Oem012_ch24.qxp

24 HIV in the Workplace
Over 25 years have elapsed since the first cases of what would become known as the acquired immune deficiency syndrome (AIDS) were reported in 1981 [1]. Thecomplex interactions between the human immunodeficiency virus (HIV) and theworkplace are still being defined and understood. While occupationally acquired in-fections from HIV are of much individual concern, they are rare events [2]. HIV isneither the most common nor the most infectious bloodborne pathogen. In theUnited States, seroconversion related to employment has been documented in healthcare workers and in those who occupationally engage in sexual contact [3–5]. Themedical response to HIV exposure has been addressed by various health organiza-tions [6–8]. Because of the currently incurable nature of HIV infection, seroconver-sion after an exposure to human blood is often the foremost concern for anemployee. Prompt treatment following an HIV exposure can decrease the chances ofseroconversion. Therefore, evaluation and treatment of potential exposures are ur-gent medical matters. Occupational medicine providers should be prepared to eval-uate and treat or promptly refer employees who present following such an exposure.
This chapter will deal primarily with exposure to HIV from nonsexual contact withinfectious material. Occupational HIV surveillance, workplace limitations, and em-ployment restrictions, if any, for HIV-positive employees and candidates are also re-viewed.
Occupational Exposure to Bloodborne Pathogens: A Brief History
Previous experience with viral hepatitis has provided a framework for response toHIV. Hepatitis B, previously known as serum hepatitis, was noted to occur via par-enteral infection. Cases arose from blood transfusions, sharing of needles from illicitdrug use (e.g., during the Vietnam War), and through immunizations, including200,000 cases associated with infected lots of yellow fever vaccine among U.S. forcesin the 1940s [9]. The identification of the MS-1 (hepatitis A) and MS-2 (hepatitis B)strains by Krugman and colleagues [10] in the Willowbrook studies preceded the de-tection of the Australia antigen (now referred to as the hepatitis B surface antigen) inthe late 1960s by Blumberg and colleagues [11]. More complete understanding of he-patitis B pathophysiology was followed by routine serologic testing of blood transfu-sion units and patients infected with hepatitis and the eventual development of thehepatitis B vaccine. Because of the similar nature of their occupational risks and thetiming of a fuller understanding of pathogenesis, the groundwork in the global *The opinions expressed by the authors do not reflect the policy of the Department ofHealth and Human Services, the Department of the Navy, or the Department of Defense.
response to occupational risks for hepatitis B has the United States was the largest industry in 2006, employing over 14 million workers. Women repre- The magnitude of the number of health care sent nearly 80% of the health care workforce in workers (HCWs) exposed to bloodborne patho- America [25]. Worldwide, there are conservatively gens via occupational needlestick injuries became estimated to be 35 million HCWs, but this estimate clearer by the mid-1970s. Preventive strategies for does not include the millions of support staff who needlestick exposure in HCWs were proposed as also are at risk for occupational exposure [26]. Po- early as 1981 [12], the same year as the first case re- lice, firefighters, sanitation workers, and many oth- port of AIDS [1]. In 1982, Dienstag and Ryan ers have lower but real occupational risks for demonstrated a correlation between the intensity accidental exposure to human blood or body fluid and duration of human blood and body fluid ex- [27]. Most research and prevention measures have posure and the likelihood of hepatitis B conversion focused on HCWs, especially in the hospital set- [13]. The 1983 version of the U.S. Centers for Dis- ting. The results of these efforts have been mixed ease Control and Prevention (CDC) Guidelines for [28]. A recent anonymous survey of 582 surgical Isolation Precautions in Hospitals was the last to residents at 17 medical centers reported that 99% have a specific category for blood and body fluid of surgeons in training experienced a needlestick precautions [14]. The emergence of AIDS cases in at some time during their training. Only 51% of the early 1980s and subsequent identification of the most recent needlestick injuries were reported HIV [15–17] prompted the National Institute for Occupational Safety and Health (NIOSH) and The effectiveness of highly active antiretroviral other parts of the CDC to reconsider the utility of therapy (HAART) for HIV has increased the life ex- having a specific category of blood and body fluid pectancy of persons living with HIV/AIDS, thus in- precautions [18,19]. The phrase universal precau- creasing the number of HIV-positive sources. These tions has been promoted to raise awareness of po- therapies have lowered viral load in many of these tential infectious risks within health care systems.
