In health care facilities, isolation represents one of several measures that can be taken to implement infection control: the prevention of contagious diseases from being spread from a patient to other patients, health care workers, and visitors, or from outsiders to a particular patient (reverse isolation). Various forms of isolation exist, in some of which contact procedures are modified, and others in which the patient is kept away from all others. In a system devised, and periodically revised, by the U.S. Centers for Disease Control and Prevention (CDC), various levels of patient isolation comprise application of one or more formally described "precaution".
Isolation is most commonly used when a patient is known to have a contagious (transmissible person-to-person) viral or bacterial illness. Special equipment is used in the management of patients in the various forms of isolation. These most commonly include items of personal protective equipment (gowns, masks, and gloves) and engineering controls (positive pressure rooms, negative pressure rooms, laminar air flow equipment, and various mechanical and structural barriers). Dedicated isolation wards may be pre-built into hospitals, or isolation units may be temporarily designated in facilities in the midst of an epidemic emergency.
Isolation is defined as the voluntary or compulsory separation and confinement of those known or suspected to be infected with a contagious disease agent (whether ill or not) to prevent further infections. (In this form of isolation, transmission-based precautions are imposed.) In contrast, quarantine is the compulsory separation and confinement, with restriction of movement, of healthy individuals or groups who have potentially been exposed to an agent to prevent further infections should infection occur. Biocontainment refers to laboratory biosafety in microbiology laboratories in which the physical containment (BSL-3, BSL-4) of highly pathogenic organisms is accomplished through built-in engineering controls.
Universal precautions refer to the practice, in medicine, of avoiding contact with patients' bodily fluids, by means of the wearing of nonporous articles such as medical gloves, goggles, and face shields. The practice was widely introduced in 1985–88. In 1987, the practice of universal precautions was adjusted by a set of rules known as body substance isolation. In 1996, both practices were replaced by the latest approach known as standard precautions. Use of personal protective equipment is now recommended in all health settings.
Transmission-based precautions are additional infection control precautions — over and above universal/standard precautions — and the latest routine infection prevention and control practices applied for patients who are known or suspected to be infected or colonized with infectious agents, including certain epidemiologically important pathogens. The latter require additional control measures to effectively prevent transmission.
There are three types of transmission-based precaution:
Strict isolation is used for diseases spread through the air and in some cases by contact. Patients must be placed in isolation to prevent the spread of infectious diseases. Those who are kept in strict isolation are often kept in a special room at the facility designed for that purpose. Such rooms are equipped with a special lavatory and caregiving equipment, and a sink and waste disposal are provided for workers upon leaving the area.
Contact isolation is used to prevent the spread of diseases that can be spread through contact with open wounds. Health care workers making contact with a patient on contact isolation are required to wear gloves, and in some cases, a gown.
Reverse isolation is a way to prevent a patient in a compromised health situation from being contaminated by other people or objects. It often involves the use of laminar air flow and mechanical barriers (to avoid physical contact with others) to isolate the patient from any harmful pathogens present in the external environment.
High isolation is used to prevent the spread of unusually highly contagious, or high consequence, infectious diseases (e.g., smallpox, Ebola virus). It stipulates mandatory use of: (1) gloves (or double gloves if appropriate), (2) protective eyewear (goggles or face shield), (3) a waterproof gown (or total body Tyvek suit, if appropriate), and (4) a respirator (at least FFP2 or N95 NIOSH equivalent), not simply a surgical mask. Sometimes negative pressure rooms or powered air-purifying respirators (PAPRs) are also used.
Isolation can have the following negative effects on patients and staff:
Health care workers who become infected with certain contagious agents may not be permitted to work with patients for a period of time. While facility rules and laws vary from place to place, a common guideline that has been set is 48 hours of removal. Technically, however, this form of infection control is not considered "isolation".