14/05/2026
HIV – Causes, Risk factors, Symptoms, and Prevention.
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Introduction
HIV is a virus that attacks the immune system, which is our body’s natural defense against illness. The virus destroys a type of white blood cell in the immune system called a T-helper cell, and makes copies of itself inside these cells. T-helper cells are also referred to as CD4 cells.
The virus is actually not one, but several different viruses in the class of Retroviridae and the genus Lentivirus. The species differs and there is a larger list of subtypes. There are two major types: HIV1 and HIV2 – HIV1 is thought to originate from chimpanzees and gorillas in western Africa; HIV2 originates from sooty mangabeys (another ape) found in Senegal and Ghana. HIV1 is the more deadly and is the cause of the AIDS pandemic and can be divided into the M, N, O, and P subgroups, but HIV2 is also known to cause AIDS.

Structure of HIV
As HIV destroys more CD4 cells and makes more copies of itself, it gradually breaks down a person’s immune system. This means someone living with HIV, who is not receiving treatment, will find it harder and harder to fight off infections and diseases. HIV spreads through bodily fluids that include:
Blood
Semen
Vaginal and re**al fluids
Breast milk
Replication process of HIV viruses in human body
The virus infects the body’s macrophages, dendritic cells, and T-cells, viz. most often the CD4+ lymphocytes, by attaching itself to them via its gp120 protein to the e.g.
T-cell’s CD4+ protein. The CCR-5 protein then induces the fusion of the membranes. An inherent property of lentiviruses is that they have a single-strand RNA strand, not DNA, and this strand is injected when the cytoplasm’s merge as the HIV’s membrane fuses with that of the T-cell.
The RNA is converted into DNA by reverse transcriptase and is inserted into the T-cell’s genome strand using DNA integrase. Hence, the virus is literally replacing part of the human body.
The infected T-cell now produces HIV
