By Michael Florman, DDS
Course Objectives: The following course summarizes the Centers for Disease Control and Prevention’s Morbidity and Mortality Weekly Report titled: Guideline for Hand Hygiene in Healthcare Settings. Hand hygiene is one of the most important infection control preventive measures available to reduce the risk of contracting, and/or spreading infectious diseases in the dental office. After completion of this course, the reader will have a better understanding of procedures and products recommended to prevent the spread of disease.
Hand washing with soap and water has been considered a measure of personal hygiene since the early 19th century. In 1822, solutions containing either lime or soda chlorides were used as disinfectants and antiseptics. In 1825, statements were made that physicians and patients with contagious diseases would benefit from moistening their hands with liquid chloride solutions. In 1843, Oliver Wendell Holmes concluded that puerperal fever was spread by the hands of health personnel. Guidelines for hand washing and hand antisepsis were then published in 1988 and 1995 by the Association for Professionals in Infection Control (APIC). Recommended indications for hand washing are similar to those listed in the CDC guidelines. In 1995, the APIC guidelines included more detailed discussion of alcohol-based hand-rubs and supported their use in more clinical settings than had been recommended in earlier guidelines. In 1996 the Healthcare Infection Control Practices Advisory Committee (HIC-PAC) recommended that either antimicrobial soap and/or waterless antiseptic agents be used for cleaning hands upon leaving the rooms of patients with multi-drug resistant pathogens. These guidelines also provided recommendations for hand washing and hand antisepsis and other clinical settings, including routine patient care.
Normal Bacterial Skin Flora
Normal human skin is colonized with millions of bacteria. Total counts on the hands of medical personnel range from 3.9 × 104 to 4.6 × 106. Bacteria on hands are categorized into two groups: transient and resident flora.
Transient flora colonizes the superficial layers of the skin, and can be removed by routine hand washing. Healthcare workers acquire them during direct contact with patients or contact with contaminated surfaces in close proximity to patients. Organisms categorized as transient flora are most frequent with healthcare associated infections. Resident flora is attached to deeper layers of the skin, and is resistant to removal. Resident flora consists of such strains as coagluase-resistant staphylococci and diphtheroids.
Healthcare workers’ hands may become persistently colonized with pathogenic flora such as staphylococcus aureus, gram-negative bacilli, or yeasts. Investigators have documented that the number of transient and resident flora varies considerably from person to person, and is relatively constant.
Physiology of Normal Skin
Skin is the largest organ in the body. Its primary functions are to reduce water loss, provide protection against entry of microorganisms, and act as a permeability barrier to the environment. Skin consists of four layers: 1. Stratum corneum or horn layer (10 to 20µm thick) 2. epidermis (50 to100µm thick) 3. dermis (1 to 2mm thick) 4. hypodermis (1 to 2mm thick).
Plain Soap (Non-Antimicrobial)
Soaps are detergent-based products containing esterified fatty acids and sodium or potassium hydroxide. Their cleaning activity is attributed to their detergent properties, which result in removal of various organic substances (dirt) from the hands. They have no significant antimicrobial activity. Hand washing with plain soap can remove loosely adherent transient flora. Studies have shown that hand washing with plain soap fails to remove pathogens from the hands of hospital personnel. Non-antimicrobial soaps lacking emollients may be associated with skin irritation and dryness. Plain soaps can become contaminated and lead to gram-negative bacilli colonization of hands.
In the U.S., alcohol-based hand antiseptics contain isopropanol or ethanol, or a combination of two. The antimicrobial activity of alcohols can be attributed to their ability to denature proteins. Solutions containing 60%-95% alcohol are most effective. Higher alcohol concentrations are less effective. Alcohol needs to have sufficient water present to kill organisms.
Alcohols have excellent in vitro germicidal activity against gram-positive and gram-negative vegetative bacteria. These include multi-drug resistant pathogens such as Mycobacterium tuberculosis and various fungi. Enveloped lipophilic viruses such as herpes simplex, HIV, influenza, respiratory syncytial virus, and vaccinia virus are susceptible to alcohols when tested in vitro. Hepatitis B virus is an enveloped virus that is somewhat less susceptible, but is killed by 60%-70% alcohol. Hepatitis C virus also is likely killed by this percentage of alcohol. Alcohols have poor activity against certain nonenveloped (nonlipophilic) viruses, bacterial spores, and protozoan cysts.
