REVIEW OF LITERATURE
The following keywords were used as the topic thrust for the review:
* Standard precautions
* Knowledge of standard precautions
* Practice of standard precautions
2.1 Standard Precautions
2.1.1 Historical Background
The CDC first published a document in 1983 entitled ‘Guidelines for Isolation Precautions in Hospital’, which contained a section on precautions for blood and body fluids. The section recommended preventive measures to be taken when a patient is known or suspected to be infected with blood-borne pathogens (Garner, Simmons & Williams 1983: A8-8). In 1987, CDC published ‘Recommendations for Prevention of HIV Transmission in Healthcare Settings’. In contrast to the 1983 guidelines, the Recommendations suggested that precautions be consistently used for all patients regardless of their blood-borne infection status. This extension became known as the Universal Precautions and it was defined by CDC (1996) as a set of precautions designed to prevent the transmission of HIV, HBV and other blood-borne pathogens when providing first aid or health care. Under the universal precautions, blood and certain body fluids of all patients were considered potentially infectious for HIV, HBV and other blood-borne pathogens. Thus, universal precautions replaced and eliminated the need for the isolation category "blood and body fluid precautions" in the 1983 CDC Guidelines for Isolation Precautions in Hospitals.
Universal precautions was applicable to blood, other body fluids containing visible blood, semen, vaginal secretions, tissues, and the cerebrospinal, synovial, pleural, peritoneal, pericardial, and amniotic fluids. However, the universal precautions did not apply to feaces, nasal secretions, sputum, sweat, tears, urine, and vomitus unless they contained visible blood. It did not also apply to saliva except when visibly contaminated with blood or in the dental setting where blood contamination of saliva is predictable (CDC 1996). Universal precautions recommended the use of protective barriers such as gloves, gowns, aprons, masks, or protective eyewear, which can reduce the risk of exposure of the health care worker's skin or mucous membranes to potentially infective materials. It recommended that all health care workers take precautions to prevent injuries caused by needles, scalpels, and other sharp instruments or devices.
However, additional precautions were needed for diseases transmitted by air and droplet contacts in order to protect health care workers from occupationally acquired pulmonary tuberculosis, severe acute respiratory syndrome (SARS), and, recently, human influenza. These additional precautions included airborne, droplets and contact precautions.
Airborne precautions would reduce the transmission of diseases spread by air. Airborne transmission occurs when droplet nuclei less than 5 micron in size are disseminated in the air for long periods. Diseases spread by this mode include active pulmonary tuberculosis, measles, chickenpox and hemorrhagic fever.
Droplet precautions control the transmission of pneumonias, pertusis, diphtheria, influenza type B, mumps, and meningitis. Droplets transmission occurs when there is adequate contact between the mucous membrane of the nose and mouth or conjunctivae of a susceptible person and large droplets greater than 5 microns (Weinstern, Hierhoizer & Garner 1998: 198).
Percutaneous exposures are the most common routes of exposure to blood-borne pathogens in health care settings. Globally, injections are one of the most common health care procedures and they are often abused. Injection safety practices could significantly reduce occupational risks due to blood-borne pathogens in health care settings. For example, wearing gloves as a protective barrier can reduce the incidence of contamination of the hands but it cannot prevent penetrating injuries caused by needles or other sharp instruments. The CDC (1999) reported that out of 191 health care workers reported to national surveillance in the United States, 55 had reported occupational exposure to HIV, with a baseline negative and subsequent documented seroconversion. Of the 55 health care workers, 47 sustained percutaneous injuries, five had mucocutaneous exposure, and two had both percutaneous and mucocutaneous exposures. In a study conducted by CDC (1997), injections with safety devices reduced injuries by 23%, while the re-use of injection equipment accounted for an estimated 5% of new HIV infections (WHO 2003).
In 1996, CDC published new guidelines, called Standard Precautions, for isolation precautions in hospitals. The standard precautions synthesize the major features of body substance isolation and universal precautions to prevent transmission of a variety of organisms. Standard precautions were developed for use in hospitals and may not necessarily be indicated in other settings where universal precautions are used, such as childcare settings and schools (CDC 1996). Standard precautions is based on the principle that all blood, body fluids, secretions, excretions except sweat, non-intact skin, and mucous membranes may contain transmissible infectious agents. Standard precautions includes a group of infection prevention practices that apply to all patients regardless of whether they have suspected or confirmed infection status in any setting in which healthcare is delivered. These practices include hand hygiene, use of gloves, gown, mask, eye protection or face shield (depending on the anticipated exposure), and safe injection practices. In addition, equipment or items in the patient’s environment likely to have been contaminated with infectious body fluids must be handled in a manner to prevent the transmission of infectious agents.
The application of standard precautions during patient care is determined by the nature of the health care worker-patient interaction and the extent of anticipated blood, body fluid, or pathogen exposure. For some interactions, e.g. performing venipuncture, only gloves may be needed, but for others, e.g. intubations, use of gloves, gown, and face shield or mask and goggles is necessary. Standard precautions are also intended to protect the patient by ensuring that healthcare personnel do not transmit infectious agents to patients through their hands or equipment during patient care (Siegel, Rhinehart, Jackson, Chiarelo and the Health Infection Control Practices Advisory Committee 2007: 13).
