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Preventing transmission of blood-borne pathogens: A compelling argument for effective device-selection strategies
Preventing transmission of blood-borne pathogens: A compelling argument for effective device.selection strategies Jeanne Culver, RN, BSN, COHN Atlanta, Georgia Disease transmission from percutaneous injury occurs in 2% to 40% of health care workers (HCWs) after exposure to the hepatitis B virus (HBV), in 3% to 10% after exposure to the hepatitis C (HCV) virus, and in 0.2% to 0.5% after exposure to the HIV virus. According to a recently published case-control study from the Centers for Disease Control and Prevention, the following factors increase the risk of HIV seroconversion in HCWs after percutaneous exposure to HIV-infected blood: deep injury, visible blood on the device, procedures involving needle placement directly into a vein or artery, and terminal AIDS in the source patient. Postexposure use of zidovudine by HCWs appears to reduce the risk of HIV transmission by 79%. Institutions seeking to reduce the risk of HCW seroconversion should conduct analyses of specific tasks associated with these high-risk factors, and safety interventions should be installed when tasks and devices increase the risk of seroconversion. Although this type of outcome-based strategy may not significantly reduce the total number of needlestick injuries, reducing high-risk exposures minimizes disease transmission and maximizes the costeffectiveness of the intervention. (AJIC Am J Infect Control 1997;25:430-3) Several a u t h o r s h a v e p u b l i s h e d articles o n n e e d l e s t i c k p r e v e n t i o n , m a n a g e m e n t of e x p o s u r e s to blood, a n d c o s t a n a l y s e s of b o t h n e e d l e s t i c k - p r e v e n t i o n devices a n d p o s t e x p o s u r e m a n a g e m e n t . l . 2 T h e c o n n e c t i o n b e t w e e n e x p o s u r e to b l o o d - b o r n e p a t h o g e n s a n d h e a l t h c a r e w o r k e r ( H C W ) seroc o n v e r s i o n w a s e s t a b l i s h e d b y G e r b e r d i n g ' s res e a r c h in 1995; it c o n c l u d e d t h a t p e r c u t a n e o u s injuries are t h e k i n d s o f injuries m o s t o f t e n associa t e d w i t h t r a n s m i t t i n g b l o o d - b o r n e d i s e a s e s to HCWs. 1 A recent retrospective case-control study published b y the C e n t e r s f o r D i s e a s e C o n t r o l a n d P r e v e n t i o n (CDC) d e t e r m i n e d t h a t h o l l o w - b o r e n e e d l e s u s e d d u r i n g v e n o u s a c c e s s p r o c e d u r e s acc o u n t e d f o r 29 of 31 (94%) H e w s e r o c o n v e r sions. 3 T h e s e f i n d i n g s a r e p a r t i c u l a r l y i m p o r t a n t b e c a u s e the t r e n d is to a l l o w n o n p h l e b o t o m y pers o n n e l to p e r f o r m v e n o u s a c c e s s p r o c e d u r e s .
From Employee Occupational Health Services, Emory University Hospital. Reprint requests: Jeanne Culver, RN, BSN, COHN, Manager, Employee Occupational Health Services, Emory University Hospital, Room HB53, 1364 Clifton Rd. NE, Atlanta, GA 30322. Copyright © 1997 by the Association for Professionals in Infection Control and Epidemiology, Inc. 0196-6553/97 $5.00 + 0 17/49/80418
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I f i n s t i t u t i o n - b a s e d risk a n a l y s i s is i n c o r p o r a t e d into p u r c h a s i n g decisions, devices d e s i g n e d to inc r e a s e safety will b e u s e d a n d h i g h - r i s k b l o o d exp o s u r e s will b e r e d u c e d . D i s c u s s i o n of the role of a n t i r e t r o v i r a l p o s t e x p o s u r e p r o p h y l a x i s in r e d u c ing s e r o c o n v e r s i o n a f t e r H I V - p o s i t i v e b l o o d expos u r e is b e y o n d the s c o p e of this article. Rather, this r e v i e w f o c u s e s o n e x p o s u r e - r e l a t e d f a c t o r s as a b a s i s f o r b l o o d e x p o s u r e p r e v e n t i o n a n d cost-effective p u r c h a s i n g strategies.
