Lowering the Risk

Despite safeguards, occupational blood exposure continues to occur and needs
to be viewed as an urgent health issue.
by Judith Green-McKenzie and Marilyn Watkins


Exposure to bloodborne pathogens (BBPs) is an occupational hazard for many
workers, including, among others, health care workers, law enforcement
officers, fire service personnel, funeral service employees, body piercers,
day care workers, environmental service workers, and wastewater workers.
BBPs are microorganisms present in human blood that can potentially cause
disease in humans.1 The BBPs of main concern are human immunodeficiency
virus (HIV), Hepatitis B virus (HBV), and Hepatitis C virus (HCV).

Exposure to blood presents the highest risk for the transmission of BBPs in
the occupational setting.2 HIV causes the acquired immunodeficiency
syndrome. Both HBV and HCV can cause chronic hepatitis, cirrhosis, liver
cancer, and liver failure.

Occupational Exposure
An occupational exposure occurs when a worker experiences a percutaneous
injury, mucous membrane contact, or skin contact with potentially infected
blood or body fluid. The percutaneous injury may be from a needle or other
sharp object. Mucous membrane contact may occur after a splash to the eyes,
nose, mouth, or throat. Skin that is abraded or otherwise compromised due to
a cut, rash, or break can assist transmission by providing a portal of
entry.

Not all body fluids are considered potentially infectious. Body fluids
containing visible blood, semen, and vaginal secretions are considered
potentially infectious fluids, as are fluids from around the lungs, heart,
and abdominal wall. Concentrated virus in a research lab is also considered
potentially infectious. However, sweat, tears, nasal secretions, saliva,
sputum, vomit, urine, and feces are not considered infectious unless blood
is present in these fluids.3

It is estimated that the risk of developing HIV infection after experiencing
a percutaneous injury with an HIV contaminated needle is 0.3 percent. The
risk of being infected with HBV after a percutaneous injury if the needle
has blood contaminated with HBV is 27 percent to 37 percent, and the risk is
1.8 percent if the needle has blood contaminated with HCV.

If the exposure to contaminated blood is via the mucous membranes, the risk
of developing HIV infection is 0.09 percent. The risk from exposure of
non-intact skin to contaminated blood is unclear but less than the risk from
mucous membrane exposure. The risk from a bite has not been quantified;
however, both the victim and the biter need to be evaluated by a health care
provider who can then assess the risk and decide on treatment.3,4

Formal Efforts to Reduce Exposure
Various strategies designed to reduce the risk of occupational exposure to
BBPs have been recommended and implemented during the past three decades.
Much of what has been written has concerned health care personnel. However,
the same exposure and management principles can be applied to other
workers.3


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Formal efforts to help prevent transmission of the HIV virus in the health
care setting started in the early 1980s.
Formal efforts to help prevent transmission of the HIV virus in the health
care setting started in the early 1980s when the Centers for Disease Control
and Prevention recommended the use of Universal Precautions (UP). The
underlying premise of UP is that all blood and body fluids should be treated
as if they are potentially infectious for HIV, HBV, HCV, and other BBPs.
Work practices consistent with UP include the use of personal protective
barrier equipment, such as gloves, masks, gowns, and protective eyewear,
when there is a potential for exposure to blood and body fluids. Masks and
protective eyewear should reduce the incidence of contamination of mucous
membranes of the nose, mouth, and eyes. Other elements of UP are that sharp
objects should be disposed of in puncture-resistant containers, needles and
other sharp instruments should be used with caution, and needles should not
be recapped.5

These CDC recommendations were updated in 1987, and in 1991 the Occupational
Safety and Health Administration promulgated the Bloodborne Pathogens
Standard with the intent to help prevent BBP exposures in the workplace.
This standard, which covers all workers with recognized risk of exposure to
BBPs, went into effect a few months later, requiring employers to establish
an exposure plan designed to eliminate or minimize employee exposure to
BBPs; to be responsible for educating and training exposed workers on BBPs;
to provide accessible engineering controls such as sharps disposal
containers to employees; and to provide accessible personal protective
equipment, such as gloves, gowns, and pocket masks in order to eliminate or
minimize employee exposure. Under the standard, employers also are required
to maintain a clean workplace and adequately communicate hazards, such as
potentially infectious waste, to employees. UP is an important part of the
standard.1,6

In an effort to further decrease needlesticks and other sharps injuries,
OSHA revised the BBP standard in 2001 with the intent to help ensure
implementation of new developments in safe needle technology. The revised
standard requires employers to select safer needle devices as they become
available and to involve employees in identifying and choosing the devices.3
The introduction of sharps, such as needles and intravenous catheters, that
possess safety engineered features (engineered sharps injury prevention
devices) has been shown to lead to a decrease in percutaneous injuries.7,8

Medical Intervention After an Exposure
The standard requires that employers provide confidential medical
post-exposure evaluation and follow-up for workers with occupational
exposure to BBPs who are covered by the standard. Under the standard,
employers must provide the HBV vaccine to all employees at risk for exposure
to HBV.1 But even when the HBV vaccine is made available, not all eligible
workers choose to be vaccinated.9 As such, many workers remain unprotected
from HBV.