Identification of patients infected with blood-borne pathogens cannot be reliably made through medical history and physical examination, and it is not feasible or cost-effective to test all patients for all pathogens prior to giving care. Standard precautions are therefore recommended for use on all patients regardless of diagnosis and treatment setting. Decision regarding the level of precautions to use will depend on the nature of the procedure and not on the actual or assumed serological status of the patient. It is not safe to take precautions only with people from so-called “high-risk groups” because many people belonging to such groups may not necessarily be infected while many infected people may not even be from the high-risk groups.
2.1.2 Components of the Standard Precautions
The infection control problems that emerge during outbreak investigations often indicate the need for new recommendations or reinforcement of existing infection control recommendations to protect patients. Because such recommendations are considered a standard of care and may not be included in other guidelines, they are usually added to the standard precautions. Three such areas of practice that have been added are respiratory hygiene/cough etiquette, safe injection practices and use of masks for the insertion of catheters or injection of material into spinal or epidural spaces via lumbar puncture (e.g. myelogram, spinal or epidural anesthesia) (Siegel et al 2007: 67).
The transmission of SARS-CoV in emergency departments by patients and their family members during the widespread of SARS outbreaks in 2003 highlighted the need for vigilance and prompt implementation of infection control measures at the first point of encounter within a healthcare setting (e.g. reception and triage areas in emergency departments, outpatient clinics, and physician offices). The strategy proposed has been termed respiratory hygiene/cough etiquette and it is intended to be incorporated into infection control practices as a new component of standard precautions. The strategy is targeted at patients and accompanying family members and friends with undiagnosed transmissible respiratory infections, and applies to any person with signs of illness including cough, congestion, rhinorrhea, or increased production of respiratory secretions when entering a healthcare facility. The elements of respiratory hygiene/cough etiquette include:
* education of healthcare facility staff, patients and visitors;
* posted signs in language(s) appropriate to the population served, with instructions to patients and accompanying family members or friends;
* source control measures (e.g. covering the mouth/nose with a tissue when coughing and prompt disposal of used tissues, using surgical masks on the coughing person when tolerated and appropriate);
* hand hygiene after contact with respiratory secretions; and
* spatial separation, ideally more than three feet, of persons with respiratory infections in common waiting areas when possible. Covering sneezes and coughs and placing masks on coughing patients are proven means of source containment that prevent infected persons from dispersing respiratory secretions into the air (Siegel et al 2007: 68).
Masking may be difficult in some settings, e.g. pediatrics, in which case emphasis by necessity may be on cough etiquette. Physical proximity of less than 3 feet has been associated with an increased risk for transmission of infections via the droplet route, e.g. N. meningitidis and group A Streptococcus, and therefore supports the practice of distancing infected persons from others who are not infected. The measures stated above should be effective in decreasing the risk of transmission of pathogens contained in large respiratory droplets, e.g. influenza virus, adenovirus, Bordetella pertussis and Mycoplasma pneumoniae. Healthcare personnel are advised to observe droplet precautions, i.e. wear a mask, and hand hygiene when examining and caring for patients with signs and symptoms of a respiratory infection. Healthcare personnel who have a respiratory infection are advised to avoid direct contact with patients, especially with high-risk patients. If this is not possible, then a mask should be worn while providing patient care (CDC 2007).
2.1.3 Elements of the Standard Precautions
Health care workers should assume that every person is potentially infected or colonized with an organism that could be transmitted in the healthcare setting and, therefore, should apply the following infection control practices while delivering health care (CDC 2007).
2.1.3.1. Hand Hygiene
This has been cited frequently as the most important practice in reducing the transmission of infectious agents in health care settings and it is an essential element of the standard precautions. Hand hygiene includes hand washing with both plain or antiseptic-containing soap and water and the use of alcohol based products (gels, foams or rinses), which do not require the use of water (Siegel et al 2007: 49). Hand hygiene involves:
* avoiding unnecessary touching of surfaces that are close to the patient to prevent contamination of clean hands by environmental surfaces and transmission of pathogens from contaminated hands to surfaces;
* hand washing with either a non-antimicrobial soap and water or an antimicrobial soap and water when hands are visibly dirty, contaminated with proteinaceous material, or visibly soiled with blood or body fluids;
* decontaminating hands in the clinical situations described above if hands are not visibly soiled, or after removing visible material with non-antimicrobial soap and water. The preferred method of hand decontamination is the use of an alcohol-based hand rub, but, alternatively, hands may be washed with an antimicrobial soap and water. However, frequent use of alcohol-based hand rub immediately following hand washing with non-antimicrobial soap may increase the frequency of dermatitis.
Hand hygiene should be performed:
* before having direct contact with patients;
* after having contact with blood, body fluids, excretions, mucous membranes, non- intact skin, or wound dressings;
* after contact with a patient's intact skin, e.g., when taking pulse or blood pressure or lifting a patient;
* if hands will be moving from a contaminated-body site to a clean-body site during patient care;
* after contact with inanimate objects (including medical equipment) in the immediate vicinity of the patient; and
* after removing gloves.
