PART 1 OF 3
The goal of Part 1 is to present modes of disease transmission and effective strategies for prevention and to inform clinicians that failure to adhere to standards could lead to disciplinary action.
Part 1 in this series focuses on the first two of six elements that make up this required course work. These elements are: 1) professional responsibility; 2) modes and mechanisms of transmission of pathogenic organisms; 3) engineering and work practice controls; 4) selection and use of barriers or personal protective equipment; 5) infection control principles and practices for cleaning, disinfection and sterilization; and 6) prevention and control of infectious and communicable diseases in healthcare workers.
The Buck Stops Here
Let’s say you work in a clinic. A patient calls with complaints of a rash. She mentions that her nephew had chickenpox two weeks ago. She arrives an hour later and makes herself comfortable in the waiting room with other patients. Are you guilty of “Failure to anticipate a potentially infectious condition and take appropriate action?” Now, put yourself in the hospital setting. You take report on an ED transfer who has had night sweats and a cough. You walk into his room without a respirator mask. Is it just “oops” or are you guilty of the same infraction? Consider a home care worker, who spills a urine specimen and wipes it up with a paper towel. Is this unprofessional conduct? According to the law, it certainly is.
As you can see, the potential for transmission of pathogens is present regardless of where healthcare is delivered. Each of these examples was potentially avoidable had the clinicians anticipated the possibility of a diagnosis, identified potential infectious conditions and chosen appropriate barrier devices, and used the safest work practices possible to protect themselves and their patients from infection. Some state health codes now place responsibility on the healthcare professional to recognize the possibility of the spread of communicable disease and to take measures to prevent such spread.
For example, to ensure public safety, many states have passed legislation that requires nurses and other licensed healthcare workers to complete course work in infection control and barrier precautions. The intent of this legislation is to promote use of safe work practices and engineering controls to reduce the opportunity for patient and employee exposure.
In addition to this continuing education, healthcare professionals are responsible for monitoring the performance of all personnel, licensed or not, under their supervision regarding infection control techniques. Failure to adhere to these principles is considered unprofessional conduct and could subject the nurse or other healthcare professional to disciplinary action, revocation of license or professional liability.
Not only are there professional consequences, but failure to adhere to infection control standards also puts you and your patients at risk for adverse health outcomes. Read on to learn how to avoid these dire hazards.
A Chain of Events
An infectious disease cannot spread from one person to another unless there is an intact chain of transmission that includes the infectious agent, a reservoir, an exit from the reservoir, an environment conducive to transmission of the infectious agent, an entry into a new host and a susceptible new host. You can prevent the spread of disease by breaking any link in the chain.1 (Level ML)
A chain of infection begins with the pathogen or infectious agent. Bacteria, such as Staphylococcus aureus; viruses, including herpes simplex; fungi, including Candida albicans; and parasites, such as Cryptosporidium are all potential culprits. The reservoir — or source of the infectious agent — is any person, animal, plant or substance in which an infectious agent normally lives and multiplies. A reservoir can be inanimate. For example, Salmonella, a common cause of food poisoning, is found in improperly prepared egg products or poultry. In this case, the processed food is considered the inanimate reservoir.
A “common vehicle” is the term used to describe contaminated material that serves as a means by which an infectious agent can be transported. Take, for example, outdated, multidose containers of medication or diluent. These vials can get contaminated and become a breeding ground. Also, be wary that a person may actually be a carrier of an infectious agent and pass it along unknowingly.
Next in the chain of events comes the portals of exit — sneezing, draining lesions and blood and body fluids are all means by which a pathogen escapes. To infect another person, however, there must be a portal of entry, which includes:
- GI tract
- Genitourinary (GU) system
- Respiratory tract
- Mucous membranes
- Percutaneous injuries
- Invasive procedures
- Vascular access
Pathogens can be transmitted by direct or indirect contact. Agents can be spread by droplet and become airborne, as in the case of TB or measles. Transmission can even occur with the help of a vector.1 (Level ML)
Such is the case when mosquitoes transmit malaria to humans. And last, the chain is complete when there is a susceptible host — a person lacking the resistance to the offending agent.
Improving the Odds
Factors intrinsic to the susceptible host influence the outcome of exposure to pathogens. Advanced age at one end of the spectrum and prematurity at the other end can affect the competence of organ systems to resist infection. Chronic diseases also impair host defenses.
