Personal Protective Equipment
Personal Protective Equipment
Personal protective equipment is equipment used in a healthcare setting to prevent direct contact with infectious microorganisms or contact with body fluids that might contain a disease-causing (pathogenic) microorganism.
Gloves, gowns or aprons, masks and respirators, goggles, and face shields are all examples of personal protective equipment. The degree of protection offered by such equipment varies depending on the infectious disease being dealt with. Treating someone who has a common cold may only require the use of medical gloves, for example, while a public health response to the dispersal of Bacillus anthracis (the cause of anthrax) requires personnel to wear full body suits, including sealed gloves and respirators that block the inhalation of the tiny bacterial spores.
The use of personal protective equipment is centuries old. Records from England dating back to the seventeenth century describe the protective headgear, gowns, and masks worn by physicians treating plague victims. At the time, some physicians assumed that plague could be transmitted through the air. Although scientists later discovered that plague is caused by a bacterium called Yersinia pestis that is transmitted by the bite of an infected flea, the use of protective clothing was a wise precaution.
Through the early decades of the nineteenth century, surgeons did not wear any special clothing when they performed operations. Surgeries were done by physicians who literally walked in off the street into an open-air operating theater. The realization that dedicated surgical clothing prevented the transmission of infections from patient to patient revolutionized medicine and made post-surgical infections less common. In this sense, the clothing was protective to the patient. However, with time the protective value of clothing to healthcare providers also was recognized.
Then as now, the premise of personal protective equipment is simple—protective clothing and other gear presents a barrier to the transmission of infectious microorganisms.
WORDS TO KNOW
BIOSAFETY LEVEL 4 FACILITY: A specially equipped, secured laboratory where scientists study the most dangerous known microbes. These labs are designed to contain infectious agents and disease-causing microbes, prevent their dissemination, and protect researchers from exposure.
MICROORGANISM: Microorganisms are minute organisms. With the single yet-known exception of a bacterium that is large enough to be seen unaided, individual microorganisms are microscopic in size. To be seen, they must be magnified by an optical or electron microscope. The most common types of microorganisms are viruses, bacteria, blue-green bacteria, some algae, some fungi, yeasts, and protozoans.
PATHOGEN: A disease-causing agent, such as a bacteria, virus, fungus, etc.
RESPIRATOR: A respirator is any device that assists a patient in breathing or takes over breathing entirely for them.
The types of personal protective equipment used depend on a number of factors. One factor is the setting. For example, a researcher at a biosafety level 4 facility, which is designed to deal with dangerously contagious microorganisms, must be completely enclosed in a protective suit that is connected to an air supply. On the other hand, a general practitioner who is examining a person who has a cold may only elect to wear a face mask as a barrier to virusladen droplets that could be expelled by a cough.
Another factor is the anticipated type of exposure. More extensive face and body coverage is required if there is the potential for splashing or spraying of body fluids, for example. Related to this is the appropriateness of the protective equipment for the task. For example, when confronting a dangerous respiratory infection, a respirator can be more appropriate than a mask, since the respirator is designed to exclude small droplets that can pass through the mask fabric. As a second example, an apron that does not absorb liquids is a safer choice when dealing with a victim of Ebola (where a great deal of bleeding usually occurs) than a surgical gown made of absorbent cotton.
A third factor is the fit of the protective equipment. One size does not fit all. Trying to care for a patient or respond to a medical emergency while wearing protective equipment that is too small or too large is certainly inconvenient and can be dangerous. Ill-fitting protective gear may restrict movement and, in the case of a respirator that is too large and fits sloppily on the face, may render the equipment useless.
Gloves are the most common personal protective equipment in hospitals and other healthcare settings. The choice of glove depends on the task. Gloves are available in a variety of materials, may be sterile (free of microorganisms) or non-sterile, and may be intended for single use or repeated use. However, gloves are only as effective as the person wearing them. For example, if a healthcare provider fails to change gloves after leaving one patient and moving on to treat another patient, infections may be spread. Even when treating a single patient, a healthcare worker should change gloves after examining a body site that is infected and before examining other non-infected sites on the same patient.
The use of approved respirators are required when dealing with certain infections. One example is tuberculosis. The bacterium that is responsible for the respiratory infection (Mycobacterium tuberculosis) can be expelled inside small droplets, which can be inhaled by someone close by the patient. N95, N99, and N100 respirators are designed to exclude droplets that are less than 5 microns (a micron is one-millioneth of a meter) in diameter. Avian influenza—a potentially lethal infection caused by the H5N1 virus that has evolved to include the capability of person-to-person transmission—is another infection that requires a healthcare provider to use a respirator.
IN CONTEXT: TERRORISM AND BIOLOGICAL WARFARE
Fear of bioterrorism, periodically heightened by news events, sometimes causes panic buying of equipment that may be illdesigned to meet real threats. For example, military surplus gas masks generally provide only the illusion of protection. They offer no real protection against biological agents and should not be bought for that purpose. Personnel stockpiling of antibiotics is also unwise. The potency of antibiotics such as Cipro declines with time. Moreover, the inappropriate use of antibiotics can actually lead to the development of bacterial resistance and a consequential lowering of antibiotic effectiveness.
General preparedness is always prudent. A few days supply of food and water and the identification of rooms in homes and offices that can be temporarily sealed with duct tape to reduce outside air infiltration is a wise precaution. More specific response plans and protective measures, however, must be based upon the specific dangers posed by organisms that produce disease. For example, Anthrax (Bacillus anthracis), Botulism (Clostridium botulinum toxin), Plague (Yersinia pestis), Smallpox (Variola major), Tularemia (Francisella tularensis), viral hemorrhagic fevers (e.g., Ebola, Marburg), and arenaviruses (e.g., Lassa) are considered high-risk potential bioterrorism agents. These agents share a common trait of being easily spread from person to person. And they all can kill many of those who are infected. However, the natures of the diseases they cause are very different. A response that is effective against one microorganism may well be useless against another.
When properly used and worn, personal protective equipment is an efficient means of minimizing the spread of infectious disease from those who are infected to their healthcare providers, and, via the healthcare provider, to other patients. For example, before surgeons began to wear surgical garments, operations were a last resort due to the high post-surgical death rate. When surgeons began to wear special clothing that was changed between operations, the rate of post-surgical infection decreased dramatically. Today, the Occupational Safety and Health Administration enforces the Bloodborne Pathogens Standard, last updated in 2001, which specifies the personal protective practices and equipment that must be available for healthcare workers and patients in the United States.
But there are difficulties involved in the use of protective equipment. For example, in an emergency, there may not be time to properly clean protective clothing or to maintain the supply of disposable protective equipment, such as gloves or disposable needles. As a result, protective equipment may be re-used when it should not be, and the contaminated equipment can continue the spread of infection. During the first documented outbreak of Ebola hemorrhagic fever in Zaire in 1976, the virus quickly spread to hospital workers when non-disposable needles were reused and protective barriers, such as non-permeable gowns and face shields, were not available.
As shown in the months following the September 11, 2001, terrorist attacks on the United States, the deliberate airborne release of an infectious organism, such as B. anthracis, can easily occur. A large scale release of such a pathogen could affect a wide geographical area, requiring the rapid deployment of many personnel. It is unlikely that their need for protective equipment could be met from a central source, since even facilities dedicated to the study of highly infectious microbes usually have only a limited number of full-body protective suits on hand. This is an issue that those responsible for emergency planning need to address.
Lawrence, Jean, and Dee May. Infection Control in the Community. New York: Churchill Livingstone, 2003.
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.