Preventing the spread of hepatitis B and C viruses: Where are germicides relevant?

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.