Hepatitis B virus (HBV) and hepatitis C virus (HCV) are the most prevalent
bloodborne pathogens. Infections caused by these organisms can become chron
ic and may lead to liver cirrhosis and carcinoma. Limited chemotherapy is n
ow available, but only HBV can be prevented through vaccination. Both virus
es are enveloped and relatively sensitive to many physical and chemical age
nts; their ability to survive in the environment may not be as high as ofte
n believed. As a result, their spread occurs mainly through direct parenter
al or percutaneous exposure to tainted body fluids and tissues. Careful scr
eening of and avoiding contact with such materials remain the most effectiv
e means of protection. Nevertheless, the indirect spread of these viruses,
although much less common, can occur when objects that are freshly contamin
ated with tainted blood enter the body or contact damaged skin. Germicidal
chemicals are important in the prevention of HBV and HCV spread through sha
red injection devices, sharps used in personal services (such as tattooing
and body piercing), and heat-sensitive medical/dental devices (such as flex
ible endoscopes) and in the cleanup of blood spills. Microbicides in vagina
l gels may also interrupt their transmission. General-purpose environmental
disinfection is unlikely to play a significant role in the prevention of t
he transmission of these viruses. Testing of low-level disinfectants and la
bel claims for such products against HBV and HCV should be discouraged. Bot
h viruses remain difficult to work with in the laboratory, but closely rela
ted animal viruses (such as the duck HBV) and the bovine viral diarrhea vir
us show considerable promise as surrogates for HBV and HCV, respectively. A
lthough progress in the culturing of HBV and HCV is still underway, critica
l issues on virus survival and inactivation should be addressed with the us
e of these surrogates.