Alcohols effectively reduce bacterial counts on the hands. Alcohols are rapidly germicidal when applied to the skin, and have no appreciable residual activity. Re-growth of bacteria on the skin occurs slowly after use of alcohol-based hand products, due to the sub-lethal effects alcohols possess on some skin bacteria. The addition of quaternary ammonium compounds such as chlorhexidine, octenidine, or triclosan to alcohol-based solutions can result in persistent activity. When alcohols are used in concentrations present in alcohol-based hand-rubs, they also have in vivo activity against several non-enveloped viruses. Alcohols are not appropriate for use when hands are visibly dirty or contaminated with body fluids. When small amounts of protein material such as blood are present, ethanol and isopropanol may reduce viable bacterial counts on hands more than plain soap or antimicrobial soaps.
Alcohol can prevent the transfer of pathogens amongst healthcare providers. These products are more effective for standard hand washing or hand antisepsis by healthcare workers than soap or antimicrobial soaps. In most of the clinical trials that compared alcohol-based solutions with antimicrobial soaps or detergents, alcohol reduced bacterial counts on hands more than washing hands with soaps or detergents containing hexachlorophene, povidone iodine, 4% chlorhexidine, or triclosan. In studies examining antimicrobial-resistant organisms, alcohol-based products reduced the number of multi-drug resistant pathogens recovered from the hands of healthcare workers more effectively than did hand washing with soap and water. Alcohols are effective for preoperative cleaning of the hands of surgical personnel. Alcohol-based solutions were more effective than washing hands with plain soap in all studies, and they reduced bacterial counts on the hands more than antimicrobial soaps or detergents in the majority of experiments.
The efficacy of alcohol-based hand hygiene products is affected by several factors, including the type of alcohol used, concentration of alcohol, contact time, volume of alcohol used, and whether the hands are wet when the alcohol is applied. If hands feel dry after rubbing hands together for 10-15 seconds, an insufficient amount of product was applied. Alcohol-impregnated towelettes contain a limited amount of alcohol, and therefore are only as effective as using soap and water.
Alcohol-based hand-rubs intended for use in hospitals are available as rinses, foams, and gels. Frequent use of alcohol-containing formulations for hand antisepsis can cause drying of the skin unless emollients, humectants, or other skin-conditioning agents are added. Studies demonstrate that alcohol-based rinses or gels containing emollients caused substantially less skin irritation and dryness than soaps or antimicrobial detergents. Products containing strong fragrances may be poorly tolerated by caregivers and/or patients with respiratory allergies. Allergic contact dermatitis or contact urticaria syndrome can be caused by hypersensitivity to alcohol or to various additives present.
Chlorhexidine gluconate (CG) is a cationic bisbiguanide. The antimicrobial activity is attributable to attachment and disruption of organisms’ cytoplasmic membranes. Antimicrobial activity occurs more slowly than with alcohols. CG has good activity against gram-positive bacteria. It has less activity against gram-negative bacteria and fungi. CG is not sporicidal and has minimal activity against tubercle bacilli. It has in vitro activity against enveloped viruses such as herpes simplex virus, HIV, cytomegalovirus, influenza, and RSV, but substantially less activity against nonenveloped viruses like rotavirus, adenovirus, and enteroviruses. The antimicrobial activity is only minimally affected by the presence of organic material such as blood. CG activity is reduced by the presence of natural soaps, various inorganic anions, non-ionic surfactants, and hand creams containing anionic emulsifying agents. CG has been incorporated into a number of hand hygiene preparations. Aqueous or detergent formulations containing 0.5% or 0.75% are more effective than plain soap, but they are less effective than antiseptic detergent preparations containing 4%. Preparations with 2% are slightly less effective than those containing 4% chlorhexidine. CG has substantial residual activity. The addition of low concentrations (0.5%-1.0%) of CG to alcohol-based preparations results in greater residual activity than alcohol alone. When used as recommended, CG has an above average safety record. Minimum if any absorption of the compound occurs through the skin. Avoid contact with the eyes when using preparations with >1%. The frequency of skin irritation is concentration dependent. Allergic reactions are uncommon. Occasional outbreaks of nosocomial infections have been traced to contaminated solutions of CG.