The Joint Commission, which devotes an entire chapter in its Accreditation Manual for Hospitals to infection control, also expects hospitals to identify infection control risks based upon characteristics of the population served. The Center for Medicare and Medicaid Services echoes high expectations for infection prevention and control.2
A number of natural barriers serve to protect the body from invasion by microorganisms. Intact skin, tears, cough and gag reflexes, respiratory cilia and gastric acidity function as impediments to the influx of bacteria that would colonize or invade deeper tissues. Anesthesia, intubation, surgery and medication often inhibit — at least briefly — these functions.
Once tissues have been infected, the inflammatory response and humoral and cell-mediated immunities are activated. Conditions such as renal failure, diabetes and lymphocytic leukemia, as well as medical treatments (e.g., use of steroids, chemotherapy) can impair or suppress these functions.
Virulence of the microorganism can contribute to the morbidity of the susceptible host. Pathogens may secrete exotoxins that have a local or systemic impact. Strains of Pseudomonas that secrete an exotoxin can cause a rapidly progressive necrotizing pneumonia, while certain strains of Staphylococcus secrete a toxin responsible for toxic shock.
The size of inoculum (microorganisms or infectious material) may dictate whether infection occurs. Although a small number of influenza virions or tuberculosis bacilli are sufficient to produce disease in the susceptible host, often a large inoculum is more likely than a small one to produce illness. A classic example is Salmonella, which is unlikely to produce infection when ingested by a healthy host unless many thousands of organisms are present. Similarly, a small inoculum of blood on mucous membranes or broken skin is less likely to result in transmission of an organism like HIV than is a large inoculum. The duration of contact between pathogenic organism and its portal of entry also correlates with the likelihood of subsequent infection. For this reason, contaminated skin and mucous membranes should be promptly washed free of inoculum.
The route of exposure can make a difference in the likelihood of infection or the nature of that infection, depending on the pathogen. Deposition of Klebsiella in a surgical wound could result in a wound infection, although ingestion of large numbers of the same organism would not be expected to produce disease. Ingestion of Staphylococcus that had multiplied in improperly stored potato salad might result in gastroenteritis, while growth of the same pathogen in nasal packing could result in toxic shock syndrome.
The Weakest Link
A chain is only as strong as its weakest link. With that in mind, winning the battle means breaking a link in the chain of transmission. Here are some ways you can dismantle the sequence. Begin by controlling reservoirs.
- Recognize potential reservoirs to minimize later problems. Take, for instance, a unit clerk who has never had varicella. If she develops a febrile illness as her friends’ children are recovering from chickenpox, encourage her to stay home until the nature of her illness becomes clear.
- Eliminate pathogenic hazards in the clinical setting. Throw away outdated containers of skin cleansers, disinfectants and diluents. These may have become contaminated and represent a potential risk to patients and healthcare workers using them.
- Control the route of transmission by becoming familiar with how and when common communicable illnesses present clinically. Keep your index of suspicion keen, and rely on diagnostic measures to determine whether additional steps such as isolation or therapeutic intervention are required.
- Be wary about the environment. Dirty storage areas may contaminate supplies, and infectious secretions can contaminate surroundings. Remember that some pathogens survive in dried secretions long enough to infect others coming into contact with them. Carpets might be appropriate in adult waiting and consultative areas where soiling with secretions is improbable. A pediatric waiting area, on the other hand, deserves a more impermeable surface that can be sanitized more effectively. While bookshelves in the secretarial area should be dusted regularly, shelves with patient care materials should be enclosed and regularly cleaned with appropriate detergents.
Next, consider strategies that will interrupt the route of transmission. Generally, this takes the consistent use of simple procedures. Handwashing before and after patient contact is essential. Appropriate use of barriers can minimize the risk of contamination as well.1 (Level ML)
The level of sterilization or disinfection of patient care equipment is generally determined by whether the device comes into contact with intact skin, mucous membranes or sterile body areas. However, proper management of the patient-care environment is trickier and depends on the clinician’s ability to anticipate potential pitfalls. Consider the case of a patient on the medical unit with a positive blood culture. The astute clinician performs a prompt initial evaluation, and patient triage will lead to rational patient flow, isolation precautions or cohorting when necessary. In some situations, transfer of patients is necessary.
When it comes to the environment, clinicians may have to direct other departments, including housekeeping and engineering, to be sure windows, air conditioners and air vents are cleaned on a regular basis. Waste management is vital as well. Just as appropriate patient flow is important, the flow of used, potentially contaminated materials and equipment is paramount. Disposable sharp instruments must be placed in puncture-resistant, point-of-use containers. Disposable materials that have been in contact with patients, but which aren’t visibly contaminated with blood or body substances, should be placed in a covered container lined with an impermeable plastic bag. Visibly soiled material must be discarded in containers dedicated for regulated medical waste and later disposed of in the approved fashion.