BACKGROUND T h e a c t u a l n u m b e r o f n e e d l e s t i c k s t h a t o c c u r is difficult to e s t i m a t e b e c a u s e as m a n y as 70% m a y go u n r e p o r t e d b y H C W s ? I n j u r i e s involving a n infectious source patient carry varying degrees of risk of infection, d e p e n d i n g o n the p a t h o g e n . Dise a s e t r a n s m i s s i o n will o c c u r in 2% to 40% of H C W s a f t e r h e p a t i t i s B v i r u s (HBV) e x p o s u r e , in 3% to 10% a f t e r h e p a t i t i s C v i r u s (HCV) e x p o s u r e , a n d in 0.2% to 0.5% a f t e r H I V e x p o s u r e (Table 1). 1 F o r all t h r e e diseases, h i g h r a t e s o f m o r b i d i t y , h u m a n suffering, a n d mortality, a n d i n c r e a s e d h e a l t h c a r e costs are a s s o c i a t e d w i t h s e r o c o n v e r s i o n . H B V i n f e c t i o n is the o n l y o c c u p a t i o n a l l y acquired, b l o o d - b o r n e i n f e c t i o n t h a t is v a c c i n e preventable. However, successful postexposure prop h y l a x i s is d e p e n d e n t o n t h e s o u r c e ' s infectivity s t a t u s a n d the t i m e l i n e s s of the p r o p h y l a c t i c treat-
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T a b l e 1. Risk assessment after occupational exposure to blood-borne pathogens 1 Risk of transmission
Virus
Percutanaous injury*
Mucosal contact or contact with injured (broken) skint
HBV
2-40%
HCV
3-10%
HIV
0.2-0.5%
Not quantified (transmission by this route has been documented; the magnitude of risk is probably high relative to that for HCV and HIV) Not quantified (transmission by this route has not been documented but is plausible) Not quantified (transmission by this route has been documented; pooled risk estimate, 0.1%)
Infectious material
Bite wound~:
Documented
Not quantified (transmission by this route has been documented)
Blood, blood products
Semen, vaginal fluid, bloody fluids, saliva
Urine, feces
Not quantified (transmission by this route has not been documented)
Blood
Blood products, bloody fluids, semen, vaginal fluid
Saliva, urine, feces
Not quantified (possible route of transmission in 2 cases of nonoccupational exposure)
Blood, blood products, bloody fluids
Semen, vaginal fluid, cerebrospinal fluid, breast milk, exudates, seresal fluids, amniotic fluid, saliva (during dental procedures)
Saliva, urine, feces
Possible§
Unlikely
Modified from Gerberding JL. Management of occupational exposures to blood-borne viruses. N Engl J Med 1995;332:444-51. Reprinted by permission of The New England Journal of Medicine, copyright 1995, Massachusetts Medical Society. *The risk estimates are based on pooled data evaluating percutaneous exposures to blood through needle punctures and other injuries inflicted by contaminated sharp objects. 1-Contact with intact skin is not a proved route of transmission of blood-borne viruses. However, small breaks in the skin may escape detection, and many experts consider contact with skin a potential route of transmission, especially when the surface area is large or the duration of contact is prolonged. SThe person inflicting the bite may be at risk for mucosal contact with bIood if the bite causes bleeding. {}These fluids have not yet been implicated in occupational transmission but are considered potential sources because they are likely to contain virus or have been implicated in other modes of transmission.
ment. 1 Because vaccines are not available for HCV or HIV, institutions wishing to provide a safer work environment should make it a priority to use needle devices that can prevent the HCW from coming into contact with potentially infectious blood on the tip of a needle. Other investigators have linked drawing venous blood with a higher rate of HIV transmission. Berry reported, "A greater frequency of needles used to draw venous blood was represented in the group of HCWs with documented seroconversion than in the group with reported needlestick injuries (50% vs 20%, p = 0.0002). "s This comparative analysis also did not find an association between injuries caused by needles used to connect intravenous (IV) lines and H W seroconversion (p = 0.013). s McCormick's study showed a high incidence rate of sharps injuries a m o n g phlebotomists (407/1000 employees per year) despite a low frequency rate of exposure (1/26,871 draws). 6 Technical expertise appears to be a factor in the low exposure frequency; however, a high rate of HIV seroconversion among phlebotomists has been reported. 7 NEW DATA
A recently published international case-control study of HIV seroconversion in HCWs after per-