same individuals, making exposure to their blood Each patient encounter is a potential risk; therefore, or body fluids potentially less likely to result in in- appropriate precautions must be universally ap- fection. Table 24-1 shows the CDC statistics for re- plied. The first occupational HIV infection, the re- ported occupational HIV infections in HCWs in sult of a needlestick injury, was reported in late the United States through 2006 [3]. Whether the 1984 [20]. By 1987, the CDC had reports of six result of improved prophylaxis, safety devices, em- cases of occupationally acquired HIV in the United ployee education, or underreporting, no occupa- States. Four of the six had needlestick exposures, tionally related HIV infections have been reported whereas the remaining two had extensive blood or body fluid contact from an HIV-infected patient[21]. Use of single-agent antiretroviral postexpo- HIV/AIDS Surveillance
sure therapy was discussed in a 1989 publication byHenderson and Gerberding [22]. The CDC devel- The CDC performs HIV/AIDS surveillance for the oped the National Surveillance System for Health United States and issues annual reports, most re- Care Workers (NaSH) to track occupationally re- cently providing data through 2005. General trends lated disease. In 1991, the U.S. Occupational Safety show a steady increase in the estimated number of and Health Administration (OSHA) released legal persons living with AIDS in the United States— guidelines to protect employees in an attempt to re- 421,873 at the end of 2005. Because it may take a duce or mitigate the effects of the estimated decade or more for an HIV-positive individual to 800,000 needlestick injuries that occur in the develop AIDS, and because universal testing is not the norm, it is not known precisely how many indi- HCWs face a wide range of workplace hazards, viduals in the United States are infected. The CDC including needlestick injuries and mucous mem- estimates that over 1 million people in the United brane exposures. The total number of exposures is States are HIV-positive and that a quarter of them unknown but may increase owing to increasing are unaware of their HIV status. The general trends numbers of workers at risk. The health care field in indicate that an increasing number of persons are Table 24-1
susceptible host target cells and free virus or virus Number of U.S. Health Care Workers with Documented contained in inflammatory cells either suspended and Possible Occupationally Acquired HIV Infection, in human blood or present in other body fluids or tissues. Transmission does not occur via vectors or Documented
Possible
fomites, intact skin to intact skin contact, the air- Occupation
Transmission
Transmission
borne-respiratory route, or the fecal-oral contact.
The dominant and characteristic form of ongoing viral infection and pathogenesis occurs with bind- ing of the virus-specific envelope protein complex, gp120/gp 41, to the CD4 molecule expressed on the surface of helper T-lymphocytes as part of T-cell technician/paramedicHealth aide/attendant responsiveness to foreign antigens [34]. Binding then initiates the next stages of the viral life cycle: penetration, conversion of the RNA genome to DNA by the unique viral enzyme reverse transcrip- tase, and integration of viral DNA with host cell DNA. Resting CD4+ T cells may harbor proviral DNA without progressing forward in the viral replication process [35]. CD4+ T cells that are im- munologically activated either before or after initial binding of HIV will continue the replication process via expression of viral messenger RNA, for- mation of viral proteins, followed by virion assem- bly and budding from the cell membrane. The specific cause of the immunologic activation has not yet been identified and may vary from patient to patient. Figure 24-1 demonstrates a simplified Source: Adapted from Centers for Disease Control and Prevention. Sur- life cycle of HIV. In addition to CD4, coreceptors veillance of Occupationally Acquired HIV/AIDS in Healthcare Personnel, as that play a role in HIV entry into host cells have of December 2006; available at www.cdc.gov/ncidod/dhqp/pdf/bbp/fact_sheet_clearance_revised_090507Dec2006.pdf.
been identified and are targets for pharmacologicintervention [36].
living with HIV/AIDS owing to both new cases ofinfection and lengthened life expectancy [30].
HIV Treatment
HIV treatment is a rapidly evolving field. Figure Pathophysiology of HIV
24-1 also lists the classes of HIV medication and in- HIV is an RNA-based retrovirus of the subfamily dicates their sites of action. The Food and Drug Ad- Lentivirus, a group of viruses that cause chronic cy- ministration (FDA)–approved medications for the topathic infections of the immune system of vari- treatment of HIV, as of early 2008, are listed in ous vertebrate species. HIV is closely related to the Table 24-2 [37]. Each drug generally has two to immunodeficiency viruses of nonhuman primates.
three names, which can complicate the understand- With the extraordinary growth in the human pop- ing of an HIV source’s medication history. Entry ulation in the last half of the twentieth century, and fusion inhibitors work by preventing the human penetration into remote forest habitats, and processes involved with HIV gaining entry into rapid transit, this virus appears to have made a suc- CD4+ cells. Because of their action early in the cessful species jump in the relatively recent past. It process, there is promise for these drugs in acute has been rapidly propagated and amplified by postexposure treatment [38]. However, their use is human behavior and susceptibility [31–33].
not currently recommended without expert con- Humans are the only known reservoir of HIV.
