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Element III: Engineering and Work Practice Controls, Con't.
Work Practice Controls
In addition to risks related to device characteristics described above under engineering controls, there are risks associated with how a task is performed. Work Practice Controls, also known as administrative controls, include policies and procedures regarding work practices that reduce or eliminate the likelihood of exposure by altering the manner in which a task is performed.
Some circumstances or practices increase opportunities for exposure to infectious material; these include percutaneous exposure, mucous membrane/non-intact skin exposure and parenteral exposure.
Development and Implementation of Work Practice Controls: These include the evaluation and revision of the way in which high-risk tasks are performed, such as hand washing and respiratory protection.
Needlestick injuries have been associated with certain work practices such as
- Recapping;
- Transferring a body fluid between containers; and
- Failing to properly dispose of used needles in puncture-resistant sharps containers.
Past studies of needlestick injuries have shown that 10% to 25% occurred when recapping a used needle (Ruben, et al., 1983; Krasinski, et al., 1987; McCormick & Maki, 1981; McCormick, et al., 1991; Yassi & McGill, 1991). Although recapping by hand has been discouraged for some time and is prohibited under the OSHA bloodborne pathogens standard (19 CFR 1910.1030) unless no alternative exists, 5% of needlestick injuries in NaSH hospitals are still related to this practice (Figure 2). Injury may occur when a healthcare worker attempts to transfer blood or other body fluids from a syringe to a specimen container, such as a vacuum tube, and misses the target. Also, if used needles or other sharps are left in the work area or are discarded in a sharps container that is not puncture resistant, a needlestick injury may result.
Whenever a needle or other sharp device is exposed, injuries can occur. Data from NaSH show that approximately 38% of percutaneous injuries occur during use and 43% occur after use and before disposal. Causes of percutaneous injuries with hollow-bore needles are shown in Figure 2. 
Figure 2. Causes of percutaneous injuries with hollow-bore needles in NaSH hospitals, by % total percutaneous injuries (n=3,057), June 1995 - July 1999. (Source: CDC [1999].) Percutaneous exposures occur when the skin is pierced, causing a point of entry for blood or other infectious material. Percutaneous injury can occur through handling, disassembly, disposal, reprocessing of needles and other sharps, manipulating needles and other sharps by hand, recapping, removing scalpel blades. During some procedures, such as blind suturing, there is opportunity for injury, due to poor visualization, which can expose the patient as well as the healthcare worker. Whenever the non-dominant hand is opposing or next to a sharp or when bone spicules or metal fragments are present, the risk of percutaneous injury is greater.
Mucous membrane/non-intact skin exposures also increase the risk of exposure to infection. Direct contact with blood or body fluid can occur, as well as through splashing or sprays of blood or body fluid.
Parenteral exposures occur with injection with infectious material or an infusion of contaminated blood products. Transplantation of contaminated organs/tissues also results in parenteral exposure.
Work practice controls begin with an evaluation of the task being done to determine if it is being accomplished in the safest way possible. Work practice controls that help to reduce the risk of exposure to infections include efforts to modify procedures in order to avoid injury. Some examples include:
- Utilizing a safer device whenever possible
- Passing sharp instruments by use of designated "safe zones".
- Disassembling sharp equipment by use of forceps or other devices.
- Using forceps, suture holder, or other instruments for suturing.
- Using forceps rather than fingers for holding tissue.
- Not leaving sharps on a field.
- Hand washing.
- Prompt cleaning of blood and body fluid spills.
- Containing the spill so that exposure to other individuals, equipment, or instruments is prevented until cleaned up.
- Wearing appropriate personal protective equipment (PPE) - gloves are mandatory, gowns/aprons are used depending on extent of spill.
- Wiping up blood with disposable cloth, pour diluted bleach solution (1/4 cup household bleach to 1 gallon water) or other EPA approved agent directly onto the surface, let sit 10 minutes, then wipe with second disposable cloth.
- Bagging the medical waste according to policy and procedure in your facility; the bag should be labeled with biohazard sign.
- Worker training and education, for example, this New York State mandatory training in infection control for licensure or relicensure certain health professionals, as well as annual reviews in most healthcare facilities.
