What is the significance of a 'viral load' test in HIV management?

• A. It measures CD4 count to assess immune function.
• B. It measures plasma HIV RNA to monitor ART; decreasing indicates control; target undetectable <50 copies/mL (depending on assay).
• C. It measures HIV antibodies.
• D. It measures liver enzymes.

Answer: (B)

Viral load testing measures the amount of actively replicating HIV RNA in the blood and is used to judge how well antiretroviral therapy is controlling the infection. A decreasing or undetectable viral load signals effective treatment, good adherence, and a lower risk of disease progression and transmission. The goal is an undetectable level, typically below the assay’s detection limit (often around 20–50 copies/mL, depending on the test). If the viral load stays detectable or rises, it can indicate virologic failure due to poor adherence, resistance, or other factors, prompting adherence support and possible treatment changes. This differs from CD4 count, which reflects immune function; HIV antibody testing, which shows exposure; and liver enzyme tests, which assess organ health. In practice, viral load is checked after starting ART to gauge early response and then every 3–6 months once suppression is achieved.