Q. How serious is the occupational risk of needlestick injuries to health care workers?
A. One of the most critical control components of health care worker protection against bloodborne pathogens must be the reduction of sharps-related incidents. The statistics cited below provide a picture of the seriousness of the problem.
Hospital-based health care workers experience some 800,000 needlestick injuries each year in the United States (Jagger,1990). About 2% or approximately 16,000 of these are likely to be contaminated by HIV (American Hospital Association, 1992). Needlestick injuries account for up to 80% of all accidental exposures to blood. (Jagger, 1988).
Based on various studies, researchers have documented that needlestick injuries are under reported by health care workers and the number of exposures could potentially be much higher (Hamory, 1983). Chiarello (1992) cites several studies that found rates of under-reporting between 40.4% and 53% for nurses and 92% for laboratory personnel. Physicians under reported needlestick injuries by 70% to 95%.
In well-documented studies, injuries from contaminated needles and other sharp devices used in the health care setting have been associated with transmission of bloodborne pathogens to health care workers. In fact, more than 20 pathogens have been transmitted through sharps or needlestick injuries (Chiarello, 1992). Of these, HIV, HBV and HCV pose the greatest risk to the health care worker (Ippolito et al., 1997). The risk of transmission of HBV and HCV through percutaneous injury is much higher than for HIV (CDC, 1991).
Understanding the prevalence of these bloodborne diseases in the patient population gives a better picture of the risk health care workers face:
A study of the Johns Hopkins Hospital emergency room determined the prevalence of the HCV, HBV and HIV in blood samples from 2523 patients. Of those patients:
18% were seropositive for HCV
5% were seropositive for HBV
6% were seropositive for HIV (Kalen et al, 1997).
An estimated 1.25 million people in the U.S. are chronically infected with HBV and 6,000 die each year as a result of HBV-related liver disease (Moyer & Hodgson, 1996).
In 1989, the CDC studied the prevalence of HIV in three inner-city hospitals and three suburban hospitals. In the three inner-city hospitals, seroprevalence of HIV ranged from 4.1 to 8.9 per 100 patients. The suburban hospitals' seroprevalence rates ranged from 0.2 to 6.1 per 100 patients. (Marcus et al., 1989)
In 1997, the National Institutes of Health estimated that nearly 4 million people in the U.S. are infected with Hepatitis C (NIH, 1997). Of these, 85% develop chronic HCV infection and the potential for transmission of HCV to others (CDC, 1997).
Q. What occupational risk does Hepatitis B pose to the health care worker?
A. For more than 50 years, HBV infection, a well-documented and recognized occupational hazard, has been and continues to be one of the most common bloodborne pathogens among health care workers. Studies conducted prior to implementation of recommendations to prevent bloodborne pathogen transmission (1976-1985) show that health care workers had a prevalence of HBV infection three to five times higher than the general U.S. population (Moyer & Hodgson, 1996).
Hepatitis B is much more transmissible than HIV. Health care workers at greatest risk work in areas where they are directly exposed to blood ( in emergency rooms, clinical laboratories, operating rooms, hemodialysis units, etc.) (CDC, 1991).
The risk of a health care worker contracting HBV from needlestick injuries ranges from 6% to 30% (CDC, 1991).
In 1994, 1000 health care workers developed HBV infection, and each year 100 to 200 health care workers die from this disease (CDC, 1997). The Centers for Disease Control and Prevention (CDC) estimates that the annual number of new HBV infections in health care workers has steadily declined from 12,000 in 1985, due in part to the widespread adoption of universal precautions, vaccination against hepatitis B, and the implementation of OSHA's Bloodborne Pathogens Standard. (Moyer & Hodgson, 1996).
Q. What occupational risk does Hepatitis C pose to the health care worker?
A. Hepatitis C virus infection is a major cause of chronic liver disease in the United States and worldwide. The virus, because of its similarity to HBV, presents an occupational risk to persons whose work activities involve handling human blood and body fluids (CDC, 1997).
Needlestick injuries are the most common cause of occupational HCV exposure (Hibberd, 1995).
In 1995, an estimated 560 to 1,120 cases of HCV infection occurred among health care workers who were occupationally exposed to blood (Alter, 1993).
No vaccine is available for hepatitis C and no effective post-exposure prophylaxis is known at this time (CDC, 1997).
Screening tests for hepatitis C antibodies are commercially available, but interpretation of the results, especially in a post-exposure situation, is limited by several factors.
A positive result does not distinguish between acute, chronic, or past infection, and a negative result does not indicate the absence of acute infection, only the absence of antibodies to HCV.