- Monitoring for safe work practices. This is not only an individual professional responsibility, but also quality assurance; risk management and health and safety committees are among those responsible for safe work practices.
Identifying Those at Risk for Exposure
Those at risk for exposure include healthcare workers who are performing a procedure, any assistants in a procedure, those who are near or are observing the performance of a procedure and ancillary personnel. Based on this definition, most of the more than 8 million healthcare workers in the United States are at risk for exposure.
Between 1985 and 2000 (the most current available information), 56 "documented" cases and 138 "possible" cases of occupational Human Immunodeficiency Virus (HIV) transmission cases were reported to the Centers for Disease Control and Prevention (CDC, 2000) (See Table 1). Nurses and laboratory technicians were most often involved. Percutaneous injury, or needlestick injury, accounted for 49 (89%) of the documented transmissions. Of these, 44 involved hollow-bore needles used for blood collection or insertion of an IV catheter (NIOSH, 1999).
Multiple studies have been conducted to estimate the rate of HIV transmission to workers who were exposed to HIV infected blood through percutaneous injury. Of 6,498 exposures studied, 21 infections followed, for an average transmission rate of 0.3% per injury. Additionally, studies have indicated that the risk of HIV transmission increased when the worker was exposed to a large quantity of blood from a patient, as indicated by (1) a visibly bloody device, (2) a procedure that involved placing a needle in a patient's vein or artery, or (3) a deep injury (NIOSH, 1999). Table 1. Healthcare workers with documented and possible occupationally acquired AIDS/HIV infection, by occupation, reported through June 2000, United States¹
|
Occupation |
Documented
Occupational
Transmission2 |
Possible Occupational Transmission3 |
|
Dental worker, including dentist |
-- |
6 |
|
Embalmer, morgue technician |
1 |
2 |
|
Emergency medical technician, paramedic |
-- |
12 |
|
Health aide, attendant |
1 |
15 |
|
Housekeeper/maintenance worker |
2 |
13 |
|
Laboratory technician, clinical |
16 |
17 |
|
Laboratory technician, non-clinical |
3 |
-- |
|
Nurse |
23 |
35 |
|
Physician, non-surgical |
6 |
12 |
|
Physician, surgical |
-- |
6 |
|
Respiratory therapist |
1 |
2 |
|
Technician, dialysis |
1 |
3 |
|
Technician, surgical |
2 |
2 |
|
Technician/therapist, other than those listed above |
-- |
9 |
|
Other healthcare occupations |
-- |
4 |
|
|
|
|
Total
|
56 |
138 |
- Healthcare workers are defined as those persons, including students and trainees, who have worked in a health care, clinical, or HIV laboratory setting at any time since 1978. See MMWR 1992;41:823-25.
- Healthcare workers who had documented HIV seroconversion after occupational exposure or had other laboratory evidence of occupational infection: 48 had percutaneous exposure, 5 had mucocutaneous exposure, 2 had both percutaneous and mucocutaneous exposures, and 1 had an unknown route of exposure. Forty-nine healthcare workers were exposed to blood from an HIV-infected person, 1 to visibly bloody fluid, 3 to an unspecified fluid, and 3 to concentrated virus in a laboratory. Twenty-five of these healthcare workers developed AIDS.
- These healthcare workers have been investigated and are without identifiable behavioral or transfusion risks; each reported percutaneous or muco-cutaneous occupational exposures to blood or body fluids, or laboratory solutions containing HIV, but HIV seroconversion specifically resulting from an occupational exposure was not documented.
Hepatitis B (HBV) infections have declined significantly due to widespread immunization of healthcare workers with the hepatitis B vaccine, the use of standard precautions and the OSHA Bloodborne Pathogens Standard. In 1983 17,000 new Hepatitis B infections were estimated among healthcare workers. In 1995, that number declined to 800, a 95% reduction in new cases of HBV. The CDC (1999) reports that since 1994, the number of Hepatitis B infections among healthcare workers has remained steady at approximately 800 annually.
After a single needlestick exposure to HBV infected blood or body fluid, the rate of HBV transmission to susceptible healthcare workers ranges from 6% to 30%. This applies only to those healthcare workers who are not immunized against HBV or who have not had prior infection. Those persons who have antibodies to HBV either from pre-exposure vaccination or prior infection are not at risk.
