The Centers for Disease Control and Prevention's Hospital Infection Control Practices Advisory Committee promulgates two tiers of precautions: standard and transmission based. Standard precautions assume a broad approach to healthcare personnel and patient protection by including agents transmitted by routes other than blood. Transmission-based precautions are designed for patients with documented or suspected transmissible pathogens for which additional protection beyond standard precautions is required. Transmission-based precautions are of three types: airborne, droplet, and contact. Transmission-based precautions are to be used in addition to, not in place of, standard precautions.2,3,4
Standard precautions are exercised when caring for all patients and include hand washing/sanitization, gloves, mask and eye protection or face shield, gowns, handling of patient care equipment and linens, environmental controls, workplace controls, and patient location or placement depending on the indication.
Hand washing is required after touching blood, body fluids, secretions, excretions, and contaminated items even if gloves are worn. Wash hands immediately after gloves are removed, between patient contacts, and when otherwise indicated to avoid the transfer of organisms to other patients or environments. It may be necessary to wash hands between procedures on the same patient to prevent cross-contamination of different body sites. Plain soap and water are recommended for routine use. Washing with an antimicrobial agent or waterless antiseptic may be done for control of outbreaks or hyperendemic infections, but some pathogens, such as Clostridium difficile,29 are not eradicated by alcohol-based antiseptics.
Use clean, nonsterile gloves when touching blood, body fluids, secretions, excretions, and contaminated items. Change gloves between tasks and procedures involving blood or other potentially infectious materials. Remove gloves and wash hands before touching noncontaminated items or environmental surfaces (e.g., phones, light switches, writing implements) or other patients.
Facemasks, eye protection, and face shields that are fluid resistant are worn to protect mucous membranes of the eyes, nose, and mouth during patient care activities and procedures likely to generate splashes or sprays of blood, body fluids, secretions, excretions, and infectious materials. Replace masks that are soiled, moistened by the user's exhaled vapor, or contaminated by fluids as soon as possible. Protective function may be lost when the barrier device is completely saturated.
Clean, nonsterile gowns that are fluid resistant protect the worker's skin and clothing during patient care activities and procedures likely to generate splashes or sprays of blood, body fluids, secretions, and excretions. Replace soiled gowns as soon as possible because barrier protection is lost if the garment is saturated with contamination. Use sleeve protectors, booties, and leggings if exposure to a large volume of contamination or infectious material is anticipated.
Handle patient care equipment and linens soiled with blood, body fluids, secretions, and excretions specifically to avoid skin and mucous membrane exposure, contamination of clothing, and transfer of microorganisms to other patients and environments. Reusable items should be cleaned and reprocessed to eliminate infectivity. Promptly discard single-use items.
ENVIRONMENTAL AND WORK PRACTICE CONTROLS
Environmental controls include hospital procedures for the decontamination of objects in patient care areas. Clean and disinfect environmental surfaces, beds, bed rails, bedside equipment, and frequently touched surfaces between patient uses.
Workplace controls (work practice controls) include proper disposal of needles, scalpels, and other sharp instruments. Avoid recapping, excessive handling, and manipulation of sharp devices. Use self-sheathing devices and puncture-resistant containers, and replace sharps containers before they overflow. Patients who contaminate the environment or those who cannot assist in their own hygiene should be located in a private room if available.
In addition to standard precautions, use airborne precautions for patients known or suspected of being infected with microorganisms transmitted by airborne droplet nuclei. Airborne precautions also apply to small-particle (<5 μm) residue of evaporated droplets containing microorganisms that remain suspended in the air and can be widely dispersed by air currents. Examples of infectious agents spread by this method are found in Table 162-11.2
TABLE 162-11Airborne-Spread Infectious Diseases ||Download (.pdf) TABLE 162-11 Airborne-Spread Infectious Diseases
Varicella (including disseminated zoster)
Isolate ED patients requiring airborne precautions in an airborne infection isolation room with (1) monitored negative air pressure in relation to surrounding areas, (2) 6 to 12 air changes per hour, and (3) discharge of the room air to the outdoors or high-efficiency filtration of the air before it is circulated to other areas in the hospital. The patient must remain in the isolation room with the door closed. Limit the movement in and out of the room and transportation of the patient. When movement is unavoidable, the patient should wear respiratory protection to avoid contamination of other areas within the hospital. Healthcare workers entering the room must wear respiratory protection, such as a personalized, fitted mask with efficient filters (approved particulate respirator).