cutaneous exposures to HIV-infected blood analyzed the risk factors associated with HIV transmission. 3 This retrospective study was conducted by the CDC in collaboration with French and British public health authorities. The case study population (n = 31) included 23 HCWs in the United States, 5 in France, and 3 in the United Kingdom. All the HCWs had a documented occupational percutaneous exposure to HIV-infected blood between January 1988 and August 1994 resulting in seroconversion. The control group of HCWs (n -- 679) had documented percutaneous exposure to HIV-infected blood, but were HIV seronegative 6 months after exposure. Analysis included demographic information about the exposure, stage of HIV infection in the source patient, and exposure-related information. 3 Two factors had an important effect on increasing seroconversion rates after percutaneous exposure to HIV-infected blood. These are (1) exposure to a large quantity of blood, defined as a procedure where a needle is placed directly into a vein or artery; a deep puncture, with or without bleeding; or a device visibly contaminated with the source patient's blood; or (2) exposure to blood from a source patient with terminal AIDS. 3 A third important factor was the postexposure use of zidovudine, which reduced the seroconver-
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sion rate by approximately 79%. The exposure variables related to seroconversion are most relevant to the identification of devices and procedures that put HCWs at greatest risk for disease transmission after percutaneous injury. Hence, venous access procedures pose the greatest occupational risk for HIV transmission. The results of this study further indicate the need for risk-based purchasing strategies for products that directly reduce this hazard. RISK ANALYSIS
Each institution has a unique risk profile based on treatment, facility, and staff variables. The necessary data can be gathered through a simple postinjury questionnaire that is completed at the time a needlestick is reported, s Experts agree that data collected should include the job classification of the injured HCW, type and size of needle used, location of the incident, the specific procedure performed, and other environmental details, a,9 Data analysis should focus on outcome measures, including injuries associated with highrisk tasks and related seroconversions. IMPLICATIONS FOR P U R C H A S I N G S T R A T E G Y
The CDC data confirming that specific tasks are associated with seroconversion should influence purchasing strategy. 3 Often, an institution's safetyrelated purchasing strategy is directed at outcomes, such as reducing the total annual n u m b e r of needlesticks. For example, needleless IV systems will effectively reduce the n u m b e r of needlesticks associated with IV manipulation, including punctures from piggyback needles, flushing heparin locks, aspiration from IV ports, or injecting medication into IV lines, a° However, this strategy is not likely to reduce disease transmission because needlesticks related to these tasks are not positively associated with seroconversion, s,l° Hence, such a strategy becomes a cost-intensive effort that has no apparent impact on reducing costly negative outcomes. Rather, risk prevention strategies should t a r g e t tasks and devices that involve large volumes of blood, the placement of a device in a vein or artery, or have the potential for deep injury. 3 Although such a strategy m a y not significantly reduce the total n u m b e r of needlestick injuries, avoiding this kind of exposure minimizes the risk of seroconversion among those HCWs at highest risk. 1 A study reported by Jagger, which related needlesticks to the device used, concluded that HCW exposure to blood during phlebotomy pro-
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cedures could be reduced if needle devices were redesigned so that HCWs' hands always remained behind the needle. 11 Therefore, hazard elimination should be the first consideration in the institution's risk analysis. Can the sharp device be eliminated by using a different product or procedure? If not, what devices are available to protect the needle during or after use? 9 Product selection criteria should include design and performance elements that would balance clinical patient care needs with safety needs. Specifically, choices must be made between a "passive" device, one that requires no action by the HCW, and an "active" device, one that requires the HCW to engage the safety feature. 9 Consideration must also be given to the training and education required to ensure adoption of and compliance with engineering controls. 12 P R O D U C T SELECTION