However, the CDC identifies that only a fraction of healthcare workers are exposed to HBV through percutaneous injuries. While needlesticks are among the most efficient modes of HBV transmission, these exposures probably account for only a minority of HBV infections among healthcare workers . In several investigations of nosocomial hepatitis B outbreaks, most infected healthcare workers could not recall an overt percutaneous injury, although in some studies, up to one third of infected healthcare workers recalled caring for a patient who was HBsAg-positive. In addition, HBV has been demonstrated to survive in dried blood at room temperature on environmental surfaces for at least 1 week. It is possible that HBV infections occurring in healthcare workers 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 on mucosal surfaces (CDC, 2001).
The rate of infection in healthcare workers with Hepatitis C (HCV) after needlestick or other percutaneous injury averages 1.8% (Alter, 1997). Currently, no vaccine exists to prevent HCV infection. Preventing needlestick injury is the best approach to reducing the risk of infection with HCV. According to the CDC, HCV is not transmitted efficiently through occupational exposures to blood. The average incidence of anti-HCV seroconversion after accidental percutaneous exposure from an HCV-positive source is 1.8%, with one study indicating that transmission occurred only from hollow-bore needles compared with other sharps. Transmission rarely occurs from mucous membrane exposures to blood, and no transmission in healthcare providers has been documented from intact or nonintact skin exposures to blood. Data are limited on survival of HCV in the environment. In contrast to HBV, the epidemiologic data for HCV suggest that environmental contamination with blood containing HCV is not a significant risk for transmission in the healthcare setting, with the possible exception of the hemodialysis setting where HCV transmission related to environmental contamination and poor infection-control practices have been implicated (CDC, 2001).
Exposure to needlestick injury increases the risk of acquiring serious or fatal infections. More than 20 other infections, other than HIV, HVB, and HVC, can be transmitted through needlesticks, including: tuberculosis, syphilis, malaria and herpes (ANA, 1999). The ramifications of such an injury touch every aspect of a person's life, physically, emotionally, professionally, socially, and spiritually.
In addition to healthcare workers, patients in healthcare settings are also at significant risk for infection. In the United States, annually approximately 2 million patients acquire nosocomial infections, at a treatment cost exceeding $4.5 billion (Bures, et al, 2000).
In the US, the reporting of diseases is mandated by state laws and regulations. These laws and regulations, as to which infectious diseases are reportable, vary from state to state. The National Nosocomial Infections Surveillance (NNIS) System is a cooperative effort that began in 1970 between the Centers for Disease Control and Prevention (CDC) and participating hospitals to create a national nosocomial infections database. The database is used to:
- Describe the epidemiology of nosocomial infections
- Describe antimicrobial resistance trends
- Produce nosocomial infection rates to use for comparison purposes.
The data are collected uniformly by trained infection control personnel using surveillance protocols that target inpatients at high risk of infection and are reported routinely to CDC where they are aggregated into the database. Participation in the NNIS System is voluntary and involves only acute care general hospitals in the United States. Long term care facilities, such as rehabilitation, mental health, and nursing homes are not included in the NNIS System. By law, CDC assures participating hospitals that any information that would permit identification of any individual or institution will be held in strict confidence. Application of Controls to Reduce or Eliminate Hazards Related to Tuberculosis (TB)
The use of both engineering controls and work practice controls can help to reduce or eliminate the spread of TB. Engineering controls include the use of isolation rooms that provide 6 exchanges per hour. Portable ventilators should be used if appropriate rooms are not available. Negative pressure is needed; keep the patient room door closed. Verify air exchange rate and negative pressure regularly.
NIOSH approved HEPA filter respirators should be worn whenever:
- Entering rooms of patients with suspected or confirmed TB.
- Performing high hazard procedures in patients with suspected or confirmed TB, such as aerosolized medication administration, bronchoscopy, or sputum induction.
- Transporting patient with suspected or confirmed TB in a closed vehicle, even if the patient is wearing a mask.
The use of ultra violet light is an adjunct to other measures. Work practice controls include the following:
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