Health care-associated infections (HAIs) are infections that patients acquire during the course of receiving treatment for other conditions. Health care workers can also get HAIs while performing their duties within the health care setting. HAIs result from aerobic or anaerobic bacteria, viruses, parasites, or fungi. (See Infectious diseases possibly acquired in health care facilities.) They occur most commonly in the urinary and lower respiratory tracts, bloodstream, and surgical sites. Urinary tract infections most commonly result from catheter insertion, urogenital surgery, or instrumentation. Respiratory tract infections usually result from aspiration of oropharyngeal secretions, inhalation of airborne pathogens from other patients or caregivers, contaminated ventilation equipment, or lung seeding from blood-borne pathogens. Surgical site infection may result from contamination during surgery, preexisting medical conditions, skin damage during preoperative preparation (such as shaving), or impaired blood supply.

The risk of HAIs increases with the patient’s age, underlying medical condition, length of hospitalization, and use of invasive devices.

Infection control practices have evolved continuously since JCAHO and the American Hospital Association issued a statement in 1958 advising that every accredited
health care facility must have an infection control committee and a monitoring system as part of a formal infection control program. AHOSPA OSHA

Twelve years later, in 1970, the Centers for Disease Control and Prevention (CDC) published a guide to isolation techniques in hospitals; the guide was updated in 1975, 1983, and again in 1996. In 1980, the CDC released Guidelines for the Prevention and Control of Nosocomial Infections. The guidelines had two purposes: to disseminate advice on prevention or control of specific nosocomial infection problems and to cover the questions most frequently asked of the CDC’s Division of Healthcare Quality Promotion staff. (See Infection control timeline.)

An atmosphere of concern regarding the transmission of human immunodeficiency virus brought about the expansion of isolation guidelines to include protective measures, such as wearing gloves, masks, gowns, and goggles to guard against exposure to blood and body fluids. The expanded guidelines, released
in 1985, were called universal precautions. Body substance isolation guidelines, concerning the handling and disposal of potentially infectious body substances, were introduced in 1987.

In 1996, the CDC instituted standard precautions, which combined major features of blood and body fluid precautions with practices regarding body substance isolation. Standard precautions recommend that health care workers wear appropriate protective clothing or use appropriate protective equipment when the duty being performed requires or may involve contact with any body substance, mucous membrane, or broken skin. The CDC also added three other categories called transmission-based precautions — airborne precautions, droplet precautions, and contact precautions.

Airborne precautions, used in addition to standard precautions, prevent the spread of infectious diseases transmitted by droplet nuclei 5 μm or smaller that are breathed, sneezed, or coughed into the environment. (See Indications for airborne precautions.) Diseases in this category include the former categories of acid-fast bacillus isolation and respiratory isolation.

To effectively guard against the spread of infection from an airborne transmitted infection, an isolation patient requires a monitored negative-pressure room with the door kept closed to maintain the proper air pressure balance in the isolation room, the anteroom, and the adjoining hallway or corridor. The air should undergo 12 air exchanges per hour for new construction and 6 air exchanges per hour for construction before
2001. EB2 It should be appropriately discharged directly to the outside of the building or filtered through high-efficiency particulate air (HEPA) filtration before it’s circulated to other areas of the health care facility. If for some reason a private room isn’t available, patients infected with the same disease can share a room, but consultation with infection control professionals is advised before patient placement.

All persons who enter the room must wear respiratory protection. In 1993, the Centers for Disease Control and Prevention (CDC) published tuberculosis guidelines recommending the use of a disposable respirator, such as an N95 respirator or HEPA respirator; a reusable respirator, such as a HEPA respirator; or a powered air-purifying respirator (PAPR) that provides protection against microorganisms transmitted by airborne droplet nuclei. Regardless of the type of respirator used, the health care worker must make sure that the respirator properly fits her face, covering the mouth and nose, each time she wears it. Fit testing of all respirators ensures proper fit. OSHA If the patient must leave the room for an essential procedure, he should wear a surgical mask to cover his nose and mouth while out of the room, and personnel in the area where the patient is going should be notified and instructed to take airborne precautions.

Contact precautions prevent the spread of infectious diseases transmitted by direct or indirect contact with the patient (skin-to-skin), patient-care items (bedpans, urinals), or indirect contact with surfaces in the patient’s room that are contaminated with the infectious microorganism. (See Indications for contact precautions.)

The Centers for Disease Control and Prevention (CDC) recommends that contact precautions apply to patients who are known or suspected to be infected or colonized (presence of microorganism without obvious clinical signs and symptoms of infection) with epidemiologically important organisms that can be transmitted by direct or indirect contact. Effective contact precautions require a private room. If no private room is available, two patients infected with the same (but no other) microorganism can share a room.

CDC guidelines advise considering the epidemiology of the microorganism and the patient population and consulting infection control professionals before patient placement.

Anyone having contact with the patient, the patient’s support equipment, or items soiled with the patient’s bodily fluids should wear clean, nonsterile gowns and gloves. Gloves should be changed after contact with infective material that may contain high concentrations of the microorganism, such as fecal material or wound drainage. A gown and gloves should be removed before leaving the patient’s room. Thorough hand washing with an antimicrobial agent or waterless antiseptic agent and proper handling and disposal of contaminated items are also essential in maintaining contact precautions.

Patient transport should be limited to essential purposes only. If the patient is transported, make sure that precautions are maintained to decrease the risk of transmission to other patients and contamination of environmental surfaces.

When possible, medical and noncritical patient-care equipment (I.V. pumps, monitors) should be used for only one patient. If sharing equipment is unavoidable, then items must be properly cleaned or disinfected before use with another patient.