Bloodborne Pathogens in the Workplace

Abstract

Occupational risk to healthcare workers from infections with bloodborne pathogens has been recognized since the mid-twentieth century. Early reports around 1950s on “serum hepatitis” subsequently led to identification of hepatitis B as the causative agent in the bloodborne infection. In the early 1970s, serological tests became available for the diagnosis of infection with both hepatitis B and hepatitis A viruses. Non-A, non-B hepatitis (hepatitis C) emerged as a second bloodborne infection but, because of the lack of a serologic marker, the prevalence of the disease and its occupational risks were not appreciated. With the identification of human immunodeficiency virus (HIV) as the viral pathogen of the acquired immunodeficiency syndrome (AIDS) in the mid-1980s, healthcare workers became very concerned about the occupational risk to HIV infections due to exposure to the infected patients. The potential occult infectivity of blood has been emphasized with the documentation of 57 occupationally transmitted infections with HIV-1 in the United States. Since the first occupational transmission was reported in 1984, healthcare and laboratory administrators, as well as those in the public sector, have reexamined the infection control aspects of their work practices and have begun to analyze and develop equipment and procedures to minimize exposures. While majority of the occupational infections in healthcare workers are due to the three bloodborne viruses, HBV, HCV, and HIV, any septicemic infection (viremia, parasitemia, bacteriemia, or fungemia) may pose a potential risk of transmission of the pathogen to healthcare professionals via either percutaneous route (needlestick or sharps injury) or mucocutaneous route (contact with nonintact skin or mucosa of the eyes or mouth). Because infection with HIV and other bloodborne pathogens is not always clinically apparent, and the infectious potential of blood and other body fluids is not always known, the Centers for Disease Control (CDC) recommended “universal blood and body fluid precautions” in 1987. This approach emphasizes that blood and body fluid precautions should be consistently used for all patients and their clinical specimens and tissues. The “universal precautions” strategy has formed the foundation for federal guidelines through the CDC and regulations from the Occupational Safety and Health Administration (OSHA). Both organizations recognize that this practical approach to safety will not only minimize the risk of occupationally acquired HIV-1 infection but also serve to protect against occupational infection with other bloodborne pathogens such as hepatitis B, hepatitis C, human T-cell leukemia viruses I and II, HIV-2, and, to a large extent, prions (agents causing Creutzfeldt–Jakob disease). Nonetheless, a substantial number of percutaneous exposures continue to occur in the healthcare setting, despite implementation of the universal precautions guidelines. The risks to healthcare and laboratory workers are dynamic because of the availability of vaccines, antiviral treatment, and recognition of new agents and interactions with old ones. It is the purpose of this chapter to provide an overview of the epidemiology, risk of transmission, and the recommended or regulated strategies to prevent occupational transmission of viruses (HIV and hepatitis) and other bloodborne pathogens. Keywords: environmental survival; epidemiology; hepatitis B; hepatitis C; human immunodeficiency virus 1; occupational HIV-1 transmission; postexposure management; precautions; prevention; retroviruses; risk assessment