In addition to standard precautions, use droplet precautions for patients known to have or suspected of having serious illnesses transmitted by large particle droplets (>5 μm). Droplets are generated during talking, sneezing, or coughing and during the performance of procedures. Examples of infectious agents spread by this method are listed in Table 162-12.2,4
TABLE 162-12Droplet-Spread Infectious Diseases ||Download (.pdf) TABLE 162-12 Droplet-Spread Infectious Diseases
Invasive Haemophilus influenzae type B (including meningitis, pneumonia, epiglottitis, sepsis)
Invasive Neisseria meningitidis (including meningitis, pneumonia, sepsis)
Serious bacterial respiratory infections
Streptococcal pharyngitis, pneumonia, scarlet fever
Serious viral infections
Influenza (including H1N1)
Place the patient in a private room when possible. Prioritize patients with excessive cough and sputum production to available single-patient rooms. Special air handling and ventilation are not required, and the door may remain open. If a private room is not available, the patient may be placed in a room with other patients who have active infections with the same microorganism (i.e., cohorting). If cohorting is also not possible, place a mask on the patient and maintain a spatial separation of at least 3 ft (1 m) between the infected patient and other patients and visitors. Avoid placing patients with droplet precautions in the same room with patients at increased risk for adverse outcomes from infection. Limit the movement and transportation of patients with droplet precautions. When movement is required, place a face mask on the patient. Healthcare workers should wear face masks when working within 3 ft (1 m) of the patient. Healthcare workers should wear respiratory protection equivalent to a fitted N95 filtering respirator or higher level of protection during aerosol-generating procedures such as suctioning. Change protective attire and perform hand hygiene between contacts with all patients.
In addition to standard precautions, use contact precautions when patients are known to have or suspected of having serious illnesses transmitted by direct patient contact or contact with items in the patient's environment. Examples of such infectious diseases are shown in Table 162-13.2,4
TABLE 162-13Contact-Spread Infectious Diseases ||Download (.pdf) TABLE 162-13 Contact-Spread Infectious Diseases
Multidrug-resistant infections or colonization (GI, respiratory, skin, wound sites)
Enteric infections with low infective dose or prolonged environmental survival
Enterohemorrhagic Escherichia coli O157:H7
Respiratory syncytial virus
Skin infections that are highly contagious or that may occur on dry skin:
Herpes simplex virus (neonatal or mucocutaneous)
Major, noncontained abscesses, cellulitis, decubiti
Herpes zoster (disseminated or in an immunocompromised host)
Viral hemorrhagic conjunctivitis
Viral hemorrhagic infections (Ebola, Lassa, Marburg, Crimean-Congo hemorrhagic fever)
Change gloves whenever the examination and care of a patient result in contact with infectious materials and a high concentration of microorganisms (wound drainage or fecal material). When expecting contact with infectious materials (incontinence, dressing changes, attention to colostomy), wear a clean, nonsterile gown and gloves. Remove the gown and gloves before leaving the care area. Wash hands with an antimicrobial agent or waterless antiseptic after removal of gloves, and avoid contact with potentially contaminated environmental surfaces or items in the room after hand washing.
Limit transportation and movement of the patient. When movement is required, cover contaminated areas with large, bulky dressings. Bulky, adsorbent, leakproof dressings contain contaminated secretions and limit spread of disease.
Durable, multiuse medical equipment (e.g., blood pressure cuffs, stethoscopes, bedside commodes) should be dedicated to a single patient (or cohort of similarly infected patients). Personnel who use personal medical equipment (e.g., stethoscopes) should thoroughly clean these items between patient contacts to avoid contamination.