuscitation bags, or other ventilation devices as an alternative to mouth-to-mouth resuscitation methods in areas where the need for resuscitation is predictable. (Category IB)
- Patient Placement
Place a patient who contaminates the environment or who does not (or cannot be expected to) assist in maintaining appropriate hygiene or environmental control in a private room. If a private room is not available, consult with infection control professionals regarding patient placement or other alternatives. (Category IB)
- Hand Hygiene
- Airborne Precautions
In addition to Standard Precautions, use Airborne Precautions, or the equivalent, for patients known or suspected to be infected with microorganisms transmitted by airborne droplet nuclei (small-particle residue [5 μm or smaller in size] of evaporated droplets containing microorganisms that remain suspended in the air and that can be dispersed widely by air currents within a room or over a long distance). (Category IB)
- Patient Placement
Place the patient in a private room that has (1) monitored negative air pressure in relation to the surrounding areas, (2) 6 to 12 air changes per hour, and (3) appropriate discharge of air outdoors or monitored high-efficiency filtration of room air before the air is circulated to other areas in the hospital. Keep the room door closed and the patient in the room. When a private room is not available, place the patient in a room with a patient who has active infection with the same microorganism, unless otherwise recommended, but with no other infection. When a private room is not available and cohorting is not desirable, consultation with infection control professionals is advised before patient placement. (Category IB)
- Respiratory Protection
Wear respiratory protection (N95 respirator) when entering the room of a patient with known or suspected infectious pulmonary tuberculosis. Susceptible persons should not enter the room of patients known or suspected to have measles (rubeola) or varicella (chickenpox) if other immune caregivers are available. If susceptible persons must enter the room of a patient known or suspected to have measles (rubeola) or varicella, they should wear respiratory protection (N95 respirator). Persons immune to measles (rubeola) or varicella need not wear respiratory protection. (Category IB)
- Patient Transport
Limit the movement and transport of the patient from the room to essential purposes only. If transport or movement is necessary, minimize patient dispersal of droplet nuclei by placing a surgical mask on the patient, if possible. (Category IB)
- Additional Precautions for Preventing Transmission of Tuberculosis: Consult the Centers for Disease Control and Prevention’s “Guidelines for Preventing the Transmission of Tuberculosis in Health-Care Facilities” for additional prevention strategies.
- Patient Placement
- Droplet Precautions
In addition to Standard Precautions, use Droplet Precautions, or the equivalent, for a patient known or suspected to be infected with microorganisms transmitted by droplets (large-particle droplets [larger than 5 μm in size] that can be generated by the patient during coughing, sneezing, talking, or the performance of procedures). (Category IB)
- Patient Placement
Place the patient in a private room. When a private room is not available, place the patient in a room with a patient(s) who has active infection with the same microorganism but with no other infection (cohorting). When a private room is not available and cohorting is not achievable, maintain spatial separation of at least 3 ft between the infected patient and other patients and visitors. Special air handling and ventilation are not necessary, and the door may remain open. (Category IB)
In addition to wearing a mask as outlined under Standard Precautions, wear a mask when working within 3 ft of the patient. (Logistically, some hospitals may want to implement the wearing of a mask to enter the room.) (Category IB)
- Patient Transport
Limit the movement and transport of the patient from the room to essential purposes only. If transport or movement is necessary, minimize patient dispersal of droplets by masking the patient, if possible. (Category IB)
- Patient Placement
- Contact Precautions
In addition to Standard Precautions, use Contact Precautions, or the equivalent, for specified patients known or suspected to be infected or colonized with epidemiologically important microorganisms that can be transmitted by direct contact with the patient (hand or skin-to-skin contact that occurs when performing patient-care activities that require touching the patient’s dry skin) or indirect contact (touching) with environmental surfaces or patient-care items in the patient’s environment. (Category IB)
- Patient Placement
Place the patient in a private room. When a private room is not available, place the patient in a room with a patient(s) who has active infection with the same microorganism but with no other infection (cohorting). When a private room is not available and cohorting is not achievable, consider the epidemiology of the microorganism and the patient population when determining patient placement. Consultation with infection control professionals is advised before patient placement. (Category IB)
- Gloves and Hand Hygiene
In addition to wearing gloves as outlined under Standard Precautions, wear gloves (clean, nonsterile gloves are adequate) when entering the room. During the course of providing care for a patient, change gloves after having contact with infective material that may contain high concentrations of microorganisms (fecal material and wound drainage). Remove gloves before leaving the patient’s room and wash hands immediately with an antimicrobial agent or a waterless antiseptic agent. After glove removal and hand washing, do not touch potentially contaminated environmental surfaces or items in the patient’s room to avoid transfer of microorganisms to other patients or environments. (Category IB)
In addition to wearing a gown as outlined under Standard Precautions, wear a gown (a clean, nonsterile gown is adequate) when entering the room if you anticipate that your clothing will have substantial contact with the patient, environmental surfaces, or items in the patient’s room, or if the patient is incontinent or has diarrhea, an ileostomy, a colostomy, or wound drainage not contained by a dressing. Remove the gown before leaving the patient’s environment. After gown removal, ensure that clothing does not contact potentially contaminated environmental surfaces to avoid transfer of microorganisms to other patients or environments. (Category IB)
- Patient Transport
Limit the movement and transport of the patient from the room to essential purposes only. If the patient is transported out of the room, ensure that precautions are maintained to minimize the risk of transmission of microorganisms to other patients and contamination of environmental surfaces or equipment. (Category IB)
- Patient-Care Equipment
When possible, dedicate the use of noncritical patient-care equipment to a single patient (or cohort of patients infected or colonized with the pathogen requiring precautions) to avoid sharing between patients. If use of common equipment or items is unavoidable, then adequately clean and disinfect them before use for another patient. (Category IB)
- Additional Precautions for Preventing the Spread of Vancomycin Resistance
Consult the HICPAC report on preventing the spread of vancomycin resistance for additional prevention strategies.
- Patient Placement
*SOURCE: Adapted from http://www.cdc.gov/ncidod/dhqp/gl_isolation.html.