Chloroxylenol is also known as parachlorometaxylenol (PCMX). This halogen substituted phenolic compound is used as a preservative in cosmetics and other consumer products, and is an active agent in antimicrobial soaps. The antimicrobial activity of PCMX is likely attributable to inactivation of bacterial enzymes and alteration of organism’s cell walls. In vitro activity against gram-positive organisms is good, and activity against gram-negative bacteria, mycobacteria, and certain viruses is fair. The antimicrobial activity of PCMX is minimally affected by the presence of organic matter, and is neutralized by nonionic surfactants. PCMX is absorbed through the skin, and is usually well tolerated. Allergic reactions associated with its use are uncommon. PCMX is available in concentrations of 0.3%-3.75%.
Hexachlorophene is a bisphenol compound. Emulsions containing 3% hexachlorophene were widely used for hand washing and surgical scrubs. The antimicrobial activity of hexachlorophene results from its ability to inactivate essential enzyme systems in microorganisms. Hexachlorophene is bacteriostatic, with good activity against S. aureus and relatively weak activity against gram-negative bacteria, fungi, and mycobacteria. Studies of hexachlorophene as a hygienic hand wash and surgical scrub demonstrated only modest efficacy after a single hand wash. Hexachlorophene has residual activity for several hours after use and gradually reduces bacterial counts on hands after multiple uses. With repeated use of 3% hexachlorophene preparations, the drug is absorbed through the skin. Be certain to rinse thoroughly. It should not be used in pregnant women. Soaps containing 3% hexachlorophene are available by prescription only. Do not use on burned or denuded skin, or to bathe children.
Iodine and Iodophors
Iodine has been recognized as an effective antiseptic since the 1800s, but causes irritation and discoloration of skin. Typical 10% povidone iodine formulations contain 1% available iodine and yield free iodine concentrations of 1ppm. Combining iodine with various polymers increases the solubility of iodine and promotes sustained release of iodine, thus reducing skin irritation. The most common polymers incorporated into iodophors are polyvinyl pyrrolidone (povidone) and ethoxylated nonionic detergents (poloxamers).
The antimicrobial activity of iodophors also can be affected by pH, temperature, exposure time, concentration of total available iodine, and the amount and type of organic and inorganic compounds present, such as alcohols and detergents. Iodine and iodophors have bactericidal activity against gram-positive, gram-negative, and certain spore-forming bacteria (clostridia and Bacillus spp.) They are active against mycobacteria, viruses, and fungi. In concentrations used in antiseptics, iodophors are not usually sporicidal. In vivo studies have demonstrated that iodophors reduce the number of viable organisms. The extent to which iodophors exhibit persistent antimicrobial activity after they have been washed off the skin is unclear. The in vivo antimicrobial activity of iodophors is substantially reduced in the presence of organic substances. Iodophor preparations used for hand hygiene contain 7.5%-10% povidone iodine. Formulations with lower concentrations also have good antimicrobial activity because dilution increases free iodine concentrations. As the amount of free iodine increases, the degree of skin irritation also may increase. Iodophors cause less skin irritation and fewer allergic reactions than iodine, but more irritant contact dermatitis than other antiseptics commonly used for hand hygiene.
Quaternary Ammonium Compounds
Alkyl benzalkonium chlorides are the most widely used as antiseptics. Others have also been used as antiseptics, including benzethonium chloride, cetrimide, and cetylpyridium chloride. The antimicrobial activity of this group of compounds is likely attributable to adherence to the cytoplasmic membrane of cells, which leads to subsequent leakage of low molecular weight cytoplasmic constituents. Quaternary ammonium compounds are primarily bacteriostatic and fungistatic. They are microbicidal against some organisms at high concentrations. They are more active against gram-positive bacteria than against gram-negative bacilli. They have relatively weak activity against mycobacteria and fungi but exhibit some activity against lipophilic viruses. Their ability to kill is adversely affected by the presence of organic materials. They do not work well with anionic detergents. They are well tolerated.
