Current treatment regimens for HIV infection generally employ combinations of
three or more potent antiretroviral drugs, which in many cases can drive down
the level of virus in the body to undetectable levels. However, this approach
is not always successful. A significant number of individuals have
persistently high levels of HIV despite potent medication, while others
experience only transient virological suppression before their viral load
rapidly rebounds to near pre-treatment levels.
One of the major causes of treatment failure is HIV drug resistance – the
"Achilles’ heel" of antiretroviral therapy. This section explains what causes
HIV resistance, how it can be monitored, and what steps can be taken to
minimise its potential impact on successful treatment.