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Post-exposure prophylaxis (PEP) is available to HBV-exposed workers who are
not immune to HBV.
Post-exposure prophylaxis (PEP) is available to HBV-exposed workers who are
not immune to HBV, in the form of HBV vaccine and hepatitis B immune
globulin (HBIG). HBIG is 75 percent effective in protecting against HBV
infection, and serious adverse side effects are rare when it is administered
appropriately. It is best to give PEP for HBV as soon as possible after
exposure because the effectiveness of HBIG seven days post-exposure is not
known.3

There is no cure or effective vaccine for Acquired Immune Deficiency
Syndrome, but PEP in the form of HIV antiretroviral drugs given soon after
occupational exposure decreases the risk of infection. In the event of an
exposure, medical treatment and follow-up should be sought immediately so
that PEP can be administered timely. PEP for HIV given 24 to 36 hours after
infection is less effective than if it is given sooner. There is no vaccine
or PEP available for HCV, although treatment with interferon soon after HCV
transmission to an exposed worker is associated with a higher rate of
resolved infection than if no treatment was given.1,3,4

An Urgent Health Issue
In summary, workers from several occupations are at risk of exposure to BBPs
during the course of their work. Prevention of occupational blood exposure
is the primary way to prevent transmission of BBPs, and efforts made in
recent decades to prevent and reduce such potential exposure have met with
some success.3 This includes universal precautions; promulgation of the BBP
standard, which requires engineering and work practice controls; PPE and the
provision of post-exposure evaluation and follow-up; and, most recently,
revision of the BBP standard requiring the use of engineered sharps injury
prevention devices.,P> Despite these safeguards, BBP exposures continue to
occur and need to be viewed as an urgent health issue. Hospital protocols
need to promote expeditious treatment of these exposures.

Health care workers familiar with post-exposure treatment and follow-up
after a BBP exposure should be available to workers with the potential for
occupational BBP exposures. Local experts and national resources such as the
national clinicians hotline (888-448-4911) can be consulted.4 Knowledge of
how to access appropriate medical care in a timely manner in the event of an
exposure can decrease the chances of an individual acquiring a
life-threatening infection while at work.


References
1. United States Department of Labor, Occupational Safety and Health
Administration. Occupational Exposure to Blood-borne pathogens--Final Rule.
29CFR Section 1910.1030. Fed Register. Dec. 6, 1991.
2. Centers for Disease Control and Prevention. "Guidelines for prevention of
transmission of human immunodeficiency virus and hepatitis virus to
healthcare and public safety workers. A response to P.L. 100-607. The Health
Omnibus Programs Extension Act of 1988." MMWR. 1989; 38(5-7): 3-37.
3. "Updated U.S. Public Health Service guidelines for the management of
occupational exposures to HBV, HCV, and HIV and recommendations for
postexposure prophylaxis." MMWR. 2001; 50(RR-11): 1-52.
4. Gerberding JL. "Occupational Exposure to HIV in Health Care Settings." N
Engl J Med. 2003; 348: 826-844.
5. Centers for Disease Control. "Recommendations for preventing transmission
of infection with human T-lymphotropic virus type
III/lymphadenopathy-associated virus in the workplace." MMWR 1985; 34:
681-686, 691-695.
6. Centers for Disease Control. "Recommendations for prevention of HIV
transmission in health-care settings." MMWR 1987; 36: 1S-18S.
7. Perry J, Parker G, Jagger J. "EPINet Report: 2001 Percutaneous Injury
Rates." Advances in Exposure Prevention. 2003; 6: 32-37.
8. Mendelson MH, Bao YL, Solomon R, et. al. "Evaluation of a Safety
Resheathable Wing Steel Needle for prevention of percutaneous injuries
associated with Intravascular-Access procedures among Health Care Workers."
Infect Control Hosp Epidemiol. 2003; 24: 105-112.
9. Behrman AJ, Shofer F, Green-McKenzie J. "Trends in bloodborne pathogen
exposure and follow-up at an urban teaching hospital:1987 to 1997." J Occup
Environ Med. 2001; 43: 370-376.

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This article appeared in the April 2005 issue of Occupational Health &
Safety.