The product evaluation and selection process should be based on the institution's data-driven risk analysis, product substitution, and cost factors. Ideally, safety product selection should involve a multidisciplinary group, reflecting the breadth of an institution's interests, expertise, and user population. The model safety products evaluation team that Chiarello suggested included representatives from administration, infection control, employee health, materials management, waste management, clinical staff, central supply, risk management, industrial hygiene, and labor, when appropriate. 9 The product evaluation team approach supports an institution's need to establish priorities and focus intervention efforts in a cost-effective manner. It seems that innovative technology has inundated the marketplace in response to the need to reduce HCW exposure to blood-borne pathogens. These entrepreneurial efforts have eclipsed the purchaser's ability to objectively determine a product's efficacy, safety, and cost, which m a y be as m u c h as 20 times the cost of conventional devices. 1° Therefore, a rigorous product evaluation process is mandatory to objectively determine the value of any safety initiative. Selecting a subset of the user population to try products and provide feedback to the safety product evaluation team is an essential part of the process. 9 User acceptance of the new product is critical to the success of the safety intervention, and ultimately to the cost-effectiveness of the device, because haphazard use m a y negate the potential benefit. 8 Thus, for a product to be consid-
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e r e d cost-effective, it m u s t r e d u c e the total n u m b e r of h i g h - r i s k e x p o s u r e s a n d a s s o c i a t e d m o r b i d ity, a n d it m u s t e n g e n d e r a h i g h d e g r e e of u s e r c o m p l i a n c e . 1° CONCLUSION
I n m a n y institutions, a t t e n t i o n h a s b e e n f o c u s e d o n p r e v e n t i n g as m a n y n e e d l e s t i c k s as possible. H o w e v e r , e v e n if it w e r e p o s s i b l e to a c h i e v e this in a cost-effective m a n n e r , c u r r e n t r e s e a r c h s h o w s t h a t this s t r a t e g y w o u l d n o t a c h i e v e t h e u l t i m a t e goal: p r e v e n t i n g s e r o c o n v e r s i o n s . 1° T h u s , r e c e n t r e s e a r c h linking s e r o c o n v e r s i o n w i t h e x p o s u r e to a l a r g e v o l u m e of b l o o d m a k e s a c o m p e l l i n g a r g u m e n t f o r safety initiatives a n d p u r c h a s i n g strategies t h a t f o c u s o n h i g h - r i s k p r o c e d u r e s , e s p e c i a l l y t h o s e involving v e n o u s o r a r t e r i a l access. Poste x p o s u r e s u r v e i l l a n c e a n d t r e a t m e n t of H C W s w h o h a v e s i g n i f i c a n t e x p o s u r e s to b l o o d a r e costly a n d labor-intensive processes, with serious physical and emotional consequences for HCWs. T h e u l t i m a t e goal of r i s k m a n a g e m e n t , infect i o n control, a n d o c c u p a t i o n a l h e a l t h a n d safety p r o v i d e r s is p r e v e n t i n g t h e t r a n s m i s s i o n of disease. P r e v e n t i o n , t h e r e f o r e , m u s t i n c l u d e a p r o a c tive a p p r o a c h to r i s k r e d u c t i o n t h a t i n c l u d e s a v o i d a n c e of e x p o s u r e s t h r o u g h t a r g e t e d s a f e t y interventions, aggressive HBV immunization prog r a m s , a n d effective p o s t e x p o s u r e m a n a g e m e n t w h e n e x p o s u r e s occur. This r e v i e w i n d i c a t e s t h a t efforts to r e d u c e the i n c i d e n c e of s e r o c o n v e r s i o n a f t e r p e r c u t a n e o u s i n j u r y s h o u l d f o c u s o n s a f e r n e e d l e devices for v e n o u s access p r o c e d u r e s . S i m u l t a n e o u s i m p l e m e n t a t i o n of c o m p e t e n c y - b a s e d t r a i n i n g f o r phleb o t o m y tasks, i m p r o v e d i n j u r y - r e p o r t i n g m e c h a n i s m s , a n d p r o m p t a c c e s s to c o n f i d e n t i a l a n d c o m p e t e n t p o s t e x p o s u r e m a n a g e m e n t , a r e also critical to t h e s u c c e s s of safety initiatives. 1,9,12-14At a time when health care institutions are implem e n t i n g c r o s s - f u n c t i o n a l t r a i n i n g of n o n p h l e b o t o m y p e r s o n n e l to p e r f o r m v e n o u s a c c e s s p r o c e dures, b o t h in a n d o u t of t r a d i t i o n a l h e a l t h c a r e e n v i r o n m e n t s , the n e e d f o r c o m p e t e n c y - b a s e d t r a i n i n g in t h e u s e of v e n o u s access devices is imperative. 6 T h e safest device in the h a n d s of a n u n -
skilled u s e r u n d e r m i n e s a n institution's b e s t efforts to c o n t r o l costs a n d r e d u c e injuries. A comprehensive hazard surveillance system t h a t m e a s u r e s the severity of the risk, c o u p l e d w i t h a n effective s a f e t y p r o d u c t e v a l u a t i o n t e a m , will p r o v i d e i n s t i t u t i o n s w i t h the n e c e s s a r y inform a t i o n f o r cost-effective, r i s k - t a r g e t e d safety initiatives. REFERENCES 1. Gerberding JL. M a n a g e m e n t of occupational exposures to blood-borne viruses. N Engl J Med 1995;332:444-51.
