The Human Immunodeficiency Virus (HIV) forms part of the genus Lentivirus, which itself forms part of the family Retroviridae. The virus is the cause of the disease called Acquired Immunodeficiency Syndrome (AIDS), which primarily results in a decline in the hosts immune system, making the host susceptible to life-threatening infections and diseases. HIV may be sub-divided into two separate types namely, HIV-1 and HIV-2. The difference between the two is mainly that HIV-1 is more easily transferred then the transfer rate of HIV-2, while the rest of the symptoms, characteristics, and outcomes are approximately the same. The virus occurs as a free floating virus particle as well as within infected immune cells such as CD4+ T-cells.
2. DISEASE PROGRESSION
Below is a General overview of how one could describe the progression of HIV
Figure 1: Overview of disease progression
The acute infection stage is often defined by acute retroviral syndrome (ARS), which is characterised by fever, lymphadenopathy, pharyngitis, skin rash, myalgias, and other common flu-like symptoms. These symptoms generally start occurring within the first 2-4 months of infection but could take up to 3-6 months to show. This stage of diagnosis is often written off as the common flu therefore necessary measures are not taken and a crucial point of defence against the HIV-1 virus, from a medical perspective, is overlooked.
Clinical latency, also known as asymptomatic HIV infection, is characterised by a lack of symptoms and an apparent healthy CD4+ T-cell count. The HIV-1 virus is still present and active during this period but a relatively stable viral load is maintained. This period is said to last up to 8 or more years but may vary from person to person.
Towards the end of the clinical latency period there is an increase in the viral load as well as a decrease in the CD4+ T-cell count. The progression of this period results in AIDS. The official diagnosis of AIDS is when the CD4+ count drops below 200/mm3. At this stage of infection the body becomes extremely vulnerable to opportunistic infections/diseases that ultimately result in death.
3. T CELLS AND EVASION OF THE VIRUS
T helper cells, which form a fundamental component for HIV-1’s means of infecting the human body, can be described as a subgroup of white blood cells (lymphocytes). The T helper cells are essential in the proper functioning of the adaptive immune system; the aspect of the immune system that creates immunological memory once initially being exposed to a specific pathogen and therefore providing immunity against the same pathogen if it recurs. Upon maturity, the T-helper cells express the surface protein CD4 and they themselves are referred to as CD4+ T-cells. The relationship between HIV-1 and T-helper cells is that HIV infects mature T-helper cells (CD4+ T-cells). The increasing infection of the CD4+ T-cells...