Contact precautions are a series of procedures designed to minimize the transmission of infectious organisms by direct or indirect contact with an infected patient or his environment. Along with standard precautions, which assume all body fluids and tissues are potentially infected with harmful microorganisms, contact precautions require the use of protective equipment such as disposable gowns, gloves, and masks when exposure to a patient's body fluids is anticipated. Contact precautions are often used with patients who have wound or skin infections.
A series of contact precautions has been formulated by the United States Centers for Disease Control and Prevention (CDC) and are intended to minimize the risk of the direct or indirect transfer of disease-causing (pathogenic) microorganisms. Direct-contact transmission involves person-to-person contact such as when a patient is touched by a healthcare provider. Indirect transfer involves contact with items that have been in contact with an infected person and which have become contaminated. These items, which are termed fomites, include clothing, towels, and utensils. A fomite may be only transiently contaminated by an infectious microbe, or the pathogen may actually colonize the object.
It has been known for centuries that infection and hygiene are connected. More than 2,000 years ago, Hippocrates, who laid the groundwork for today's medical practices, observed that physicians’ cleanliness affected their patients’ health. Centuries later, Joseph Lister demonstrated in the mid-nineteenth century that spraying a disinfectant over a patient's wound during an operation reduced post-operative complications and death considerably. This was subsequently shown to be due to the protection of the wound from airborne microbes.
Microorganisms are readily transferred from one location to another via surfaces. The surface can be living, such as the skin of someone's hand, or non-living, such as a piece of equipment or clothing. Care must be taken to ensure that contact with a patient involves surfaces that are free of disease-causing (pathogenic) microorganisms.
The current CDC contact precautions have been in place since January 1996, as part of the overall Guideline for Isolation Procedures in Hospitals. Periodically, the guidelines are reviewed and, if necessary, revised.
WORDS TO KNOW
ANTIBIOTIC RESISTANCE: The ability of bacteria to resist the actions of antibiotic drugs.
FOMITE: A fomite is an object or a surface to which an infectious microorganism such as bacteria or viruses can adhere and be transmitted. Transmission is often by touch.
PATHOGENIC: Something causing or capable of causing disease.
STANDARD PRECAUTIONS: Standard precautions are the safety measures taken to prevent the transmission of disease-causing bacteria. These include proper handwashing, wearing gloves, goggles, and other protective clothing, proper handling of needles, and sterilization of equipment.
A fundamental contact precaution is handwashing. Proper washing with an anti-microbial soap will kill bacteria that are present on the surface of the skin, including normal residents of the skin such as Staphylococcus aureus and bacteria in the genus Streptococcus. Bacteria that are normally present on the skin will only be removed for a short time, but this will be long enough to protect patients. The physical act of washing, with the friction of skin rubbing against skin, helps remove viruses, provided it is done long enough. A few seconds of handwashing before surgery is dangerous, while a few minutes can save a life.
The CDC guidelines specify that handwashing be accomplished before and after contact with a patient and, if gloves are worn, as the final action after the gloves have been properly disposed of.
Fresh gloves need to be put on when contacting a patient for the first time. If various locations are to be touched on a patient, then the order should be from the least to the most contaminated, to minimize transfer of microbes to a relatively clean site. Gloves should be disposed of in a container designed for that purpose.
The high death rate following surgery that was the norm in the early decades of the nineteenth century was traced to the habit of physicians of wearing the same blood-soaked operating gowns during their rounds from patient to patient. Essentially, the physician was incubating each patient in turn with the collective microbial population that was adhering to the gown. To be an effective safety measure, disposable gloves, masks, and gowns are worn prior to seeing a patient and discarded in a designated container after seeing the patient. Containers should be available in each patient ward, so that the used protective clothing can be discarded in that room and not elsewhere on the hospital floor. This reduces the likelihood of transferring an infection from one room to another.
Another CDC-mandated contact precaution is to limit patient transport in the hospital as much as possible. A patient requiring contact precautions should only be moved when necessary, such as to an operating theater or X-ray room. Then, transport should be done to minimize contact with other patients. For example, a patient should not be moved into a hallway and kept there for a period of time before being transported to the final destination. Rather, transport should be direct and prompt. The more a patient is moved, the more the chance that an infection can be transferred from that patient to others.
When contact precautions are used, medical equipment such as blood pressure monitors, stethoscopes, or IV poles are dedicated solely to one patient, not shared. When contact precautions are discontinued, the equipment is cleaned and disinfected before use on another patient. Standards for the cleaning and disinfection of equipment, and for monitoring the success of these decontamination procedures, exist and must be followed. As well, records of equipment cleaning and maintenance must be kept, which makes it easier to investigate the source of a disease outbreak.
Only 150 years ago, surgery was almost a death sentence. The cause of this dismal record was the inadvertent contamination of the patient by people whose task it was to ensure their care and recovery. Since then, precautions that minimize patient exposure to dangerous microbes has vastly improved the quality of health care.
Still, problems remain. The spread of antibiotic resistant bacteria such as methicillin-resistant S. aureus (MRSA) in hospital wards shows that person-to-person transfer is still a reality. A big part of this problem remains the lack of proper handwashing by health care providers. Surveys done among health care providers in the United States, Canada, Europe, and elsewhere have revealed that nurses wash their hands correctly only about 50% of the time, with physicians being even less careful. The use of alcohol-based hand sanitizers, which are effective after only a few seconds exposure on the skin, is helping to encourage more compliance with handwashing by busy healthcare staff.
Contact precautions such as handwashing and wearing protective clothing are also important when dealing with a patient with diseases caused by antibiotic-resistant bacteria such as MRSA and bacteria that have developed resistance to the antibiotic vancomycin. Improper contact precautions can allow the bacteria to spread to both fellow patients and health care workers.
Black, Jacquelyn. Microbiology: Principles and Explorations. New York: John Wiley & Sons, 2004.
Tierno, Philip M. The Secret Life of Germs: What They Are, Why We Need Them, and How We Can Protect Ourselves Against Them. New York: Atria, 2004.
Yale-New Haven Hospital. “Contact Precautions.” <http://www.med.yale.edu/ynhh/infection/contact/contact.html> (accessed May 27, 2007).