<unk> , also known as viral burden, is a numerical expression of the quantity of virus in a given volume of fluid, including biological and environmental specimens. It is not to be confused with viral titre or viral titer, which depends on the assay. When an assay for measuring the infective virus particle is done (Plaque assay, Focus assay), viral titre often refers to the concentration of infectious viral particles, which is different from the total viral particles. Sputum and blood plasma are two bodily fluids from which<unk>  is measured. As an example of environmental specimens, the<unk>  of norovirus can be determined from run-off water on garden produce. Norovirus has not only prolonged viral shedding and has the ability to survive in the environment but a minuscule infectious dose is required to produce infection in humans: less than 100 viral particles.<unk>  is often expressed as viral particles, (virions) or infectious particles per mL depending on the type of assay. A higher viral burden, titre, or<unk>  often correlates with the severity of an active viral infection. The quantity of virus per mL can be calculated by estimating the live amount of virus in an involved fluid. For example, it can be given in RNA copies per millilitre of blood plasma. Tracking<unk>  is used to monitor therapy during chronic viral infections, and in immunocompromised patients such as those recovering from bone marrow or solid organ transplantation. Currently, routine testing is available for HIV-1, cytomegalovirus, hepatitis B virus, and hepatitis C virus.<unk>  monitoring for HIV is of particular interest in the treatment of people with HIV, as this is continually discussed in the context of management of HIV/AIDS. An undetectable<unk>  does not implicate a lack of infection. HIV positive patients on long-term combination antiretroviral therapy may present with an undetectable<unk>  on most clinical assays since the concentration of virus particles is below the limit of detection (LOD).
Viral load
Viral culture
HCV genotypes
NS1 antigen test
Malaria culture
Coronavirus breathalyzer
Rabbit test
Rabbit Test