Isolation refers to the precautions that are taken in the hospital to preventthe spread of an infectious agent from an infected or colonized patient to susceptible persons. Isolation practices are designed to minimize the transmission of infection in the hospital, using current understanding of the way infections can transmit. Isolation should be done in a user friendly, well-accepted, inexpensive way that interferes as little as possible with patient care,minimizes patient discomfort, and avoids unnecessary use.
The type of precautions used should be viewed as a flexible scale that may range from the least to the most demanding methods of prevention. These methodsshould always take into account that differences exist in the way that diseases are spread. Recognition and understanding of these differences will avoiduse of insufficient or unnecessary interventions.
Isolation practices can include placement in a private room or with a selectroommate, the use of protective barriers such as masks, gowns and gloves, a special emphasis on handwashing (which is always very important), and specialhandling of contaminated articles. Because of the differences among infectious diseases, more than one of these precautions may be necessary to prevent spread of some diseases but may not be necessary for others.
The Centers for Disease Control and Prevention (CDC) and the HospitalInfection Control Practice Advisory Committee (HICPAC) have led the way in defining the guidelines for hospital-based infection precautions. The most current system recommended for use in hospitals consists of two levels of precautions. The first level is Standard Precautions which apply to all patients atall times because signs and symptoms of infection are not always obvious andtherefore may unknowingly pose a risk for a susceptible person. The second level is known as Transmission-Based Precautions which are intended for individuals who have a known or suspected infection with certain organisms.
Frequently, patients are admitted to the hospital without a definite diagnosis, but with clues to suggest an infection. These patients should be isolatedwith the appropriate precautions until a definite diagnosis is made.
Standard Precautions define all the steps that should be taken to prevent spread of infection from person to person when there is an anticipated contact with:
- Body fluids
- Secretions, such as phlegm
- Excretions, such as urine and feces (not including sweat) whether or not they contain visible blood
- Nonintact skin, such as an open wound
- Mucous membranes, such as the mouth cavity.
Standard Precautions includes the use of one or combinations of the followingpractices. The level of use will always depend on the anticipated contact with the patient:
- Handwashing, the most important infection control method
- Use of latex or other protective gloves
- Masks, eye protection and/or face shield
- Proper handling of soiled patient care equipment
- Proper environmental cleaning
- Minimalhandling of soiled linen
- Proper disposal of needles and other sharpequipment such as scalpels
- Placement in a private room for patientswho cannot maintain appropriate cleanliness or contain body fluids.
Transmission Based Precautions may be needed in addition to Standard Precautions for selected patients who are known or suspected to harbor certain infections. These precautions are divided into three categories that reflect the differences in the way infections are transmitted. Some diseases may require more than one isolation category.
Airborne Precautions prevent diseases that are transmitted by minute particles called droplet nuclei or contaminated dust particles. These particles, because of their size, can remain suspended in the air for long periods of time;even after the infected person has left the room. Some examples of diseases requiring these precautions are tuberculosis, measles, and chickenpox.
A patient needing Airborne Precautions should be assigned to a private room with special ventilation requirements. The door to this room must be closed atall possible times. If a patient must move from the isolation room to another area of the hospital, the patient should be wearing a mask during the transport. Anyone entering the isolation room to provide care to the patient mustwear a special mask called a respirator.
Droplet Precautions prevent the spread of organisms that travel on particlesmuch larger than the droplet nuclei. These particles do not spend much time suspended in the air, and usually do not travel beyond a several foot range from the patient. These particles are produced when a patient coughs, talks, orsneezes. Examples of disease requiring droplet precautions are meningococcalmeningitis (a serious bacterial infection of the lining of the brain), influenza, mumps, and German measles (rubella).
Patients who require Droplet Precautions should be placed in a private room or with a roommate who is infected with the same organism. The door to the room may remain open. Health care workers will need to wear masks within three feet of the patient. Patients moving about the hospital away from the isolation room should wear a mask.
Contact Precautions prevent spread of organisms from an infected patient through direct (touching the patient) or indirect (touching surfaces or objects that that been in contact with the patient) contact. Examples of patients whomight be placed in Contact Precautions are those infected with:
- Antibiotic-resistant bacteria
- Hepatitis A
This type of precaution requires the patient to be placed in a private room or with a roommate who has the same infection. Health care workers should weargloves when entering the room. They should change their gloves if they touchmaterial that contains large volumes of organisms such as soiled dressings.Prior to leaving the room, health care workers should remove the gloves and wash their hands with medicated soap. In addition, they may need to wear protective gowns if there is a chance of contact with potentially infective materials such as diarrhea or wound drainage that cannot be contained or if there is likely to be extensive contact with the patient or environment.
Patient care items, such as a stethoscope, that are used for a patient in Contact Precautions should not be shared with other patients unless they are properly cleaned and disinfected before reuse. Patients should leave the isolation room infrequently.