The US labor force is composed of 136 million persons, 6 million of whom are healthcare workers with potential patient contact (16,17). Approximately half of these are registered or licensed practical nurses. An additional 3 million persons work in healthcare-support occupations and may have patient contact, including nursing aides, orderlies, and attendants (1.3 million); home health aides (560,000); and medical or dental assistants (600,000) (16,17). These estimates do not include persons without routine patient contact employed in such occupations as healthcare administrators, medical secretaries, and other clerical staff (16,17).

From 2000 to 2002, the Department of Labor reported an annual average of 77 healthcare worker deaths with the "industry" categorization versus 93 deaths with the "occupation" category (12). Deaths from transportation accidents and assaults and violent acts accounted for most. To address the latter problem, NIOSH recently published the monograph Violence: Occupational Hazards in Hospitals (http://www.cdc.gov/niosh/2002-101.html).

Specific data are reported for some but not all healthcare worker occupations in the "occupation" classification (Table 1). For example, an annual average of 10 doctors, 18 registered nurses, and 18 health technologists/technicians died. In addition, statistics maintained by the National EMS (Emergency Medical Services) Memorial Service show that ≈12 emergency medical service workers are killed annually, including 13 in 2002 (18). The EMS deaths are not specifically noted in the Department of Labor statistics; therefore, whether these deaths are included in the overall number is uncertain.

CDC estimates that, in 1983, 10,000 healthcare workers became infected with hepatitis B through occupational exposure (M.J. Alter, pers. comm.). The natural history of hepatitis B infection indicates that chronic infection developed in 5%–10% (500–1,000) of these persons. Although estimates vary, as many as 15%–25% (75–250 persons) of those with chronic infection will die from a hepatitis B–related complication, including cirrhosis or hepatocellular carcinoma (19). Since the time from infection to serious medical disease in the subset with these complications typically is about 20 years, most of these deaths can be expected to occur during this decade.

The risk of hepatitis B has diminished by >90% since the introduction of standard precautions and a recombinant vaccine (11). Despite vaccine availability, however, coverage is incomplete because >30% of workers refuse to be vaccinated (11). As a consequence, CDC estimates that, in 2002, another 400 healthcare workers became infected with hepatitis B virus, a number that has been stable since 1995 (M.J. Alter, pers. comm.).

CDC estimates that 3.9 million persons in the United States, or 1.8% of the population, have been infected with hepatitis C virus and that 2.7 million (1.3%) are chronically infected (20,21). Healthcare workers as a group have the same hepatitis C virus seroprevalence as the rest of the US population (20). However, transmission from a hepatitis C–infected patient to a healthcare worker occurs in 1%–3% of percutaneous exposures (22). With an estimated 380,000 percutaneous injuries annually (23), 50–150 transmissions would be expected, assuming that hospitalized patients have the same hepatitis C virus seroprevalence as the rest of the US population. Our understanding of the natural history of hepatitis C virus (HCV) continues to evolve; however, as many as 5% of those infected, or 3–8 healthcare workers annually, can be expected to die of liver disease.

This estimate may be low because hospitalized patients in some regions may have rates of HCV infection well above that of the US population, raising the likelihood of exposure to a positive source case. HCV seroprevalence of at least 5% has been reported in several groups who are frequently hospitalized. These groups include patients requiring dialysis (20), intravenous drug users with or without HIV infection (20), and perhaps patients in psychiatric hospitals and outpatient facilities (24).

CDC distinguishes between "documented" and "possible" occupational transmission of HIV. Documented infection refers to documented seroconversion in healthcare workers after occupational exposure or other laboratory evidence of occupational infection. Possible infection refers to history of occupational exposure to infected blood or other fluid in healthcare workers without identifiable behavioral or transfusion risks, but for whom seroconversion specifically resulting from an occupational exposure was not documented, i.e., a baseline, postexposure test for HIV was not performed (25).

To date, 26 (46%) of 57 US healthcare workers with voluntarily reported, documented, occupationally acquired HIV infection have progressed to AIDS, as have 121 (88%) of 138 healthcare workers with possible occupational transmission (25). Job-specific information is available for persons with either documented or possible disease. Twenty-four (42%) of 57 proven transmissions have occurred in nurses, 16 (28%) in clinical laboratory technicians, and 6 (11%) in nonsurgical physicians. Among the 138 persons with possible occupational acquisition, in addition to the occupations above, cases were noted among 12 emergency medical technicians (9%), 6 surgeons (4%), 15 health aide/attendants (11%), and 13 housekeepers and maintenance workers (9%). This distribution by occupation may be applicable to other infections transmitted by percutaneous injury, such as hepatitis B and hepatitis C, but comparable information from recent studies of these infections is not available.