2. Laufer FN, Chiarello LA. Application of costeffectiveness methodology to the consideration of needlestick-prevention technology. Am J Infect Control 1994;22:75-82. 3. Centers for Disease Control and Prevention. Case control study of HIV seroconversion in health-care workers after percutaneous exposure to HIV-infected blood--France, United Kingdom, and United States, January 1988-August 1994. MMWR 1995;44:929. 4. Mangione CM, Gerberding JL, Cummings SR. Occupational exposure to HIV: frequency and rates of underreporting of percutaneous and mucocutaneous exposures by medical housestaff. Am J Med 1991;90:85-90. 5. Berry AJ. Are some types of needles more likely to transmit HIV to health care workers? Am J Infect Control 1993; 21:216-7. 6. McCormick RD, Meisch MG, Ircink FG, Maki DG. Epidemiology of hospital sharps injuries: a 14-year prospective study in the pre-AIDS and AIDS eras. Am J Med 1991; 91(suppl 3B):301S-7S. 7. Jagger J. Risky procedures, risky devices, risky job. Advances in Exposure Prevention 1994; 1:4-9. 8. Wugofski L. Needlestick prevention devices: a pointed discussion. Infect Control Hosp Epidemiol 1992;13:295-8. 9. Chiarello LA. Selection of needlestick prevention devices: a conceptual framework for approaching product evaluation. Am J Infect Control 1995;23:386-95. i0. Orenstein R, Reynolds L, Karabaic M, Lamb A, Markowitz SM, Wong ES. Do protective devices prevent needlestick injuries among health care workers? Am J Infect Control 1995;23:344-51. 11. Jagger J, Hunt EH, Brand-Elnaggar J, Pearson RD. Rates of needlestick injury caused by various devices in a university hospital. N Engl J Med 1988;319:284-8. 12. Murphy D. The development of a risk management program in response to the spread of bloodborne pathogen illnesses. J Intraven Nurs 1995;18:$43-$7. 13. Update: Provisional Public Health Service recommendations for chemoprophylaxis after occupational exposure to HIV. MMWR 1996;45:468. 14. Gerberding JL. Prophylaxis for occupational exposure to HIV. Ann Intern Med 1996;125:497-501.
From Employee Occupational Health Services, Emory University Hospital. Reprint requests: Jeanne Culver, RN, BSN, COHN, Manager, Employee Occupational Health Services, Emory University Hospital, Room HB53, 1364 Clifton Rd. NE, Atlanta, GA 30322. Copyright © 1997 by the Association for Professionals in Infection Control and Epidemiology, Inc. 0196-6553/97 $5.00 + 0 17/49/80418
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I f i n s t i t u t i o n - b a s e d risk a n a l y s i s is i n c o r p o r a t e d into p u r c h a s i n g decisions, devices d e s i g n e d to inc r e a s e safety will b e u s e d a n d h i g h - r i s k b l o o d exp o s u r e s will b e r e d u c e d . D i s c u s s i o n of the role of a n t i r e t r o v i r a l p o s t e x p o s u r e p r o p h y l a x i s in r e d u c ing s e r o c o n v e r s i o n a f t e r H I V - p o s i t i v e b l o o d expos u r e is b e y o n d the s c o p e of this article. Rather, this r e v i e w f o c u s e s o n e x p o s u r e - r e l a t e d f a c t o r s as a b a s i s f o r b l o o d e x p o s u r e p r e v e n t i o n a n d cost-effective p u r c h a s i n g strategies.
BACKGROUND T h e a c t u a l n u m b e r o f n e e d l e s t i c k s t h a t o c c u r is difficult to e s t i m a t e b e c a u s e as m a n y as 70% m a y go u n r e p o r t e d b y H C W s ? I n j u r i e s involving a n infectious source patient carry varying degrees of risk of infection, d e p e n d i n g o n the p a t h o g e n . Dise a s e t r a n s m i s s i o n will o c c u r in 2% to 40% of H C W s a f t e r h e p a t i t i s B v i r u s (HBV) e x p o s u r e , in 3% to 10% a f t e r h e p a t i t i s C v i r u s (HCV) e x p o s u r e , a n d in 0.2% to 0.5% a f t e r H I V e x p o s u r e (Table 1). 1 F o r all t h r e e diseases, h i g h r a t e s o f m o r b i d i t y , h u m a n suffering, a n d mortality, a n d i n c r e a s e d h e a l t h c a r e costs are a s s o c i a t e d w i t h s e r o c o n v e r s i o n . H B V i n f e c t i o n is the o n l y o c c u p a t i o n a l l y acquired, b l o o d - b o r n e i n f e c t i o n t h a t is v a c c i n e preventable. However, successful postexposure prop h y l a x i s is d e p e n d e n t o n t h e s o u r c e ' s infectivity s t a t u s a n d the t i m e l i n e s s of the p r o p h y l a c t i c treat-
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T a b l e 1. Risk assessment after occupational exposure to blood-borne pathogens 1 Risk of transmission
Virus
Percutanaous injury*
Mucosal contact or contact with injured (broken) skint
HBV
2-40%
HCV
3-10%
HIV
0.2-0.5%
Not quantified (transmission by this route has been documented; the magnitude of risk is probably high relative to that for HCV and HIV) Not quantified (transmission by this route has not been documented but is plausible) Not quantified (transmission by this route has been documented; pooled risk estimate, 0.1%)
Infectious material