Contaminated reusable equipment must be taken to a “dirty” utility area to be washed and disinfected or sterilized. Instruments, especially those contaminated with blood or body substances, should be transported from the point of use to the dirty utility area in a covered container. Clean instruments, equipment, linens and disposable supplies must not be stored in the dirty utility area, and personnel leaving the dirty utility area must wash their hands. Handwashing must be done in sinks separate and distinct from the sinks used in the reprocessing of contaminated equipment. Dirty linen should always be held away from your uniform so that it doesn’t contaminate your clothing. Linen/laundry bins must be easily accessible.
Because transmission can only take place when the host is susceptible, vaccination and pre- and postexposure prophylaxis are imperative. Patients or healthcare workers can be made nonsusceptible to certain communicable diseases through immunization. Immunity to rubella and rubeola is recommended and sometimes required of healthcare workers. Immunization to hepatitis B is strongly recommended, especially for those having regular exposure to blood and tissue. Postexposure prophylaxis should take place immediately should a needlestick occur.
The Big Picture
All of the aforementioned infection reduction mechanisms, controlling reservoirs, handwashing, isolation techniques, etc., should be part of a hospital’s organization-wide infection control program. Each Joint Commission-accredited hospital is expected to have an effective infection control program in place that will minimize healthcare-associated infections. The Joint Commission’s standards, which hospitals are required to comply with, include:3
- Identification of individual(s) responsible for the infection prevention and control program. This individual or group of individuals has clinical authority over the program, and must have expertise in infection prevention and control or the ability to consult with an expert as needed for decision making. Responsibilities include the development and implementation of policies governing the control of infections and communicable diseases in addition to developing a system for identifying, reporting, investigating and controlling infections and communicable disease.
- Allocation of resources for the infection prevention and control program. This is an important part of the development of the plan and its management. Resources include qualified infection prevention staff and other key team members, information, laboratory services, equipment and supplies.
- Identification of risks for acquiring and transmitting infections. This is a team effort and includes infection prevention staff, medical staff, nursing and leadership in addition to community leaders as appropriate. This identification of risks for acquiring and transmitting infections should be based on geographic location, community and population served as well as the care, treatment and services provided. Additional risks are identified through the analysis of surveillance activities and other infection control data. These risks are reviewed annually and as significant changes occur.
- Development of goals to minimize the possibility of transmitting infections based on the identified risks. The identified risks should be prioritized based on level of probability and potential for harm. The goals address these risks and should include limiting unprotected exposure to pathogens; limiting the transmission of infections associated with procedures; limiting the transmission of infections associated with the use of medical equipment, devices and supplies; and improving compliance with hand hygiene guidelines. The goals should then result in activities based on relevant professional guidelines and sound scientific processes.
- Development of an infection prevention and control plan. This is a written document that includes a written description of the activities to minimize, reduce or eliminate the risks of infection. The plan includes all hospital functions and components, and activities are developed using evidence-based national guidelines or expert consensus when guidelines are absent. The infection prevention and control plan also includes the process for outbreak investigation and methods to communicate infection surveillance and control information to appropriate external organizations. Communication methods are also addressed and include licensed independent practitioners, staff, visitors, patients and families.
- Preparation for an influx of potentially infectious patients. A written response plan is required, describing how the facility will respond to an influx of potentially infectious patients as well as methods to manage these patients over time. An important component of this process is the identification of resources, which may include local, state and federal public health systems. Although specifics on the exact infectious agent may be unknown, current clinical and epidemiological information can aid in planning efforts and information about potential emerging infections needs to be shared with licensed independent practitioners.
- Implementation of the infection prevention and control plan. Activities must be practical, collaborative and inclusive of everyone who works in the hospital. The use of standard and transmission-based precautions is required. Information should be available to staff as well as to patients and their families. This includes communication of responsibilities for preventing and controlling infection to licensed independent practitioners, staff, visitors, patients and families including hand and respiratory hygiene. A variety of types of media may be used. Infection prevention, surveillance and control information are also communicated to local, state and federal authorities in accordance with law and regulation. Inter-facility communication throughout the continuum of care regarding infectious patients is expected as well. The plan should also include outbreak investigation and methods to safely store and dispose of infectious waste.
- Reduction of the risk of infections associated with medical equipment, devices and supplies. This includes everything from cleaning and low-level disinfection to high-level disinfection and sterilization. Processing medical equipment requires competency and attention to the details and steps outlined by the manufacturer. Attention also needs to be focused on the disposal or storage of medical equipment, devices and supplies as appropriate.