Hand washing with non-antimicrobial soap and water or with antimicrobial soap and water is recommended if contact with spores, e.g. Clostridium difficile or Bacillus anthracis, is likely to have occurred. 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. Artificial fingernails or extenders should not be worn if duties include direct contact with patients at high risk for infection and associated adverse outcomes, e.g. those in intensive care units (ICUs) or operating rooms (Siegel et al 2007: 49). Organizational policy should be developed on the wearing of non- natural nails by healthcare personnel who have direct contact with patients outside of the groups specified above.
2.1.3.2. Personal Protective Equipment
Personal Protective Equipment refers to a variety of barriers used alone or in combination to protect mucous membrane airways, skin and clothings from contact with infectious agents. The selection of PPE depends on the nature of patient interaction and/or the likely mode(s) of transmission (Siegel et al 2007: 49). The following principles of use should be observed:
* PPE should be worn when the nature of the anticipated patient interaction indicates that contact with blood or body fluids may occur.
* Prevent contamination of clothing and skin during the process of removing PPE.
* PPE should be removed and discarded before leaving the patient's room or cubicle.
The following PPE are recommended for implementing standard precautions:
* Gloves
Under standard precautions, gloves should be worn when it can be reasonably anticipated that contact with blood or other potentially infectious materials, mucous membranes, non- intact skin, or potentially contaminated intact skin, e.g. of a patient incontinent of stool or urine, could occur. Gloves with fit and durability appropriate to the task should be used. Disposable medical examination gloves should be worn for providing direct patient care such as wound dressing, phlebotomy, setting intravenous infusion, etc.
For cleaning the environment or medical equipment, disposable medical examination gloves or re-usable utility gloves should be worn. Gloves should be removed after contact with a patient and/or the surrounding environment (including medical equipment) using proper techniques to prevent hand contamination. The same pair of gloves should not be worn for the care of more than one patient and gloves should not be re-used, because this practice has been associated with the transmission of pathogens.
Gloves should be changed during patient care if the hands will move from a contaminated body site, e.g. perineal area, to a clean body site, e.g. face (Siegel et al 2007: 50).
* Gowns
Gowns should be appropriate for protecting the skin and preventing soiling or contamination of clothing during procedures and patient care when contact with blood, body fluids, secretions, or excretions is anticipated. A gown should be worn for direct patient contact if the patient has uncontained secretions or excretions and it should be removed and hand hygiene performed before leaving the patient’s environment. Gowns should not be re-used even for repeated contacts with the same patient. Routine donning of gowns upon entrance into a high-risk unit, e.g. intensive care unit, is not indicated (Siegel et al 2007: 51).
* Mouth, Nose, and Eye Protection
PPE should be used to protect the mucous membranes of the eyes, nose and mouth during procedures and patient care activities that are likely to generate splashes or sprays of blood, body fluids, secretions and excretions. Select masks, goggles, face shields, and combinations of each according to the need anticipated by the task to be performed.
A face shield that fully covers the front and sides of the face or a mask and goggles (in addition to gloves and gown) should be worn during aerosol-generating procedures, e.g. bronchoscopy, suctioning of the respiratory tract (if not using in-line suction catheters), and endotracheal intubation in patients who are not suspected of being infected with an agent for which respiratory protection is otherwise recommended, e.g. M. tuberculosis, SARS or hemorrhagic fever viruses.
2.1.3.3 Respiratory Hygiene/Cough Etiquette
Healthcare personnel should be educated on the importance of source control measures in containing respiratory secretions to prevent droplet and fomite transmission of respiratory pathogens, especially during seasonal outbreaks of viral respiratory tract infections in communities, e.g. influenza, adenovirus, parainfluenza virus.
The following measures should be implemented to contain respiratory secretions in patients and accompanying individuals who have signs and symptoms of a respiratory infection, beginning at the point of initial encounter in a healthcare setting, e.g. triage, reception, and waiting areas in emergency departments, outpatient clinics, and physician offices:
* Post signs at entrances and in strategic places, e.g. elevators and cafeterias, within ambulatory and in-patient settings with instructions to patients and other persons with symptoms of a respiratory infection to cover their mouth/nose when coughing or sneezing, use and dispose of tissues, and perform hand hygiene after hands have been in contact with respiratory secretions.
* Provide tissues and no-touch receptacles, e.g. foot pedal operated lid or open and plastic-lined waste basket, for disposal of tissues.
* Provide resources and instructions for performing hand hygiene in or near waiting areas in ambulatory and in-patient settings; provide conveniently located dispensers of alcohol-based hand rubs and, where sinks are available, supplies for hand washing.
* During periods of increased prevalence of respiratory infections in the community, e.g. as indicated by increased school absenteeism, increased number of patients seeking care for a respiratory infection, offer masks to coughing patients and other symptomatic persons, e.g. persons who accompany ill patients, upon entry into the facility or medical office and encourage them to maintain special separation, ideally a distance of at least 3 feet from others in common waiting areas. Some facilities may find it logistically easier to institute this recommendation year round as a standard of practice (Siegel et al 2007: 80).
