Now let us see effects that a person might experience after getting infected with HIV virus. The person who gets infected by HIV virus (knowingly or unknowingly) does not develop positive HIV antibodies immediately; in fact it takes between 2 to 4 months to turn the HIV antibodies into positive (which can be confirmed by tests such as ELISA and western blot). The starting period of infection of HIV virus is also called primary stage of HIV infection. During this period, the infected person (although this is not what all the infected patients experience, but these are general symptoms) experience a flu-like situation, the person might experience fever for several weeks. Soared throats/mouth, frequent fever, muscles and join pain, swollen lymph nodes in the neck etc. are some of the common symptoms experienced by most of the AIDS patients during their primary stage of infection. In most of the cases it is found that the above enlisted symptoms vanish as soon as the HIV virus turns positive. In this phase, the virus starts spreading (multiplying) inside the body of the infected person and as he has no symptoms of AIDS, only a test can tell whether the person is infected with HIV.

As given above, after the patient passes the primary stage of infection, the virus starts multiplying inside the host’s body. The viral reproduction depends on many factors such as physical condition, immune system etc. of the host. Every day more than some millions (or sometimes billions, the number is not same for everyone and everyday) HIV viruses are produced inside the patient’s body. AIDS is a very slow progressing disease, the procedure of HIV virus multiplying generally takes about 8 to 10 years. Once the HIV virus is reproduced up to a certain extent, a situation called AIDS develops in patient.

Now let us see, how the virus works inside the patient’s body. In biological words, every living cell has its set of functions defined, such as CD4 cells, which has a function to fight with diseases and provide make our immune system stronger. We can say that every cell is programmed to do some activity. The HIV virus; reprograms the cells of immune system and converts them in cells that produces more HIV viruses (as HIV viruses cannot reproduce more HIV viruses or cannot replicate itself just like a living cell can do). This process continues until human immune system becomes so weak that it cannot fight even a simple disease that did not need any special dose of medicine.

HIV virus attacks CD4+T cell, which is also known as T-helper cell of Immune System. HIV virus is called retroviral, because it takes help of enzyme called Reverse Transcriptase, to convert RNA strands into DNA. As a first step of infecting a healthy T-helper cell, HIV virus gets itself attached to the CD4 protein of the T-helper cell wall with the help of its gp120 Envelop protein. This works as a gate opener, the cell wall of the T-helper cell allows the viral core of the HIV virus enters into T-helper cell after gp120 protein docks itself to the CD4 protein. Further, the reverse transcriptase inside the HIV virus core, copies the virus’s RNA into DNA. This newly generated DNA is carried to the T-helper cell’s nucleus by an enzyme called viral integrase, where the virus’s DNA binds itself with the T-helper cell’s DNA. This mutated DNA then creates messenger RNA (mRNA), and in this process it uses the enzymes available in T-helper cell. The messenger RNA is just like blue-print of instruction which tell how to create new viral proteins.

This mRNA is carried out of the nucleus of the T-cell by the cell’s own enzymes. Now the virus inside the cell uses cell’s proteins to make more long chains of viral proteins and enzymes. Here the infected T-helper cell comes completely under control of the HIV virus and works as new virus producing factory. The newly created viral proteins, RNA and enzymes gather at the edge of the T-helper cell ready to get into a protective sheathe and infect another healthy T-helper cell. An enzyme which is called protease cuts the polypeptides into viral proteins. The newly created HIV virus particles then leave the infected T-helper cell and get their own protective sheathe (which again is made up of membrane of the infected T-helper cell) and head towards the other Immune System cells. This process is also called budding and about thousands of T-helper cells are infected slowly until the CD4 cell count reduces to a very low level. At certain level when the number of T-helper cells per millimeter in blood goes below a particular number, the person is considered to have developed AIDS.

It is believed that the HIV virus inherits its properties from a virus SIV (Simian Immunodeficiency Virus), which is found in monkeys. The AIDS virus also has developed its own characteristics along with those which it inherits from SIV. The SIV virus has exactly same genetic structure as that of HIV and both the viruses are transmitted same way from one host to another. The SIV virus causes AIDS in monkeys and has exactly same effects on them but it does not show any such effect on humans, whereas HIV causes AIDS in humans but not in monkeys. There are again many interesting stories/guesses/hypothesis as how the HIV virus born from the SIV virus? And how SIV virus got mixed in the human blood?

The AIDS virus was first discovered around year 1980 in the United States. A group of young gay men and also some drug users; were getting ill often, and there was no trace of the disease that they were suffering from. Most of the diseases they were falling prey of were related to the immune system. As it was not known that how much time the disease takes to surface? And how the disease spreads? The virus of AIDS found new home for itself from one man to another in the same group and also those who came in sexual contact or used the same syringe which was used by infected person. After some months, people from the group began to die, the diseases which killed all those people, were some of the common diseases which affects human at much extent if they have a damaged immune system. The T cells, also known as CD4 cells which help human body in fighting with the diseases were found damaged and there level was lowered in the patients suffering from the mysterious disease. It was outbreak of the new disease and it was identified and named AIDS (Acquired Immune Deficiency Syndrome) in 1981. Doctors started research in order to find out the possible causes of the disease. First, it was not known whether AIDS was caused by viral infection or something else until two doctors Luc Montagnier and Robert Gallo found the virus causing AIDS. The virus was named Human Immunodeficiency Virus (HIV).

Further in 1985, a blood test was formulated which helped in identifying if a person was carrying HIV. Since 1985, this blood test is used effectively for diagnosing HIV infection. Some more tests were also found to help in diagnosing the virus and the disease using the saliva and urine.

During first few years of the detection of the new disease AIDS, all the possible reasons of spread of the disease were unknown. This helped the disease spread from one infected person to another. Back in the decade of 60′s, there were very rare chances of a disease spreading across continents or countries. It was possible only when one person traveled from one country to another and carried the disease knowingly or unknowingly. The spread of AIDS is also said to be related with the same situation. It is said that when flight attendants used to fly across the seas, they had many sex partners in almost all the countries they visited. This helped AIDS spread from Africa and allowed it to enter in America.

After few years, all the possible reasons which helps AIDS virus to spread from one person to another were revealed, such as blood transfusion from an infected person to a healthy person, sexual intercourse between infected person and a healthy person, use of syringe etc. Right from the time of outbreak of the virus, it has infected over 50 million people and killed about half of the same till today (The number of people infected and killed due to AIDS might change, as there is a huge difference in official and unofficial data). But the right cure for the virus has not yet been discovered.