Viral load and CD4 count are the two most important laboratory tests for monitoring HIV and treatment response.

What is Viral Load?
Viral load measures the amount of HIV in the blood. It is expressed as the number of copies of HIV RNA per milliliter of blood.

Viral Load Goals:
The goal of ART is to achieve and maintain an undetectable viral load (typically <50 copies/mL). This indicates effective treatment.

What is CD4 Count?
CD4 count measures the number of CD4+ T cells in the blood. These cells are crucial for immune function and are the primary target of HIV.

Normal CD4 Range:
Normal CD4 count is 500-1500 cells/mm┬│. HIV progressively reduces CD4 count if untreated.

Monitoring Schedule:
Viral load: Baseline, 4 weeks after starting ART, 12 weeks, then every 3-6 months
CD4 count: Baseline, then every 3-6 months

Interpreting Results:
Undetectable viral load + rising CD4 count = Treatment working well
Detectable viral load = May indicate adherence issues or resistance

Clinical Significance:
CD4 count helps assess immune function and need for opportunistic infection prophylaxis. Viral load indicates treatment effectiveness and transmission risk.

U=U Concept:
Undetectable viral load means untransmittable - people with sustained undetectable viral load cannot transmit HIV sexually.