2.1.3.4 Patient Placement
The potential for transmitting infectious agents should be included in patient placement decisions. Patients who pose a risk for transmission to others, e.g. uncontained secretions, excretions or wound drainage and infants with suspected viral respiratory or gastrointestinal infections, should be placed in a single-patient room when available.
Patient placement should be based on the following principles:
* Route(s) of transmission of the known or suspected infectious agent
* Risk factors for transmission in the infected patient
* Risk factors for adverse outcomes resulting from a hospital acquired infection (HAI) in other patients in the area or room being considered for patient placement
* Availability of single-patient rooms
* Patient options for room sharing, e.g., cohort patients with the same infection (Siegel et al 2007: 81).
2.1.3.5 Patient Care Equipment and Instruments/Devices
Policies and procedures should be established for containing, transporting, and handling patient care equipment and instruments/devices that may be contaminated with blood or body fluids. Organic materials should be removed from critical and semi-critical instruments/devices using recommended cleaning agents before high-level disinfection and sterilization to enable effective disinfection and sterilization processes (Siegel et al 2007: 81).
PPE should be used according to the level of anticipated contamination when handling patient care equipment and instruments/devices that are visibly soiled or may have been in contact with blood or body fluids (Siegel et al 2007: 81).
2.1.3.6 Care of the Environment
Policies and procedures should be established for routine and targeted cleaning of environmental surfaces as indicated by the level of patient contact and degree of soiling. Surfaces that are likely to be contaminated with pathogens should be cleaned and disinfected more frequently, including those surfaces that are close to the patient (e.g. bed rails, over bed tables) and frequently touched in the patient care environment (e.g. door
knobs, surfaces in and surrounding toilets in patient rooms), compared to other surfaces (e.g. horizontal surfaces in waiting rooms).
The efficacy of in-use disinfectants should be reviewed when evidence of continuing transmission of an infectious agent (e.g. rotavirus, C. difficile, norovirus) may indicate resistance to the in-use product and change to a more effective disinfectant as indicated.
In facilities that provide health care to pediatric patients or have waiting areas with child play toys, e.g. obstetric/gynecology offices and clinics, policies and procedures should be established for cleaning and disinfecting toys at regular intervals. Use the following principles in developing such policy and procedures:
* Select play toys that can be easily cleaned and disinfected.
* Do not permit use of stuffed furry toys if they will be shared.
* Clean and disinfect large stationary toys (e.g. climbing equipment) at least once a week and whenever visibly soiled.
* If toys are likely to be mouthed, rinse with water after disinfection or wash in a dishwasher.
* When a toy requires cleaning and disinfection, do so immediately or store in a designated labeled container separate from toys that are clean and ready for use.
Multi-use electronic equipment should be included in policies and procedures for preventing contamination and for cleaning and disinfection, especially those items that are used by patients, those used during delivery of patient care, and mobile devices that are moved in and out of patient rooms frequently (Siegel et al 2007: 82).
2.1.3.7 Textiles and Laundry
Used textiles and fabrics should be handled with minimum agitation to avoid contamination of air, surfaces and persons. If laundry chutes are used, ensure that they are properly designed, maintained, and used in a manner to minimize dispersion of aerosols from contaminated laundry (Siegel et al 2007: 82).
2.1.3.8 Safe Injection Practices
The following recommendations apply to the use of needles, cannulas that replace needles, and, where applicable, intravenous delivery systems.
* Use aseptic technique to avoid contamination of sterile injection equipment.
* Do not administer medications from a syringe to multiple patients, even if the needle or cannula on the syringe is changed. Needles, cannulae, and syringes are sterile, single-use items; they should neither be re-used for another patient nor allowed to contact a medication or solution that might be used for another patient.
* Fluid infusion and administration sets, i.e. intravenous bags, tubing and connectors, should be used for one patient only and disposed appropriately after use. Consider a syringe or needle/cannula contaminated once it has been used to enter or connect to a patient’s intravenous infusion bag or administration set.
* Use single-dose vials for parenteral medications whenever possible.
* Do not administer medications from single-dose vials or ampoules to multiple patients and do not combine leftover contents for later use.
* If you must use multidose vials, both the needle or cannula and syringe used to access the multidose vial must be sterile.
* Do not keep multidose vials in the immediate patient treatment area; store in accordance with the manufacturer's recommendations and discard if sterility is compromised or questionable.
* Do not use bags or bottles of intravenous solution as a common source of supply for multiple patients (Siegel et al 2007: 83).
2.1.3.9 Infection Control Practices for Special Lumbar Puncture Procedures
Always wear a surgical mask when placing a catheter or injecting material into the spinal canal or subdural space, i.e. during myelograms, lumbar puncture and spinal or epidural anesthesia (Siegel et al 2007: 83).