Bite wound~:
Documented
Not quantified (transmission by this route has been documented)
Blood, blood products
Semen, vaginal fluid, bloody fluids, saliva
Urine, feces
Not quantified (transmission by this route has not been documented)
Blood
Blood products, bloody fluids, semen, vaginal fluid
Saliva, urine, feces
Not quantified (possible route of transmission in 2 cases of nonoccupational exposure)
Blood, blood products, bloody fluids
Semen, vaginal fluid, cerebrospinal fluid, breast milk, exudates, seresal fluids, amniotic fluid, saliva (during dental procedures)
Saliva, urine, feces
Possible§
Unlikely
Modified from Gerberding JL. Management of occupational exposures to blood-borne viruses. N Engl J Med 1995;332:444-51. Reprinted by permission of The New England Journal of Medicine, copyright 1995, Massachusetts Medical Society. *The risk estimates are based on pooled data evaluating percutaneous exposures to blood through needle punctures and other injuries inflicted by contaminated sharp objects. 1-Contact with intact skin is not a proved route of transmission of blood-borne viruses. However, small breaks in the skin may escape detection, and many experts consider contact with skin a potential route of transmission, especially when the surface area is large or the duration of contact is prolonged. SThe person inflicting the bite may be at risk for mucosal contact with bIood if the bite causes bleeding. {}These fluids have not yet been implicated in occupational transmission but are considered potential sources because they are likely to contain virus or have been implicated in other modes of transmission.
ment. 1 Because vaccines are not available for HCV or HIV, institutions wishing to provide a safer work environment should make it a priority to use needle devices that can prevent the HCW from coming into contact with potentially infectious blood on the tip of a needle. Other investigators have linked drawing venous blood with a higher rate of HIV transmission. Berry reported, "A greater frequency of needles used to draw venous blood was represented in the group of HCWs with documented seroconversion than in the group with reported needlestick injuries (50% vs 20%, p = 0.0002). "s This comparative analysis also did not find an association between injuries caused by needles used to connect intravenous (IV) lines and H W seroconversion (p = 0.013). s McCormick's study showed a high incidence rate of sharps injuries a m o n g phlebotomists (407/1000 employees per year) despite a low frequency rate of exposure (1/26,871 draws). 6 Technical expertise appears to be a factor in the low exposure frequency; however, a high rate of HIV seroconversion among phlebotomists has been reported. 7 NEW DATA
A recently published international case-control study of HIV seroconversion in HCWs after per-
cutaneous exposures to HIV-infected blood analyzed the risk factors associated with HIV transmission. 3 This retrospective study was conducted by the CDC in collaboration with French and British public health authorities. The case study population (n = 31) included 23 HCWs in the United States, 5 in France, and 3 in the United Kingdom. All the HCWs had a documented occupational percutaneous exposure to HIV-infected blood between January 1988 and August 1994 resulting in seroconversion. The control group of HCWs (n -- 679) had documented percutaneous exposure to HIV-infected blood, but were HIV seronegative 6 months after exposure. Analysis included demographic information about the exposure, stage of HIV infection in the source patient, and exposure-related information. 3 Two factors had an important effect on increasing seroconversion rates after percutaneous exposure to HIV-infected blood. These are (1) exposure to a large quantity of blood, defined as a procedure where a needle is placed directly into a vein or artery; a deep puncture, with or without bleeding; or a device visibly contaminated with the source patient's blood; or (2) exposure to blood from a source patient with terminal AIDS. 3 A third important factor was the postexposure use of zidovudine, which reduced the seroconver-
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sion rate by approximately 79%. The exposure variables related to seroconversion are most relevant to the identification of devices and procedures that put HCWs at greatest risk for disease transmission after percutaneous injury. Hence, venous access procedures pose the greatest occupational risk for HIV transmission. The results of this study further indicate the need for risk-based purchasing strategies for products that directly reduce this hazard. RISK ANALYSIS