Triclosan has been added to soaps, toothpastes, and other consumer products. Concentrations of 0.2%-2.0% have antimicrobial activity. Triclosan enters bacteria and affects the cytoplasmic membrane and synthesis of RNA, fatty acids, and some proteins. Its antibacterial activity is attributable to binding to the active site of enoylacyl carrier protein reductase. Triclosan has a broad range of antimicrobial activity, but it is often bacteriostatic. Its activity against gram-positive organisms is greater than against gram-negative bacilli, particularly P. aeruginosa. The agent possesses reasonable activity against mycobacteria and Candida spp, but it has limited activity against filamentous fungi. Formulas containing 0.1% reduce bacterial counts on hands by 2.8 log10 after one minute of hand washing. Bacterial reductions are lower when using triclosan as compared to chlorhexidine, iodophors, or alcohol-based products. Triclosan is nonionic. Like chlorhexidine, triclosan has persistent activity on the skin. Its activity in hand-care products is affected by pH, the presence of surfactants, emollients, humectants and by the ionic nature of the particular formulation. Triclosan’s activity is not substantially affected by organic matter. Formulations containing <2% triclosan are well tolerated. Allergic reactions are also rare.
Activity of Antiseptic Agents Against Spore-Forming Bacteria
The prevalence of healthcare associated diarrhea caused by Clostridium difficile and the recent events associated with the spread of biological terrorism agents such as Bacillus anthracis has increased. None of the agents (including alcohols, chlorhexidine, hexachlorophene, iodophors, PCMX, or triclosan) used in antiseptic hand wash or antiseptic preparations are reliably sporicidal against Clostridium spp. and Bacillus spp. Washing hands with non-antimicrobial or antimicrobial soap and water may help to remove spores from the surface of contaminated hands.
Allergic Contact Dermatitis Associated with Hand Hygiene Products
Allergic reactions to products applied to the skin may present as delayed type reactions called contact dermatitis. Less common reactions are immediate, and called contact urticaria. The most common causes of contact allergies are fragrances and preservatives. Emulsifiers are third on the list of common causes. Liquid soaps, hand lotions or creams, may contain ingredients that cause contact allergies. If irritations or changes in skin color occur, you should stop using the product and seek a dermatological consultation.
Fingernails and Artificial Nails
Studies have documented that subungual areas of the hand harbor high concentrations of organisms. Most frequently found are coagulase-negative staphylococci, gram-negative rods, including Pseudomonas spp, Corynebacteria, and yeasts. Freshly applied nail polish does not increase the number of bacteria recovered from periungual skin, but chipped nail polish may support the growth of larger numbers of organisms on finger nails. Substantial numbers of potential pathogens in the subungual spaces still exist even after following surgical hand washing procedures. It is unknown if artificial nails contribute to transmission of healthcare associated infections. Healthcare workers who wear artificial nails are more likely to harbor gram-negative pathogens on their fingertips than are those who have natural nails, both before and after hand washing. The majority of bacterial growth occurs along the proximal 1 mm of the nail adjacent to subungual skin. Hospital outbreaks have been reported and have been linked to nurses with long artificial nails.
CDC recommends that healthcare workers wear gloves to: reduce the risk of personnel acquiring infections from patients, prevent healthcare workers flora from being transmitted to patients, and to reduce transient contamination of the hands of personnel by flora that can be transmitted from one patient to another. The OSHA mandate states that gloves must be worn during all patient-care activities that may involve exposure to blood or body fluids that may be contaminated with blood. The effectiveness of gloves in preventing contamination of healthcare workers’ hands has been confirmed in several clinical studies.
Practitioners need to be informed that gloves do not provide complete protection against hand contamination. Bacterial flora colonizing patients may be recovered from the hands of <30% of healthcare workers who wear gloves during patient contact.