2.1.4 Transmission-based Precautions
Transmission-based precautions are for patients documented or suspected to be infected with highly transmissible or epidemiologically important pathogens, for which additional precautions beyond the standard precautions are needed to interrupt transmission in hospitals. There are three types of transmission-based precautions: air-borne precautions, droplet precautions, and contact precautions. They may be combined for diseases that have multiple routes of transmission and when used either singularly or in combination, they should be used in addition to the standard precautions. Transmission-based precautions remain in effect for a limited period, i.e. while the risk of transmission persists or for the duration of the illness, then they are discontinued. The duration for most infectious diseases reflects known patterns of persistence and shedding of infectious agents associated with the natural history of the infectious process and treatment (Siegel et al 2007: 72).
Air-borne precautions are to reduce the risk of air transmission of infectious agents. Air transmission occurs through the dissemination of either air-borne droplet nuclei (small- particle residues {5 µm or smaller} of evaporated droplets that may remain suspended in the air for long periods) or dust particles containing the infectious agent. Microorganisms carried in this manner can be dispersed widely by air currents and may become inhaled by or deposited on a susceptible host within the same room or over a longer distance from the source patient, depending on environmental factors. Therefore, special air handling and ventilation are required to prevent air transmission.
Air-borne precautions apply to patients known or suspected to be infected with epidemiologically important pathogens that can be transmitted by air, such as M. tuberculosis, measles, chickenpox, and disseminated herpes zoster. In acute care hospital and long-term setting, it involves placement of the patient in an air-borne infection isolation room (AIIR). AIIR is a single-patient room that is equipped with special air handling and ventilation capacity that meet the required standards, i.e. monitored negative pressure relative to the surrounding area, 12 air exchanges per hour for new construction and renovation and 6 air exchanges per hour for existing facilities, and air exhausted directly to the outside. In the event of an outbreak or exposure involving large number of patients who require air-borne precautions, it also involves placing together (cohorting) patients
who are presumed to have the same infection (based on clinical presentation and diagnosis when known) in areas of the facility that are away from other patients, especially patients who are at increased risk for infection (e.g. immunocompromised patients). Again, air-borne precautions can be applied in this setting using temporary portable solutions, e.g. exhaust fan, to create a negative pressure environment in the converted area of the facility and discharging air directly to the outside, away from people and air intakes (Siegel et al 2007: 71).
In ambulatory setting, air-borne precautions include developing systems, e.g. triage, and signage, to identify patients with known or suspected infections that require air-borne precautions upon entry into ambulatory settings. Place the patient in an AIIR as soon as possible. If an AIIR is not available, place a surgical mask on the patient and place him/her in an examination room. Once the patient leaves, the room should remain vacant for the appropriate time, generally one hour, to allow full exchange of air. Instruct patients with a known or suspected air-borne infection to wear a surgical mask and observe respiratory hygiene/cough etiquette. Once in an AIIR, the mask may be removed but should remain on if the patient is not in an AIIR (Siegel et al 2007: 88).
Droplet precautions are to reduce the risk of droplet transmission of infectious agents. Droplet transmission involves contact of the conjunctivae or the mucous membranes of the nose or mouth of a susceptible person with large-particle droplets (larger than 5 µm) containing microorganisms generated from a person who has a clinical disease or who is a carrier of the microorganism. Droplets are generated from the source person primarily during coughing, sneezing, or talking and while performing certain procedures such as suctioning and bronchoscopy. Transmission via large-particle droplets requires close contact between the source and recipient persons, because droplets do not remain suspended in the air and generally travel only short distances, usually 3 ft or less, through the air. Because droplets do not remain suspended in the air, special air handling and ventilation are not required to prevent droplet transmission.
Droplet precautions apply to any patient known or suspected to be infected with epidemiologically important pathogens that can be transmitted by infectious droplets, e.g.
B. pertussis, influenza virus, adenovirus, rhinovirus, N. meningitides, etc. A single patient
room is preferred for patients who require droplet precautions. When a single-patient room is not available, consultation with infection control personnel is recommended to assess the risks associated with other patient placement options, e.g. cohorting or keeping the patient with an existing roommate. Spatial separation of patients by > 3 feet and drawing the curtain between patient beds is especially important for patients in multi-bed rooms with infections transmitted through droplets. Healthcare personnel should wear a mask for close contact with infectious patients upon entry into the room. Patients on droplet precautions who must be transported outside of the room should wear a mask if tolerated and they should observe respiratory hygiene/cough etiquette.
Contact precautions are to reduce the risk of transmitting epidemiologically important microorganisms through direct or indirect contact. Direct contact transmission involves skin-to-skin contact and physical transfer of microorganisms to a susceptible host from an infected or colonized person. This occurs when personnel turn patients, bathe patients, or perform other patient care activities that require physical contact. Direct contact transmission can also occur between two patients, e.g. through hand contact, with one serving as the source of infectious microorganisms and the other as a susceptible host (Siegel et al 2007: 70).