False positives are common in populations with a low prevalence of HCV.
The tests do not detect HCV antibodies in approximately 5% of people (CDC, 1997).
As many as 85% of all HCV-infected persons develop chronic infection. Persons with chronic hepatitis are at increased risk for cirrhosis and primary hepatocellular carcinoma. Hepatitis C is now the leading reason for liver transplantation in the United States. (NIH, 1997).
Q. What occupational risk does HIV pose for the health care worker?
A. HIV infection has been reported after occupational exposures to HIV-infected blood through needlesticks or cuts; splashes in the eyes, nose, or mouth; and skin contact.
Exposures from needlesticks or cuts cause most infections. The average risk of HIV infection after a needlestick exposure to HIV-infected blood is 0.3% or 1 in 300. Even though the risk of seroconversion after needlestick is relatively rare, injured health care workers may suffer disabling physical side effects from post-exposure anti-viral medication as well as severe emotional trauma as they await their test results (CDC, 1991).
The risk after exposure of the eye, nose, or mouth to HIV-infected blood is estimated to be, on the average, 0.1% or 1 in 1,000 (CDC, 1987).
The risk after exposure of the skin to HIV-infected blood is estimated to be less then 0.1%. The risk may be higher if the skin is broken or if the contact involves a large area of skin or is prolonged (CDC, 1987).
As of December 1998, CDC had received reports of 54 documented cases and 134 "possible" cases (i.e., documentation was unclear) of occupationally acquired HIV among health care workers in the United States. Of the 54 documented cases of occupationally acquired HIV infection, 46 resulted from needle sticks or cuts (CDC HIV/AIDS Surveillance Report, 1998) (Table 2). The total number of occupationally acquired HIV infections in health care workers is increasing each year (Figure 3).
Table 2
Health Care Workers with Documented and Possible Occupationally Acquired AIDS/HIV Infection, by Occupation, Reported through December 1998, United States(1)
(Source: CDC, HIV/AIDS Surveillance Report, 1998; vol.10 (no.2), table 17)
(1) Health care workers are defined as those persons, (including students and trainees), having worked in a health care, clinical, or HIV lab setting at any time since 1978.
(2) Health care workers who had a documented HIV seroconversion after occupational exposure or had other laboratory evidence of occupational infection: 46 had percutaneous exposures, 5 had mucocutaneous exposures, 2 had both percutaneous and mucocutaneous exposures, and 1 had an unknown route of exposure. Forty-nine exposures were to blood from an HIV-infected person, 1 to visibly bloody fluid, 1 to an unspecified fluid, and 3 to concentrated virus in a laboratory. Twenty-four of these health care workers developed AIDS.
(3) Health care workers in this category have been investigated and are without identifiable behavioral or transfusion risks; each reported percutaneous or mucocutaneous occupational exposures to blood or body fluids, or laboratory solutions containing HIV, but HIV seroconversion specifically resulting from an occupational exposure was not documented.
(4) Technician/therapist-other than respiratory therapists, dialysis technicians, and surgical technicians.
Figure 3
Health Care Workers with Occupationally Acquired AIDS/HIV Infection Cumulative Cases, 1987 through 1996
Sources: Morbidity and Mortality Weekly Report (1987-1988) and the HIV/AIDS Surveillance Report (1992-1995), Centers for Disease Control and Prevention.
Note: The CDC did not publish statistics on occupationally acquired HIV in health care workers in the years 1989, 1990, and 1991. The CDC began publishing statistics on health care workers with possible occupationally acquired HIV in 1992.
Q. Why are universal precautions and personal protective equipment not adequate to protect the health care worker against needlestick injuries?
A. Using universal precautions, along with personal protective equipment, engineering controls and other work practice controls, reduces employee exposure to bloodborne pathogens. Personal protective equipment provides a barrier to protect skin and mucous membranes from contact with blood and other potentially infectious material (OPIM), but most personal protective equipment is easily penetrated by needles. Needlestick injuries are caused by unsafe needle devices rather than careless use by health care workers. (Jagger, 1988). Safer needle devices have been shown to significantly reduce the incidence of accidental needlesticks and exposure to potentially fatal bloodborne illnesses (CDC, 1997).
A. A safer needle device incorporates engineering controls to prevent needlestick injuries before, during, or after use through built-in safety features. The term, "safer needle device," is broad and includes many different types of devices from those that have a protective shield over the needle to those that do not use needles at all. The common feature of effective safer needle devices is that they reduce the risk of needlestick injuries for health care workers.
E-Mail
Printable Single-Page
Glossary
Share