Further, wearing gloves does not provide complete protection against acquisition of infections caused by hepatitis B virus and herpes simplex virus. Pathogens presumably gain access to the practitioner’s hands via small defects in gloves or by contamination of the hands during glove removal. Gloves are made of natural rubber latex or synthetic non latex materials (vinyl, nitrile, and neoprene). Because of the increasing prevalence of latex sensitivity among practitioners and patients, the FDA has approved several powdered and powder free latex gloves with reduced protein contents, as well as synthetic gloves for use by latex-sensitive people. In published studies, the barrier integrity of gloves varies on the basis of type and quality of glove material, intensity of use, length of time used, and manufacturer testing for glove leaks. Studies show that vinyl gloves have defects more frequently than latex gloves. Defect frequency is greatest after glove use, however, intact vinyl gloves provide protection comparable to that of latex. Limited studies indicate that nitrile gloves have leakage rates that approximate those of latex gloves. Hands should be decontaminated or washed after removing gloves. Gloves should not be washed or reused. Use of petroleum-based hand lotions or creams may adversely affect the integrity of latex gloves. After use of powdered gloves, certain alcohol-based hand-rubs may interact with residual powder resulting in a gritty feeling on the hands. In facilities where powdered gloves are commonly used, various alcohol-based hand-rubs should be tested after removal of powdered gloves to avoid selecting a product that causes this undesirable reaction. Personnel should be reminded that failure to remove gloves between patients may contribute to transmission of organisms.
Studies have demonstrated that skin underneath rings is more heavily colonized than comparable areas of skin on fingers without rings. Further studies are needed to establish if wearing rings results in greater transmission of pathogens in healthcare settings.
Recommendations For Practitioners
1. Indications for hand washing and hand antisepsis include the following:
- When hands are visibly soiled, wash them with either a non-antimicrobial soap and water or an antimicrobial soap and water.
- If hands are not visibly soiled, use an alcohol-based hand-rub. Alternatively, wash hands with an antimicrobial soap and water in all clinical situations.
- Decontaminate hands before having direct contact with patients.
- Decontaminate hands after contact with a patient’s intact skin (e.g., when taking a pulse or blood pressure, or lifting a patient).
- Decontaminate hands after contact with body fluids or excretions, mucous membranes, non-intact skin, and wound dressings if hands are not visibly soiled.
- Decontaminate hands if moving from a contaminated-body site to a clean-body site during patient care.
- Decontaminate hands after contact with inanimate objects (including medical equipment) in the immediate vicinity of the patient.
- Decontaminate hands after removing gloves.
- Prior to eating and after using a restroom, wash hands with a non-antimicrobial soap and water or with an antimicrobial soap and water.
- Antimicrobial-impregnated wipes (towelettes) may be considered as an alternative to washing hands with non-antimicrobial soap and water. They are not as effective as alcohol-based hand-rubs or washing hands with an antimicrobial soap and water for reducing bacterial counts on the hands. They are not a substitute for using an alcohol-based hand-rub or antimicrobial soap.
- Wash hands with non-antimicrobial soap and water or with antimicrobial soap and water if exposure to Bacillus anthracis is suspected or proven. The physical action of washing and rinsing hands under such circumstances is recommended because alcohols, chlorhexidine, iodophors, and other antiseptic agents have poor activity against spores. No recommendation can be made regarding the routine use of non-alcohol-based hand-rubs for hand hygiene in healthcare settings.
2. Hand hygiene technique
- When decontaminating hands with an alcohol-based hand-rub, apply product to palm of one hand and rub hands together, covering all surfaces of hands and fingers until hands are dry. Follow the manufacturer’s recommendations regarding the volume of product to use.
- When washing hands with soap and water, wet hands first with water, apply an amount of product recommended by the manufacturer to hands, and rub hands together vigorously for at least 15 seconds, covering all surfaces of the hands and fingers. Rinse hands with water and dry thoroughly with a disposable towel. Use towel to turn off the faucet. Repeated exposure to hot water may increase the risk of dermatitis.
- Liquid, bar, leaflet or powdered forms of plain soap are acceptable when washing hands with a non-antimicrobial soap and water. When bar soap is used, soap racks that facilitate drainage and small bars of soap should be used.
- Multiple-use cloth towels of the hanging or roll type are not recommended for use in healthcare settings.
3. Surgical hand antisepsis
- Remove rings, watches, and bracelets before beginning the surgical hand scrub.
- Remove debris from underneath finger nails using a nail cleaner under running water.
- Surgical hand antisepsis using either an antimicrobial soap or an alcohol-based hand-rub with persistent activity is recommended before donning sterile gloves.
