Ever since its discovery by the CDC in the 1980s, HIV and AIDS have been scourges on humanity that, as of 2007, had killed more than 2 million people. Although we understand the infection and pathology of the virus, a cure has so far remained out of our reach, which makes HIV a deadly virus.
AIDS
Acquired Immunodeficiency Syndrome (AIDS) is the disease caused by the human immunodeficiency virus (HIV). The disease is characterized by a complete compromise and shutdown of the immune system, which takes place over many years. Normal immune systems can handle various levels of infection by bacteria or viruses, but individuals with severely compromised immune systems, such as in the case of an AIDS patient, cannot fight off even the most basic infections.
Pathogenesis
HIV is an RNA retrovirus, meaning that it is composed of only RNA strands, a reverse transcription enzyme, several important proteins and a protein coat. Research has revealed that there are also two critical glycoproteins embedded in the protein coat of the virus. The first, gp120, recognizes the CD4 receptor, which is only present on very specific T cells, certain macrophages and certain neural cells. Once the receptor has bound to gp120, the second HIV glycoprotein, gp41, inserts itself into the target cell's plasma membrane and causes the virus cell to fuse with the target cell. Once inside, the reverse transcriptase converts the virus RNA into DNA, which is inserted into the target cell's DNA. Cellular machinery is recruited to create more viruses, and eventually the cell bursts to release more virus into the environment.
How It Spreads
The HIV virus is spread in one primary way, and that is through contact between an infected person's fluids and a healthy person's fluids. This can be accomplished in several ways. One of the most common methods of transmission is sexual contact, where semen or vaginal fluid from one person mixes with the body fluids of another. The second method of transmission is blood contact, and this can happen through the use of dirty needles for drug injection. It can also happen if blood from an open wound on an infected person contacts an open wound on a healthy person. Transmission between an infected mother and a child during pregnancy can also occur in this way. Unfortunately, blood transfusions using infected blood can also cause AIDS.
How It Does Not Spread
Unlike other viruses, HIV does not survive well outside of a human body. It is not passed through physical contact, such as holding hands, and it is not passed by kissing unless there is blood in the mouth. HIV is also not passed by vector transmission, such as through a mosquito or a rodent, and it does not contaminate water supplies.
Treatment
Currently, antiretroviral agents are the only effective treatment against the HIV virus itself, and these only slow the infection process to the point of potential survival. At least for now, AIDS patients will have the disease the rest of their lives. Cutting-edge research is aimed at further understanding gp120 and gp41 so that drugs might be used to target them in the future.
Tags: target cell, between infected, healthy person, immune systems, infected person, into target