Indirect contact transmission involves contact of a susceptible host with a contaminated intermediate object, usually inanimate, in the patient's environment. Contact precautions apply to specified patients known or suspected to be infected or colonized (presence of microorganism in or on patient but without clinical signs and symptoms of infection) with epidemiologically important microorganisms that can be transmitted through direct or indirect contact. Contact precautions also apply where the presence of excessive wound drainage, fecal incontinence, or other discharges from the body suggest an increased potential for extensive environmental contamination and risk of transmission. A single patient room is preferred for patients who require contact precautions. In multi-patient rooms, place together in the same room (cohort) patients who are infected or colonized with the same pathogen and are suitable roommates. Ensure more than 3 feet spatial separation between beds and draw the privacy curtain between beds to minimize opportunities for direct contact and reduce opportunities for inadvertent sharing of items between the infected/colonized patient and other patients. Healthcare personnel caring for
patients on contact precautions should wear a gown and gloves for all interactions that may involve contact with the patient or potentially contaminated areas in the patient’s environment. Don PPE before entering and discard before exiting the patient room to contain pathogens, especially those that have been implicated in transmission through environmental contamination (Siegel et al 2007: 72).
2.1.5 Common Infections Transmissible through Occupational Exposure Three common infectious pathogens known to be transmissible through occupational exposure are HBV, HCV and HIV. The risk of transmission of these pathogens to health care workers depends on the prevalence of the disease in the patient population as well as the nature and frequency of exposures. Transmission of HBV, HCV and HIV can occur through occupational exposure due to percutaneous injury (needle stick or other sharps injury), mucocutaneous exposure (splash of blood or other body fluids into the eye, mouth or nose), or blood contact with non-intact skin. However, percutaneous injury, precisely needle stick injury, is the most common form of occupational exposure and the most likely to result in infection. Among 35 million health care workers worldwide, about 3 million experience percutaneous exposure to blood-borne pathogens each year; 2 million to HBV,
0.9 million to HCV and 750,000 to HIV. These injuries may result in 15,000 HCV, 70,000 HBV and 1000 HIV infections and more than 90% of these infections occur in developing countries (WHO 2003).
2.1.5.1 Hepatitis B Virus (HBV) Infection
HBV infection is a major infectious hazard for health care workers, and 5-10% of HBV- infected workers become chronically infected. Persons with chronic HBV infection are at risk for chronic liver disease (i.e. chronic active hepatitis, cirrhosis and primary hepatocellular carcinoma) and are potentially infectious throughout their lifetime (CDC 1997: 3). The risk of HBV infection is primarily related to the degree of contact with blood in the workplace and to the hepatitis Be antigen (HBeAg) status of the source person (CDC 2001: 3-4). The risk of acquiring HBV infection from occupational exposure depends on the frequency of percutaneous and permucosal exposures to blood or body fluids containing blood (Thomas, Factor, & Gabon, 1993: 1705). Although percutaneous injuries are among the most efficient modes of HBV transmission, percutaneous exposures probably account for only a minority of HBV infections among HCWs.
In several investigations of nosocomial hepatitis B outbreaks, most infected HCWs could not recall an overt percutaneous injury (Garibaldi, Hatch Bisno, Hatch, & Greg, 1972: 963- 6). However, in some studies, up to one-third of infected HCWs recalled caring for a patient who was HBsAg-positive (Callender, White, Williams, 1982: 324). In addition, HBV has been demonstrated to survive in dried blood at room temperature on environmental surface for at least one week. Thus, HBV infections that occur in HCWs with no history of non-occupational exposure or occupational percutaneous injury might have resulted from direct or indirect blood or body fluid exposures that inoculated HBV into cutaneous scratches, abrasions, burns, other lesions, or mucosal surfaces (Francis, Favero, & Maynard,. 1981: 27- 32; Lauer, VanDrunen, Washburn, & Balfour, 1979: 513).
Blood contains the highest HBV titers of all body fluids and it is the most important medium of transmission in the healthcare setting. HBsAg is also found in several other body fluids, including breast milk, bile, cerebrospinal fluid, feaces, nasopharyngeal washings, saliva, semen, sweat and synovial fluids (Bond, Peterson, & Favero, 1977: 235- 52). However, the concentration of HBsAg in the body fluid can be 100-1000 folds higher than the concentration of infectious HBV particles. Therefore, most body fluids are not efficient vehicles of transmission because they contain low quantities of infectious HBV, despite the presence of HBsAg. Because of the high risk of HBV infection among HCWs, routine pre- exposure vaccination of HCWs against hepatitis B and the use of standard precautions to prevent exposure to blood and other potentially infectious body fluids have been recommended since 1980s (CDC 1982: 317).
2.1.5.2 Hepatitis C Virus (HCV) Infection
Hepatitis C virus is one of the hepatitis agents known to be transmitted through blood and blood products. HCV has been implicated as a major cause of chronic liver disease and hepatocelluar carcinoma worldwide, but the risk of occupational transmission of HCV is low. The average incidence of anti-HCV seroconversion after accidental percutaneous exposure from an HCV positive source is 1.8% (range 0–7%) (Lamphear, Linnemann, Cannon, DeRonde, Pendy, & Kerley, 1994: 745). One study showed that transmission occurred only from hollow-bore needles (Puro, Petrosillo & Ippollito, 1995: 273). Transmission in HCWs rarely occurs from mucous membrane exposures to blood; no transmission in HCWs has been documented from intact or non-intact skin exposures to
blood (CDC 2001:6). A prevalence of 6% HCV infection has been reported among healthy blood donors in a Nigerian population in Jos (Egah, Madong, Iya, Gomwalk, Audu, Banwat, & Orile, 2004: 35). The highest prevalence of 12.3% of hepatitis C antibody so far reported among volunteer blood donors in Nigeria was in a study conducted at the University of Benin Teaching Hospital (Halim, & Ajayi, 2000: 410). The disease prevalence in a population is one of the determinants of the risk of infection transmission among HCWs. There is therefore a need to pay attention to HCV infection among HCWs in Nigeria.
