Presently, there are no legislativě standards in the Czech Republic banning health care workers with chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infection to do activities with a risk of the transmission of these viral infections to patients (surgeries and other invasive inter-ventions). In a range of developed countries in the world individuals with chronic HBV infection, HBeAg positive individuals, háve a restricted access to the risk interventions. A quantitative as-sessment of viremia is important in the health care workers infected with HBeAg-minus mutant of the virus. There are particular critical viremia values set up (sérum HBV DNA levels) which ex-ceeding in the health care workers leads to banning them to do the risk interventions. In cases of proved transmission of hepatitis B infection from a health care worker to a patient, the ban of do-ing risk interventions is a rule. Transmission of HCV infection from a health care worker to a patient is much less probable so the individuals with chronic hepatitis C are usually not forbidden to make invasive procedures. An exception are cases when there was a patient infected by a particular health care worker in the past. There are various attitudes to the health care workers with chronic HBV or HCV infection in various countries of the world. A necessity to reach a definite consensus is necessary. The first step to it are common recommendations of 12 European countries and the USA which are repeatedly cited in the text. We can expect that these problems will háve to be solved very soon in the Czech Republic too.

        Key words: Hepatitis B virus - Hepatitis C virus - Transmission of an infection from a health care worker to a patient - Prevention