Antiviral therapy to manage an occupational exposure to HIV has resulted in severe hepatitis requiring liver transplant, though no therapy-related deaths have been reported (26). The number of healthcare workers who have died from proven or probable occupationally acquired HIV infection has not been reported, but some have died and risk for serious complication persists (27).

Tuberculosis has long represented an occupational threat to healthcare workers (28). This risk became particularly evident during the late 1980s and early 1990s, when several nosocomial outbreaks of multidrug-resistant tuberculosis occurred in the United States. During these years, workers experienced a tuberculin conversion, and several developed active drug-resistant disease (29). The infection was fatal in at least 9 immunocompromised healthcare workers (30). Treatment for occupationally acquired resistant tuberculosis also has resulted in death (31). Healthcare workers who became latently infected with multidrug-resistant tuberculosis strains at this time remain at risk for disease reactivation (32).

In 2003, CDC and the American Thoracic Society revised the recommendation for treatment of latent Mycobacterium tuberculosis infection with pyrazinamide and rifampin because of an unexpectedly high rate of hepatotoxicity with this regimen (33). According to CDC, 6 healthcare workers were included in the 49 persons in whom severe hepatitis developed or death occurred. One healthcare worker died from this complication (K. Ijaz, pers. comm.).

To place healthcare worker risk into context, we applied the same approach to derive average annual death rates among several worker groups for the 3-year period 2000–2002 (Table 3). The US workforce has a rate of ≈41 occupational fatalities per million workers. Fishermen and construction workers have the highest rate (>1,000 deaths per million workers annually). Members of the military (361–671 per million), police and related protective service workers (108 per million), and firefighters (93 per million) also have markedly elevated rates. Lawyers (7–14 per million) and waiters (5 per million) have relatively low rates of occupational death.

The risk of acquiring a work-related fatal infection represents a substantial risk to healthcare workers in developing countries (34). In addition to viral hemorrhagic fevers, occupationally acquired tuberculosis in Africa is increasingly recognized. Reports from Malawi (35), Ethiopia (36), and South Africa (37) describe substantial rises in active cases of tuberculosis among healthcare workers, many of whom die of the disease (25% in a series from Malawi). Few reports have examined the occupational risk for HIV infection in disease-endemic, resource-poor countries, but transmission is likely (38).

We estimate that 17–57 US healthcare workers per million employed die annually from occupational infections and injuries (Table 2). However, the number of deaths that results from occupationally acquired infection is an educated guess at best. We projected the potential consequences of only 4 diseases by relying on the published prevalence, transmission rate, and natural history of these infections. Our results therefore may underestimate the actual occupational death rate for these diseases. Furthermore, these estimates do not account for deaths from other infections, which demonstrates the problems engendered by the current lack of a national tracking system. This finding stands in contrast to the rigorous approach used to track occupational deaths of various other workers, such as police officers and firefighters (39,40).

The recent experiences with SARS and smallpox vaccination have demonstrated the vulnerability of healthcare workers to occupationally acquired infections. In addition, these events have served as a reminder of the critical societal responsibility of the healthcare worker. Although not as central to a national disaster response as protective service workers, healthcare workers are a critical component and in this capacity may incur risk to their health.

We recommend that national organizations assume responsibility for accurately tracking deaths caused by occupationally acquired infections. A nationwide tracking system will accomplish several important goals. First, it will determine the magnitude of the problem and inform future interventions. This approach has been used successfully with needlestick injuries: a problem was identified and quantified, then assessable preventive measures (e.g., the safer needle system) were put into place. This system could also lead to appropriate financial compensation. In 1976, the Public Safety Officers' Benefits Program was initiated to provide a 1-time financial benefit to survivors of police officers, firefighters, and emergency workers killed in the line of duty. The benefit also extends to those who become permanently and totally disabled as the result of trauma sustained in the line of duty.

This approach was invoked recently as the national smallpox vaccination plan was initiated. Because of healthcare worker reluctance to accept a vaccine known to cause fatal reactions, if only rarely, the government opted to extend this program to cover healthcare workers for this complication. This decision was a good start in acknowledging the unique occupational hazards of healthcare but should not remain an isolated decision made at a politically charged moment.

Most of all, a national registry would provide an ongoing reminder of the risk of caring for others, by raising awareness among laypersons and professionals alike. The 9 million persons employed in the healthcare industry and their families merit better protection for their health and greater recognition for their contributions.