2.1.5.3 Human Immunodeficiency Virus
The seroprevalence of HIV varies widely from country to country and from one region to another within the same country. Sub-Saharan Africa (SSA) has the highest HIV seroprevalence in the world. The 2005 sero-sentinel survey conducted in Nigeria reported an overall HIV seroprevalence of 4.4% (Federal Ministry of Health 2006:13). This high prevalence in the country poses an occupational risk to HCWs. The average risk of HIV transmission after percutaneous exposure to HIV infected blood has been estimated to be approximately 0.3% (Bell, 1997: 9) and after a mucous membrane exposure approximately 0.09% (Ippolito, Puro, & DeCarli, 1993: 1451-8). Cases of HIV transmission after non- intact skin exposure have been documented (CDC 1997: 285).
Various studies suggest that several factors may influence the risk of HIV transmission after occupational exposure. In a retrospective study of HCWs who had percutaneous exposure to HIV, the risk for HIV infection was found to be increased with exposure to a larger quantity of blood from the source person. A needle that was visibly contaminated with the patient’s blood was placed directly in a vein or artery (Cardo, Culver, & Ciesielski,. 1997: 1485-90).
2.1.6 Post-exposure Management
Exposure prevention by adhering to standard precautions remains the primary strategy for the prevention of infections due to occupational exposure. Nevertheless, occupational exposure sometimes occurs; therefore, appropriate post-exposure management is important for workplace safety. Health care facilities should make available a system that includes written protocols for prompt reporting, evaluation, counseling, and treatment as
well as follow-up of occupational exposures that might place HCWs at risk for acquiring infections. Again, HCWs should be educated on the risk for and prevention of infections, including the need to be vaccinated against hepatitis B (CDC 1989; CDC 1991; Garner, 1996: 54).
2.1.6.1 Post-exposure Prophylaxis for HIV
Post-exposure prophylaxis is an important part of post-exposure management. PEP for HIV involves initiation of antiretroviral regimen as soon as possible preferably within hours rather than days of exposure. The recommended PEP regimen involves the use of two or three antiretroviral agents, depending on the level of risk for HIV transmission represented by the exposure. If PEP is offered and taken and the source is later determined to be HIV negative, PEP should be discontinued. However, concerns have been expressed regarding HIV negative sources being in window period for conversion (CDC 2005: 2-11).
2.1.6.2 Post-exposure Prophylaxis for HBV Infection
Post-exposure prophylaxis for HBV infection involves the combination of hepatitis B immune globulin (HBIG) and hepatitis B vaccine. For perinatal exposure to an HBsAG, HBeAg positive mother, a regimen combining HBIG and initiation of the hepatitis B vaccine series at birth is 85–95% effective in preventing HBV infection. In the occupational setting, multiple doses of HBIG initiated within one week following percutaneous exposure to HBsAg positive blood will provide an estimated 75% protection from HBV infection (CDC 2001:4).
Ensure access to clinicians who can provide post-exposure care during all working hours including nights and weekends. HBIG, hepatitis vaccine, and antiretroviral drugs for HIV post-exposure prophylaxis should be made available for timely administration (either by providing access on-site or by creating linkages with other facilities or providers). Persons responsible for providing post-exposure management should be familiar with the evaluation, treatment protocols, and facility plan for accessing HBIG, hepatitis B vaccine and antiretroviral drugs for HIV PEP. All HCWs should be educated to report occupational exposures immediately after they occur, particularly because HBIG, hepatitis B vaccine and HIV PEP are most likely to be effective if administered as soon as possible after exposure. HCWs that are at risk of occupational exposure to infective organisms should be
familiar with the principles of post-exposure management as part of their job orientation and ongoing job training (CDC 2001: 16).
2.1.7 Immunization
Because of their contact with patients or infective materials from patients, many HCWs are at risk of exposure and possible transmission of some vaccine-preventable diseases. Maintenance of immunity is therefore an essential part of prevention and infection control programs for HCWs. Optimal use of immunizing agents safeguards the health of workers and protects patients from becoming infected through exposure to infected workers. Consistent immunization program could substantially reduce both the number of susceptible HCWs in hospitals and attendant risk of transmitting vaccine-preventable diseases to other workers and patients. Any medical facility that provides direct patient care is encouraged to formulate a comprehensive immunization policy for all health care workers (CDC 1997: 1). On the basis of documented nosocomial transmission, HCWs are considered to be at significant risk of acquiring or transmitting hepatitis B, influenza, measles, mumps, rubella, and varicella, all of which are vaccine-preventable and for which immunization is strongly recommended (CDC 1997: 3).