sultation [8]. Another recently added category of Transmission requires intimate contact between anti-HIV medication, the integrase inhibitors, acts Figure 24-1
Simplified life cycle of the HIV virus
Table 24-2
bors a pool of circulating virus with many different FDA-Approved HIV Drugs, Early 2008 (Generic Name, mutations. Clinically, it has been observed that a single drug in an infected individual is likely to se-lect for a preexisting resistant virus. Because Entry/Fusion Inhibitors
monotherapy has demonstrated rapid onset of viral resistance, the institution of highly active anti- Nonnucleoside Reverse-Transcriptase Inhibitors
retroviral therapy (HAART), which combines three or more drugs from different classes, has become the standard of care for individuals being treated Nucleoside/Nucleotide Reverse-Transcriptase Inhibitors
Acute HIV Infection
Clinically, the likelihood of transmission depends on the viral titer of the source and the volume and mode of contact of the infectious material. Virus can be recovered eventually from most body fluids Tenofovir DF, Viread, TDFZalcitabine, Hivid, dideoxycytidine, ddC and tissues, but only blood products, sexual fluids, Zidovudine, Retrovir, ZDV, azidothymidine, AZT breast milk, and visibly bloody fluids have been as- Integrase Inhibitors
sociated with transmission [40–43]. Based on these data, the CDC has issued a list of body fluids con- Protease Inhibitors
sidered to be infectious (Table 24-3) [8]. Viral titer is determined by the natural stage of infection, treatment, treatment failure, and individual viral Fosamprenavir, Lexiva, FOSAPV, FPVIndinavir, Crixivan, IDV Table 24-3
CDC Definition of Blood or Body Fluid Potential for Ritonavir, Norvir, RTVSaquinavir, Invirase, SQV Potentially Infectious
Combination Medications
Atripla: efavirnez, emtricitabine, tenofovir Trizivir: abacavir, lamivudine, zidovudine to prevent the integration of viral DNA into the host cell chromosomes. The role of this agent in Not Considered to Be Infectious
postexposure prophylaxis (PEP) is not yet estab- lished. The nucleoside/nucleotide analogues and the nonnucleotide reverse-transcriptase inhibitors interfere with reverse-transcriptase conversion of genomic RNA to the proviral DNA. The protease inhibitors interfere with the final steps that produce Because HIV undergoes essentially continuous replication via an error-prone reverse transcriptase, Source: From Updated U.S. Public Health Service guidelines for the man-agement of occupational exposures to HIV and recommendations for an individual with chronic infection typically har- postexposure prophylaxis. MMWR 2005;54(RR-9):1–17.
setpoint. In general, it is highest about 3–4 weeks pect has been reported in a police officer [51]. Iso- after infection and increases again in late-stage in- lated HIV transmission has not been associated fection or when a particular antiviral regimen is failing [44, 45]. Not surprisingly, clinical and epi-demiologic observations document that transmis- Prevention of Blood Exposure for Health
sion occurs more often from contact with infected Care Workers
individuals just prior to seroconversion, in late-stage disease, or with a persistent high viral load de- Occupational medicine professionals play a signifi- cant role in the ongoing implementation of a com- About 80% of newly antibody-positive individ- prehensive exposure control plan. Their role in uals recall a brief mononucleosis-like illness, the defining the plan will vary depending on the size so-called acute retroviral syndrome, which can and needs of a given institution. Table 24-5 con- occur shortly after transmission and 10–21 days be- tains the essential elements of a prevention pro- fore seroconversion. The clinical manifestations of HIV infection associated with chronic and progres- sive immunocompromise are not expected for at pathogens. OSHA provides a template exposure least many months, more commonly years, and oc- control plan to be modified to reflect local specifics [52]. A robust surveillance system for bloodborne Percutaneous exposure is consistently reported pathogen incidents evaluates the potential for oc- to result in seroconversion in about 1 in 300 con- cupational exposures among all workers in a med- tacts. However, the risk of actual contacts clearly ical treatment facility. This may involve employees varies with exposure factors and can be as high as 1 (both full and part time), temporary employees, in 20 with penetration of highly infective material contract employees (e.g., contract vendors, agency into highly vascular tissue [2, 48] (Table 24-4). In pools, per-diem employees, and individual service the health care setting, blood splashes to oral mu- providers), volunteers (including adults and stu- cosa and nonintact skin have been rarely associated dents of high school and college age) and medical, with transmission [49]. The normal concentration nursing, and other professional students.
of inflammatory cells in the human mouth could A workplace program to evaluate potential em- be expected to support receptive transmission, but ployee exposures must be available 24 hours a day.
saliva itself is inhibitory to virus. The rare reports of This can occur either on-site or at a referral facility.
transmissions owing to bites emphasize both the Regardless of where the evaluation is performed, extent of inflammatory disease and the presence of surveillance data detailing the specifics of exposure blood in the mouth of the biter [50]. HIV trans-mission following a punch to the mouth of a sus- Table 24-5
Essential Elements of an Exposure Control Plan
Table 24-4
Factors Predicting Transmission of HIV to Health Care Implementation of various methods of exposure control, in- Adjusted
Odds Ratioa (95% CI)b
Engineering and work practice controlsPersonal protective equipment Communication of hazards to employees and training aAll were significant at p < 0.01.
