Cawse, Kerry-Anne2009-09-082009-09-082009-09-08http://hdl.handle.net/10539/7206Using a simple model of HIV-1 viral load and infected CD4+ count, with easily measurable coe cients, valid on time scales of approximately a month, we nd that HIV-1 is understood by sequential outburst of viral populations with delay between populations. AIDS is characterised by shorter delays between viral populations and HAART is characterised by longer delays between viral populations, as evidenced in observed viral blips. Infected CD4+ dynamics is understood by sequential outburst with overlap of CD4+ populations. We argue that viral load and CD4+ counts must be in phase and present a model in di erential equations that supports this conclusion and is consistent with decay rates discovered by the outburst model.enThesis