2.2 Knowledge of Standard Precautions
Knowledge refers to a recall of information and it is a pre-requisite to appropriate behavioral change. It is the most important tool for effecting behaviour change (Gbefwi 2004: 36). The linkage between knowledge and behaviour has been stated in the cognitive behaviour theory, which states that behaviour is mediated through cognition and that knowledge is necessary but not sufficient to produce behaviour change (Glanz & Rimer 2001:16; National Cancer Institute 2005: 12). This section reviews available literature on the knowledge of health care workers of standard precautions.
A study to assess the knowledge and compliance with universal precautions and their perceived risk of infection at the workplace in Ibadan, showed poor knowledge of and compliance with standard precautions. Some 77.5% of the respondents were aware but only 24% had the correct knowledge of the universal precautions. Knowledge was highest (36.9%) among surgical and medical residents; it was 10.8% among laboratory medicine residents and 15.4% among interns. Significantly, senior registrars had better knowledge
than junior doctors (Kolude, Omokhodion & Owoaje 2004). A similar study was conducted in Ile-Ife, Nigeria, on the knowledge and practice of universal precautions among qualifying medical and nursing students. Out of 129 students consisting of 103 medical students and 26 nursing students, 83 (64.3%) were familiar with the concept of universal precautions. There was a higher level of knowledge among nursing students (77%) than among medical students (61%). Knowledge of what constitutes the universal precautions was low among the students. Only 38.8% had good knowledge of the precautionary measures. Prevalence of needle stick injury was high (41.8% of total population) among the study population; 39.8% among medical students and 50% among nursing students (Bamigboye & Adesanya 2006: 112-116). This high prevalence of needle stick injury is an evidence of poor adherence to standard precautions.
In another study on knowledge, attitude and practices among health care workers (nurses and paramedical staff) in Sharourah, Kingdom of Saudi Arabia, 21% of nurses and 30% of paramedics were unaware that HIV and hepatitis C can be transmitted through needle stick injury. Some 74% of the respondents had a history of needle stick injury, of which only 7% reported the injuries to a doctor for post-exposure prophylaxis. Some 27% used gloves for phlebotomy procedure always and 29% felt that needles could be recapped after use. Only 61% of the respondents were aware of the universal precautions (Alam 2002: 395).
Another study carried out on health care workers from a tertiary hospital and two state government-owned secondary health care hospitals in Ibadan, Nigeria, showed that only the tertiary hospital had a safety policy. Identified barriers to infection control included lack of equipment, inadequate reporting system, and inadequate funding for the workers. The same study showed that 89.1% of the HCWs were routinely in contact with body fluids and blood at work and 82.5% reported ever having an accidental splash with body fluids, with blood being the reported fluid in 69.3% and urine in 50.0% of cases. Laboratory personnel were at greatest risk for contact, followed by surgeons. Needle pricks occurred in 59.8% of cases while medication vials were responsible for 22.2%. Sharp injuries were commonest among surgeons. Up to 90.8% of the workers had ever heard about standard precautions but inadequate fund and equipment hindered them from practicing it (Lawoyin, Stringer, Taines & Oluwatosin 2005).
2.3 Practice of Standard Precautions
Health care workers may have similar training but their behavior may vary according to their perception of risk. Some of the reasons health care workers gave for not complying with universal precautions are habit, lack of time, interference with procedures, discomfort with protective equipment, lack of supplies, carelessness, concern for costs, unexpected body fluid contact, and the possibility inciting fear in patients. The universal precautions have been in place since 1987, but there has been extensive documentation of sub- optimal adherence especially in the developing countries. However, non-compliance among health care workers may vary according to workplace setting, whether rural or urban.
A study conducted among health care workers in rural north India, showed low compliance with eye protective wears. A high proportion of health care workers were not complying with needle recapping precautions. The study also showed that compliance with standard precautions was associated with being on the job for a longer period, knowledge of blood- borne pathogen transmission and strong commitment to workplace safety. The study suggested that interventions to improve compliance to standard precautions among health care workers in rural north India should address knowledge and understanding as well as safety measures by the employee’s organizations (Kermode, Jolley, Langkham, Thomas, Holmes & Gifford 2005: 27-33).
A related study conducted among health care workers in public and private health care facilities in Abeokuta metropolis in Nigeria showed that about one-third of all respondents always recapped used needles. Use of re-capped needles was highest among doctors but less among trained nurses. Less than two-thirds (63%) of the respondents always used personal protective equipment, but more than half (56.5%) had never worn goggles during deliveries and surgeries. Almost all (94.5%) of the health care workers observed hand washing after handling patients (Sadoh, Fawole, Sadoh, Oladimeji & Sotiloye 2006:722-6).
Odusanya in 2003 conducted a study on awareness and compliance with universal precautions amongst health workers at an emergency medical service in Lagos, Nigeria, and found that the group of health workers had good knowledge about exposure risks at work but did not translate their knowledge into safe work practices. Only 42% of the respondents complied with the universal precautions.