- When performing surgical hand antisepsis using an antimicrobial soap, scrub hands and forearms for the length of time recommended by the manufacturer, usually 2-6 minutes. Long scrub times (10 minutes) are not necessary.
- When using an alcohol-based surgical hand-scrub product with persistent activity, follow the manufacturer’s instructions. Before applying alcohol solutions, pre-wash hands and forearms with a non-antimicrobial soap. Dry hands and forearms completely. After application of the alcohol-based product as recommended, allow hands and forearms to dry thoroughly before donning sterile gloves.
4. Selection of hand hygiene agents
- Provide personnel with efficacious hand hygiene products that have low irritancy potential, particularly when these products are used several times per shift. This recommendation applies to products used for hand antisepsis before and after patient care in clinical areas, and to products used for surgical hand antisepsis by surgical personnel.
- To maximize acceptance of hand hygiene products, solicit input from employees regarding the feel, fragrance, and skin tolerance of any products under consideration. The cost of hand hygiene products should not be the primary factor influencing product selection.
- When selecting non-antimicrobial soaps, antimicrobial soaps, or alcohol-based hand-rubs, solicit information from manufacturers regarding any known interactions between products used to clean hands, skin care products, and the types of gloves used in the institution.
- Before making purchasing decisions, evaluate the dispenser systems of various product manufacturers or distributors to ensure that dispensers function adequately and deliver an appropriate volume of product.
- Do not add soap to a partially empty soap dispenser. This practice of topping-off dispensers can lead to bacterial contamination of soap.
5. Skin care
- Use hand lotions or creams to minimize the occurrence of irritant contact dermatitis associated with hand antisepsis or hand washing.
- Solicit information from manufacturers regarding any effects that hand lotions, creams, or alcohol-based hand antiseptics may have on the persistent effects of antimicrobial soaps being used in the institution.
6. Other aspects of hand hygiene
- Do not wear artificial fingernails or extenders when having direct contact with patients at high risk, such as those patients in intensive-care units or operating rooms.
- Keep natural nail tips less than 1/4 inch long.
- Wear gloves when contact with blood or other potentially infectious materials, mucous membranes, and non-intact skin could occur.
- Remove gloves after caring for a patient. Do not wear the same pair of gloves for the care of more than one patient and do not wash gloves between different patients and re-use.
- Change gloves during patient care if moving from a contaminated body site to a clean body site.
- No recommendation can be made regarding wearing rings in healthcare settings. It is an unresolved issue.
7. Healthcare worker educational and motivational programs
- As part of an overall program to improve hand hygiene practices, educate personnel regarding the types of patient care activities that can result in hand contamination and the advantages and disadvantages of various methods used to clean their hands.
- Monitor adherence with recommended hand hygiene practices and provide personnel with information regarding their performance.
- Encourage patients and their families to remind healthcare workers to decontaminate their hands.
8. Administrative measures
- Make improved hand hygiene adherence an institutional priority and provide appropriate administrative support and financial resources.
- Implement a multidisciplinary program designed to improve adherence of health personnel to recommended hand hygiene practices.
- As part of a multidisciplinary program to improve hand hygiene adherence, provide healthcare workers with a readily accessible alcohol-based hand-rub product.
- To improve hand hygiene adherence among personnel who work in areas in which high workloads and high intensity of patient care are anticipated, make an alcohol-based hand-rub available at the entrance to the patients room or at the bedside, in other convenient locations, and in individual pocket-sized containers to be carried by healthcare workers.
- Store supplies of alcohol-based hand-rubs in cabinets or areas approved for flammable materials.
Michael Florman, DDS received his dental degree from the Ohio State University and completed his post graduate training in Orthodontics at New York University. Dr. Florman is a Diplomate of the American Board of Orthodontics, and has been practicing dentistry since 1991. He is highly respected as both an orthodontist and an educator. He has authored over forty scientific publications in the field of dentistry and medicine. Dr. Florman is the Executive Program Director for the Academy of Dental Therapeutics and Stomatology, a national dental continuing education organization. He is also an active clinical advisor to many pharmaceutical and dental companies. He is a member of the American Dental Association, California Dental Association, and the American Association of Orthodontists.
The author of this course has no commercial ties with the sponsors or the providers of the unrestricted educational grant for this course.
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