In people who are antiretroviral naive (have not started HIV treatment), HIV infection usually involves a steady increase in viral load accompanied by a fall in CD4 cell count. If HIV therapy is not started, this leads to the development of opportunistic infections (OIs) and ultimately, AIDS-related death.

Routine HIV care should therefore involve the regular monitoring of CD4 count and viral load to determine when to start HIV treatment. However, there are ongoing uncertainties about the precise rate of viral load increase in treatment-naive individuals and the relationship with falls in CD4 count. It is also unclear if co-factors such as age, sex and HIV transmission category are associated with faster changes in these key prognostic markers.

A recent large observational study showed that viral load increased steadily each year. This was accompanied by a mean fall in CD4 count of 78 cells/mm3 per year. However,  increases in viral load were significantly greater in older patients. Overall, there was no association between sex, race or injecting drug use and viral load increase. This suggests that the time to treatment will be quicker in older patients.

The full article can be read here.