Each institution has a unique risk profile based on treatment, facility, and staff variables. The necessary data can be gathered through a simple postinjury questionnaire that is completed at the time a needlestick is reported, s Experts agree that data collected should include the job classification of the injured HCW, type and size of needle used, location of the incident, the specific procedure performed, and other environmental details, a,9 Data analysis should focus on outcome measures, including injuries associated with highrisk tasks and related seroconversions. IMPLICATIONS FOR P U R C H A S I N G S T R A T E G Y
The CDC data confirming that specific tasks are associated with seroconversion should influence purchasing strategy. 3 Often, an institution's safetyrelated purchasing strategy is directed at outcomes, such as reducing the total annual n u m b e r of needlesticks. For example, needleless IV systems will effectively reduce the n u m b e r of needlesticks associated with IV manipulation, including punctures from piggyback needles, flushing heparin locks, aspiration from IV ports, or injecting medication into IV lines, a° However, this strategy is not likely to reduce disease transmission because needlesticks related to these tasks are not positively associated with seroconversion, s,l° Hence, such a strategy becomes a cost-intensive effort that has no apparent impact on reducing costly negative outcomes. Rather, risk prevention strategies should t a r g e t tasks and devices that involve large volumes of blood, the placement of a device in a vein or artery, or have the potential for deep injury. 3 Although such a strategy m a y not significantly reduce the total n u m b e r of needlestick injuries, avoiding this kind of exposure minimizes the risk of seroconversion among those HCWs at highest risk. 1 A study reported by Jagger, which related needlesticks to the device used, concluded that HCW exposure to blood during phlebotomy pro-
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cedures could be reduced if needle devices were redesigned so that HCWs' hands always remained behind the needle. 11 Therefore, hazard elimination should be the first consideration in the institution's risk analysis. Can the sharp device be eliminated by using a different product or procedure? If not, what devices are available to protect the needle during or after use? 9 Product selection criteria should include design and performance elements that would balance clinical patient care needs with safety needs. Specifically, choices must be made between a "passive" device, one that requires no action by the HCW, and an "active" device, one that requires the HCW to engage the safety feature. 9 Consideration must also be given to the training and education required to ensure adoption of and compliance with engineering controls. 12 P R O D U C T SELECTION
The product evaluation and selection process should be based on the institution's data-driven risk analysis, product substitution, and cost factors. Ideally, safety product selection should involve a multidisciplinary group, reflecting the breadth of an institution's interests, expertise, and user population. The model safety products evaluation team that Chiarello suggested included representatives from administration, infection control, employee health, materials management, waste management, clinical staff, central supply, risk management, industrial hygiene, and labor, when appropriate. 9 The product evaluation team approach supports an institution's need to establish priorities and focus intervention efforts in a cost-effective manner. It seems that innovative technology has inundated the marketplace in response to the need to reduce HCW exposure to blood-borne pathogens. These entrepreneurial efforts have eclipsed the purchaser's ability to objectively determine a product's efficacy, safety, and cost, which m a y be as m u c h as 20 times the cost of conventional devices. 1° Therefore, a rigorous product evaluation process is mandatory to objectively determine the value of any safety initiative. Selecting a subset of the user population to try products and provide feedback to the safety product evaluation team is an essential part of the process. 9 User acceptance of the new product is critical to the success of the safety intervention, and ultimately to the cost-effectiveness of the device, because haphazard use m a y negate the potential benefit. 8 Thus, for a product to be consid-
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e r e d cost-effective, it m u s t r e d u c e the total n u m b e r of h i g h - r i s k e x p o s u r e s a n d a s s o c i a t e d m o r b i d ity, a n d it m u s t e n g e n d e r a h i g h d e g r e e of u s e r c o m p l i a n c e . 1° CONCLUSION