- Prevention of transmission of infectious disease among patients, licensed independent practitioners and staff. This includes screening for exposure and/or immunity to infectious disease and the referral for assessment and potential testing, prophylaxis/treatment or counseling in the event that contact is anticipated or has occurred.
- Establishment of an annual influenza vaccination program to offer the vaccine to licensed independent practitioners and staff. An essential part of this program is education about the vaccine, nonvaccine control and prevention measures, and the diagnosis, transmission and affect of influenza. Reasons for declining vaccination should be reviewed at least annually. An incremental goal for vaccination should be set each year with the goal of achieving 90% by 2020 as recommended by the U.S. Department of Health and Human Services. Vaccination should be offered at convenient times and locations, and stakeholders should be kept apprised of vaccination rates.
- Evaluation of the effectiveness of the infection prevention and control plan. The findings should be communicated at least annually and used when revising the plan. Evaluation includes a review of the infection prevention and control plan’s prioritized risks and goals and implementation of the plan’s activities.
The Joint Commission expects hospitals to reduce the risk of hospital-acquired infections. Compliance with The Joint Commission’s standards, the Centers for Disease Control and Prevention (CDC) recommendations and the implementation of suggestions made throughout this module will help achieve this goal.
Put the Lid on Transmission
The saying, “An ounce of prevention is worth a pound of cure,” deserves amplification when it comes to infection control. Hand hygiene and isolation precaution strategies are mainstays in preventing cross-infection and protecting both patients and healthcare workers and it’s the single most important precaution for preventing the spread of infection.
In 2002, the CDC issued guidelines
for hand hygiene in healthcare settings.4 (Level ML)
These guidelines were developed to improve hand-hygiene practices and reduce transmission of pathogenic microorganisms to patients and healthcare personnel.4 (Level ML)
A summary of the routine hand hygiene and hand-antisepsis practices recommended by the CDC is provided below. Surgical hand antisepsis related to operative procedures is not included but is discussed in the guidelines.
Hand decontamination using an alcohol-based hand rub is recommended:4
- If hands are not visibly soiled
- Before having direct contact with patients
- Before donning sterile gloves for the purpose of inserting an invasive device that doesn’t require a surgical procedure, such as inserting a central or peripheral intravascular catheter or indwelling urinary catheter
- After contact with a patient’s intact skin, such as following pulse check
- After contact with body fluids, excretions, mucous membranes, nonintact skin and wound dressings if hands are not visibly soiled
- If moving from a contaminated body site to a clean body site during patient care
- After contact with an inanimate object such as medical equipment that’s near the patient
Handwashing with either a nonantimicrobial or antimicrobial soap is recommended:4
- When hands are visibly dirty or contaminated with proteinaceous material or blood
- Before eating and after using the restroom
- If there is suspected or proven exposure to Bacillus anthracis or other spore-forming agents, such as Clostridium difficile
Antimicrobial impregnated wipes, such as towelettes, may be an alternative to handwashing with a nonantimicrobial soap; however, they are not a substitute for alcohol-based rubs or handwashing with an antimicrobial soap. There’s strong evidence that jewelry such as rings and artificial nails harbor bacteria and fungi, but whether they cause a greater transmission of pathogens or contribute to healthcare-associated infections is unknown and an area for further research.4 (Level ML)
Effective handwashing technique requires vigorous rubbing of all surfaces of the hands and fingers against each other with water and a cleanser for a period of 15 seconds, followed by thorough rinsing and drying with a disposable towel. Hot water should be avoided, because it increases the risk for dermatitis, which facilitates pathogen invasion, and multiple-cloth towels for hand drying aren’t recommended for use in a healthcare setting. Liquid, bar, leaflet or powdered forms of soap are acceptable for handwashing with a nonantimicrobial soap and water. However, bar soap is susceptible to harboring bacteria. If it’s used, the bar should be small and a soap rack used to facilitate drainage and drying.4
To effectively decontaminate hands with an alcohol-based rub
, it’s recommended that personnel apply the product to the palm of one hand and rub hands together, covering all surfaces of the hands and fingers until the hands are dry.
Products for hand hygiene should be placed in convenient areas for users and be appropriately gentle to the skin. Products that are irritating or too far from the area they are needed are less likely to be used consistently. It is advisable to have facility-approved hand lotions available to promote healthy skin for staff as well. Keep in mind that scented lotions may exacerbate respiratory symptoms for those who are sensitive to them, and some lotions are not compatible with the hand hygiene products and gloves used in healthcare settings. Lotions should be dispensed from pumps or bottle rather than jars that require the healthcare worker to scoop out the product with their hands. Artificial nails, gels and overlays should not be worn. Some facilities allow short nails with fresh, unchipped nail polish.
