Viral load represents the amount of virus in a body fluid, e.g. given in nucleic acid copies per milliliter blood. Determination of viral load is part of the therapy monitoring during chronic viral infections and in immunocompromised patients, e.g. after bone marrow or solid organ transplantation. Currently, routine testing is available for HIV-1, Cytomegalovirus, Hepatitis B virus, and Hepatitis C virus.
