Diseases Progression: Effect of HIV Virus on the Immune System - Term Paper Example

Research is continuing and scientists and researchers are hopeful that they will be able to find out a cure for this multi-faceted virus but so far, no major breakthrough has been reached. What we do know is that this is an RNA retrovirus with immense genetic variation and mutation rate. It has two strains, HIV-1 and HIV-2, and they both show tropism for macrophages and CD4+ T cells and destroy them which culminate in complete paralysis of the body’s immune system. Multi-organ diseases start to develop until opportunistic infections become life-threatening.

This is the last stage of the disease known as AIDS. Prevention is the only successful management of this disease. Since sexual pathway is the most common route of transmission, protected sex with limited sexual partners, abstinence from reusing syringes and screening of pregnant women as well as blood donors is the most effective way to prevent this disease. Let us take an in-depth look at HIV and disease progression. HIV stands for Human Immunodeficiency virus which causes a syndrome of immunodeficiency, AIDS or Acquired Immunodeficiency Syndrome.

Thus HIV is the causative agent for AIDS. What is HIV? HIV belongs to the family of retroviruses, genus lentivirus, which are typically associated with long incubation periods and chronic opportunistic infections. They are transmitted as single-strand, enveloped RNA viruses that enter human cells, use their own reverse transcriptase enzyme to change into double-stranded DNA, enter the nucleus of the cell and become incorporated into human DNA using integrase enzyme. This process can be reversed to produce single stranded-RNA viruses which are released into the blood and go on to enter other normally functioning cells.

What sets HIV apart from all other viruses is the massive amount of genetic variability that it shows. This is due to the extremely rapid replication cycle that it follows. This can be understood by the fact that HIV generates 1010 virions everyday, has a mutation rate of about 3?10-5 per nucleotide base per cycle of replication and uses reverse transcriptase as a replication agent (Robertson, Hahn, & PM, 1995). Thus, the chances of genetic variability are higher than any other virus known to science as yet.

This is a major hurdle in developing a curative medicine against this virus as we shall see later. There are two strains of HIV, HIV-1 and HIV-2. HIV-1 is the most common type and is found in all parts of the world. While both the strains eventually culminate in AIDS, HIV-1 is said to be more virulent and easily transmissible which is it is found all over the world. HIV-2 is relatively milder initially, has a longer incubation period and is not as easily transmissible. As a result, it is found in certain parts of Africa only.

One of the most important characteristics of HIV that form the core of their disease causing process is their tropism. Tropism refers to the tendency of a virus to infect a certain type of cell. In case of HIV, this type of cell belongs to the immune system but more on that later. Origin and Spread of HIV There are different theories as to how the virus evolved into its modern form. All of these theories conclude on the fact that the