I n m a n y institutions, a t t e n t i o n h a s b e e n f o c u s e d o n p r e v e n t i n g as m a n y n e e d l e s t i c k s as possible. H o w e v e r , e v e n if it w e r e p o s s i b l e to a c h i e v e this in a cost-effective m a n n e r , c u r r e n t r e s e a r c h s h o w s t h a t this s t r a t e g y w o u l d n o t a c h i e v e t h e u l t i m a t e goal: p r e v e n t i n g s e r o c o n v e r s i o n s . 1° T h u s , r e c e n t r e s e a r c h linking s e r o c o n v e r s i o n w i t h e x p o s u r e to a l a r g e v o l u m e of b l o o d m a k e s a c o m p e l l i n g a r g u m e n t f o r safety initiatives a n d p u r c h a s i n g strategies t h a t f o c u s o n h i g h - r i s k p r o c e d u r e s , e s p e c i a l l y t h o s e involving v e n o u s o r a r t e r i a l access. Poste x p o s u r e s u r v e i l l a n c e a n d t r e a t m e n t of H C W s w h o h a v e s i g n i f i c a n t e x p o s u r e s to b l o o d a r e costly a n d labor-intensive processes, with serious physical and emotional consequences for HCWs. T h e u l t i m a t e goal of r i s k m a n a g e m e n t , infect i o n control, a n d o c c u p a t i o n a l h e a l t h a n d safety p r o v i d e r s is p r e v e n t i n g t h e t r a n s m i s s i o n of disease. P r e v e n t i o n , t h e r e f o r e , m u s t i n c l u d e a p r o a c tive a p p r o a c h to r i s k r e d u c t i o n t h a t i n c l u d e s a v o i d a n c e of e x p o s u r e s t h r o u g h t a r g e t e d s a f e t y interventions, aggressive HBV immunization prog r a m s , a n d effective p o s t e x p o s u r e m a n a g e m e n t w h e n e x p o s u r e s occur. This r e v i e w i n d i c a t e s t h a t efforts to r e d u c e the i n c i d e n c e of s e r o c o n v e r s i o n a f t e r p e r c u t a n e o u s i n j u r y s h o u l d f o c u s o n s a f e r n e e d l e devices for v e n o u s access p r o c e d u r e s . S i m u l t a n e o u s i m p l e m e n t a t i o n of c o m p e t e n c y - b a s e d t r a i n i n g f o r phleb o t o m y tasks, i m p r o v e d i n j u r y - r e p o r t i n g m e c h a n i s m s , a n d p r o m p t a c c e s s to c o n f i d e n t i a l a n d c o m p e t e n t p o s t e x p o s u r e m a n a g e m e n t , a r e also critical to t h e s u c c e s s of safety initiatives. 1,9,12-14At a time when health care institutions are implem e n t i n g c r o s s - f u n c t i o n a l t r a i n i n g of n o n p h l e b o t o m y p e r s o n n e l to p e r f o r m v e n o u s a c c e s s p r o c e dures, b o t h in a n d o u t of t r a d i t i o n a l h e a l t h c a r e e n v i r o n m e n t s , the n e e d f o r c o m p e t e n c y - b a s e d t r a i n i n g in t h e u s e of v e n o u s access devices is imperative. 6 T h e safest device in the h a n d s of a n u n -
skilled u s e r u n d e r m i n e s a n institution's b e s t efforts to c o n t r o l costs a n d r e d u c e injuries. A comprehensive hazard surveillance system t h a t m e a s u r e s the severity of the risk, c o u p l e d w i t h a n effective s a f e t y p r o d u c t e v a l u a t i o n t e a m , will p r o v i d e i n s t i t u t i o n s w i t h the n e c e s s a r y inform a t i o n f o r cost-effective, r i s k - t a r g e t e d safety initiatives. REFERENCES 1. Gerberding JL. M a n a g e m e n t of occupational exposures to blood-borne viruses. N Engl J Med 1995;332:444-51.
2. Laufer FN, Chiarello LA. Application of costeffectiveness methodology to the consideration of needlestick-prevention technology. Am J Infect Control 1994;22:75-82. 3. Centers for Disease Control and Prevention. Case control study of HIV seroconversion in health-care workers after percutaneous exposure to HIV-infected blood--France, United Kingdom, and United States, January 1988-August 1994. MMWR 1995;44:929. 4. Mangione CM, Gerberding JL, Cummings SR. Occupational exposure to HIV: frequency and rates of underreporting of percutaneous and mucocutaneous exposures by medical housestaff. Am J Med 1991;90:85-90. 5. Berry AJ. Are some types of needles more likely to transmit HIV to health care workers? Am J Infect Control 1993; 21:216-7. 6. McCormick RD, Meisch MG, Ircink FG, Maki DG. Epidemiology of hospital sharps injuries: a 14-year prospective study in the pre-AIDS and AIDS eras. Am J Med 1991; 91(suppl 3B):301S-7S. 7. Jagger J. Risky procedures, risky devices, risky job. Advances in Exposure Prevention 1994; 1:4-9. 8. Wugofski L. Needlestick prevention devices: a pointed discussion. Infect Control Hosp Epidemiol 1992;13:295-8. 9. Chiarello LA. Selection of needlestick prevention devices: a conceptual framework for approaching product evaluation. Am J Infect Control 1995;23:386-95. i0. Orenstein R, Reynolds L, Karabaic M, Lamb A, Markowitz SM, Wong ES. Do protective devices prevent needlestick injuries among health care workers? Am J Infect Control 1995;23:344-51. 11. Jagger J, Hunt EH, Brand-Elnaggar J, Pearson RD. Rates of needlestick injury caused by various devices in a university hospital. N Engl J Med 1988;319:284-8. 12. Murphy D. The development of a risk management program in response to the spread of bloodborne pathogen illnesses. J Intraven Nurs 1995;18:$43-$7. 13. Update: Provisional Public Health Service recommendations for chemoprophylaxis after occupational exposure to HIV. MMWR 1996;45:468. 14. Gerberding JL. Prophylaxis for occupational exposure to HIV. Ann Intern Med 1996;125:497-501.