Handwashing is such an important part of controlling infections in hospitals that The Joint Commission has made it one of its National Patient Safety Goals. During their visits to patient units, surveyors observe staff members entering and leaving patients’ rooms and note if they washed their hands. If the surveyors determine that there is an unacceptable level of compliance, a formal requirement for improvement is cited and the hospital will be required to develop an action plan to correct the deficiency.
Isolating the Problem
Isolation precautions refer to the procedures used in dealing with all patients to prevent inadvertent transmission of microorganisms from patient to caregiver, caregiver to patient and patient to patient. Current guidelines provide for two tiers of precautions. The first is called Standard Precautions and is the primary strategy for nosocomial infection prevention. The second tier is called Transmission-based Precautions and is an approach directed at interrupting transmission of epidemiologically important pathogens when a specific infective entity is suspected or identified and where additional precautions beyond Standard Precautions are needed.1 (Level ML)
Standard Precautions are an example of an interactive approach that’s applied routinely to all patients. Nothing has to be known about the source patient because the same measures of barrier protection to prevent soiling of skin and mucous membranes are applied equally to all. Barriers appropriate to the activity, such as gloves, protective eye wear and impermeable gowns, should be used to prevent any and all contact between skin and mucous membranes and blood/bodily fluids. Standard Precautions combine the principles of Universal and Body Substance Precautions. Generally, contact with tears and sweat does not require barrier protection.
Transmission-Based Precautions are designed for patients documented or suspected to be infected or colonized with highly transmissible or epidemiologically important pathogens for which additional precautions beyond Standard Precautions are needed. There are three types of Transmission-based Precautions:
Airborne precautions are implemented where highly contagious pathogens may be present and can be spread by airborne droplet nuclei that remain suspended in, and can be widely dispersed by, air currents over considerable distances. These particles remain infective over time and distance and can be inhaled by people who have not even been in the same room with the infected person. The most common agents this applies to are Mycobacterium tuberculosis, which causes tuberculosis; the rubeola virus, which causes measles; and varicella-zoster virus, which causes chickenpox. Patients who have one of these pathogens or are suspected of having one of these pathogens should be placed in a monitored negative pressure room that provides six to 12 air changes per hour. These airborne isolation rooms safely contain and remove the infectious particles. Healthcare personnel are to wear respiratory protection with a NIOSH-certified N95 or higher level of respirator for entering the room. In the case of measles or chickenpox, susceptible people should not enter the room if other immune caregivers are available and must use respiratory protection if entry is unavoidable. The patient, if required to be out of the airborne isolation room for testing, should wear a plain surgical mask to contain any respiratory secretions.1
Droplet precautions are implemented where pathogens are transmitted by infectious droplets. These can be generated by coughing, sneezing and talking or during procedures such as suctioning, endotracheal intubation, cough induction, chest physiotherapy and cardiopulmonary resuscitation. The pathogen can be transmitted directly from the respiratory tract of the infected person to a susceptible mucosal surface of the recipient or indirectly through contact with an object contaminated in the environment. Unlike infections spread by the airborne route, infections spread through droplets are believed to travel a distance of three feet or less. Segregation from others is desirable but less critical than with airborne precautions. Masks are necessary when working within three to six feet of the patient. Special ventilation is not necessary. Infections spread through the droplet route include Bordetella pertussis, influenza virus, adenovirus, rhinovirus, Mycoplasma pneumoniae, SARS-associated coronavirus (SARS-CoV), group A streptococcus and Neisseria meningitidis.1
Contact precautions are implemented for patients known or thought to be infected or colonized with epidemiologically important microorganisms that can be transmitted by direct or indirect contact. Examples include methicillin-resistant Staphylococcus aureus (MRSA), scabies and Clostridium difficile. Wear gloves for contact with patients and immediate surroundings (gloves don’t have to be sterile unless a specific procedure requires sterility). As clothing can also be contaminated by contact with the patient or items in the patient’s environment, an isolation gown should be worn as well.1 Gloves are always discarded as the wearer leaves the patient environment, and hands need to be washed immediately. Similarly, gowns should be discarded in appropriate receptacles.
There are certain instances where more than one type of transmission-based precaution may be needed. For example, the patient with disseminated shingles should be placed in airborne precautions and contact precautions to prevent the spread to other individuals. Another example is the person who has seasonal influenza as well as a skin infection with MRSA. That patient would need droplet precautions for the influenza and contact precautions for the MRSA. The CDC provides detailed recommendations for the type of precautions to use based on the infection or condition, but it is essential to follow standard precautions with every patient every time.1