Procedures for evaluating circumstances surrounding exposure Source: Adapted from Centers for Disease Control and Prevention. Case-control study of HIV seroconversion in health care workers after percuta- Source: From Model Plans and Programs for the OSHA Bloodborne neous exposure to HIV-infected blood—France, United Kingdom, and Pathogens and Hazard Communications Standards, 2003; available at United States, January 1988–August 1994 MMWR 1995;50:931.
www.osha.gov/Publications/osha3186.html.
need to be collected. These data should protect the Table 24-6
identity of the employee. In addition to complying Sample Personal Protective Equipment Precautions with the OSHA sharps log requirement, this en- All employees using PPE must observe the following precau- sures timely feedback and identification of work- sites where training and procedure review need to Wash hands immediately or as soon as feasible after remov- be restarted owing to a turnover of personnel or need to be reemphasized to existing employees. An Remove PPE after it becomes contaminated and before leav- important task is to develop a culture of safety ing the work area.
Used PPE may be disposed of in [list appropriate containers within the entire medical treatment facility and a for storage, laundering, decontamination, or disposal].
climate where employees feel that they will be seen Wear appropriate gloves when it is reasonably anticipated that there may be hand contact with blood or OPIM andwhen handling or touching contaminated items or surfaces;replace gloves if torn, punctured, or contaminated or if their Training
ability to function as a barrier is compromised.
Utility gloves may be decontaminated for reuse if their in- The required elements of bloodborne pathogen tegrity is not compromised; discard utility gloves if they (BBP) training are outlined in the OSHA blood- show signs of cracking, peeling, tearing, puncturing, or dete-rioration.
borne pathogen standard [53]. Initial training at Never wash or decontaminate disposable gloves for reuse.
the onset of at-risk work and follow-up annual re- Wear appropriate face and eye protection when splashes, fresher training are required for all personnel at sprays, spatters, or droplets of blood or OPIM pose a hazard risk for bloodborne pathogen exposure. This may be accomplished with a variety of media, including Remove immediately or as soon as feasible any garment con-taminated by blood or OPIM in such a way as to avoid con- small or large group presentations, Web-based pro- grams, and written training guides. A written or Source: From Model Plans and Programs for the OSHA Bloodborne Web-based copy of the facility specific exposure Pathogens and Hazard Communications Standards, 2003; available at control plan must be available at the worksite with www.osha.gov/Publications/osha3186.html.
clear directions on what to do in the case of a po-tential BBP incident. Preemployment evaluations Proper handling and disposal of sharps and proce- offer an opportunity to remind future employees of dures for handling contaminated laundry and the first aid and response plan to blood or body clean-up of spills involving blood or other body fluid exposures and to emphasize the benefits of fluids are important to avoid exposure of cowork- ers. Although not always clearly considered in theareas at highest risk for BBP incidents, housekeep-ing and laundry personnel must have appropriate Personal Protective Equipment, Engineering
training, including how and where to report an ex- Controls, and Work Practices
posure. This training needs to be in an understand- The most important part of universal precautions is the use of personal protective equipment (PPE) Institutional commitment to universal precau- by all employees at all appropriate times. Table tions, engineering and work practice controls, and24-6 provides a sample PPE precautions guideline.
PPE can decrease the number of occupational ex- Engineering controls are the physical objects that posures substantially [56]. A clear, well-communi- isolate or eliminate a BBP hazard. Sharps boxes, cated, and easily accessible plan is crucial to achieve self-sheathing needles, and needleless access sys- the goal of employees presenting for prompt post- tems are examples that have been used successfully exposure evaluation and potential prophylaxis.
[54–56]. The revised OSHA standard clarifies theneed for employers to select safer needle devices Blood Exposure Evaluation
and to involve employees in identifying and choos-ing those devices. Work practice controls (e.g., pro- The evaluation of a worker with a potential expo- hibiting two-handed recapping of needles) are sure to HIV should be considered an urgent med- those institutional changes in the manner a task is ical matter that requires prompt attention. The performed that decrease the chances of an injury.
range of psychological reactions by those exposed

Source: https://www.oempress.com/downloads/23090.pdf