HIV stands for Human Immunodeficiency Virus. This virus infects a number of different cells of the human immune system. The most susceptible cell is a type of white blood cell called the CD4 T-lymphocyte, which plays a very important part in the functioning of the immune system. HIV slowly and steadly destroys these immune cells until the body is left defenseless against all and every disease. When the count of CD4 cells goes below a certain number (200 cells per cubic millimeter of blood), the person is said to have progressed to the AIDS stage, the final stage before death.
Viruses are tiny single cell organisms that can cause disease. Viruses are very picky and infect very specific cells which we call host cells. Their life cycle consists of entering a host cell, and replicating themselves using the machinery of the host cell. The host cell is eventually destroyed and the new virus cells are released by budding or at cell death when it bursts open.
HIV+ is a term used to denote any person who is infected by HIV. Similarly, sometimes the term HIV- is used to denote any person who is NOT infected by HIV.
AIDS stands for Acquired Immunedeficiency Syndrome. The word syndrome specifies that it is a condition or stage of infection and not a specific disease. The word "acquired" specifies that this syndrome is not genetic (hereditory) but acquired by an individual as a consequence of infection with HIV. Once HIV enters the human body, it slowly and steadly destroys the CD4 immune cells until the body is left defenseless against all and every disease. When the count of CD4 cells goes below a certain number (200 cells per cubic millimeter of blood), the person is said to have progressed to the AIDS stage. It is the final stage of HIV infection before death.
HIV is considered a new virus as no records of it exist in history or in dead bodies. Our best understanding of the origin of HIV is that it started in central Africa and started spreading, slowly at first, around 1930. The closest known virus to HIV is called SIVcpz and it is found in a certain species of chimpanzees in central Africa. This virus, SIVcpz, entered the human body by accident: these chimpanzees are hunted in a very bloody way and eaten raw or sometimes their blood is drunk by people. SIVcpz does not cause disease in humans, but it mutates (changes its structure) very rapidly. Unfortunately, it mutated to HIV in some human. This human then spread it to his/her sexual partners and they passed it on further. For many years HIV was limited to a small region of Africa, however, with the explosion in tourism, air travel, mobility of people, and many other factors that became common in the 1960s, the virus spread rapidly all over the world. Today, it is one of the worst nightmares for public health. As of May 2001 it has killed over 22 million people worldwide, 34 million are living with the infection and will die of it, and the dead have left behind 14 million orphans.
There are many viruses and bacteria that have made a transition from animals to humans by chance events. Each of these viruses can survive in only certain species of animals. In the case of HIV, it just so happened that the precursor virus is a chimpanzee virus, and these chimpanzees are native to Africa.
As explained in a question above, the emergence of HIV required two accidents. First was the introduction of SIVcpz into humans, and the second was its mutation to HIV. This is a rare event but it could have happened earlier. Furthermore, to spread, the infected person has to be able to pass HIV on to several other people, and they to others creating large chains. It seems that this combination of all three conditions occurred only recently.
In infected people, the virus is present mainly in the blood, and in the seminal fluids of man and vaginal secretions and breast milk of women. To transmit it from one person to another requires either the blood of an infected person enter into the body of another, or through sex, or from mother to child. The highest risk from sex is from anal sex, followed by vaginal sex, and a much smaller risk from oral sex. Blood contact can be through transfusion of infected blood, reuse of needles without sterilization for injections or tattoos, or by accidental pricks by such needles if they are not properly disposed. Click here for more questions on how HIV spreads.
The infection begins as soon as the HIV virus enters the blood system of a human being and starts replicating by infecting the CD4 cells. From that time onwards, once the viral reproduction cycle starts, the infection is established and we have no way of clearing it completely from the system. The infection is thereafter lifelong.
NO. It is acquired through sex with an infected person or if the blood of an infected person enters the body of another person through cuts, punctures or by transfusion.
There are many reasons for this. Among the most important are: (i) the host cell of HIV is a very important regulator of the immune system, so we cannot afford to indiscriminately destroy it; we have to design drugs that only destroy the infected cells. (ii) once HIV infects a host cell, it prevents the cell from displaying markers indicating that it is infected, thus making it hard for the immune system to tell whether a cell is infected or not. (iii) the virus can stay in a dormant state inside a cell for years. So even if a medicine can destroy all the infected cells, the virus reappears at a later date after the person has stopped taking the medicine. (iv) it mutates very rapidly, and learns to evade the medicines.
As far as we know there is no homeopathic or ayurvedic medicine that can destroy the virus effectively and completely. Some medicines, including ayurvedic can strengthened the immune system, thus reducing the severity of the infection and resulting opportunistic infections, however they cannot clear the system of all HIV as necessary for a cure. Many people are claiming to cure HIV using homeopathy or ayurvedic medicines, but so far all these claims are false. Unfortunately many people in desperation are going to these "doctors" and are being cheated of all their money.
There are many reasons for this. Among the most important are: (i) the virus mutates very rapidly, so using a part of the virus or an attenuated version of the virus to prime the immune system is not safe as the vaccine itself could mutate into the deadly version; (ii) since the human immune system cannot clear the virus even after years of very low viral load, the vaccine will have to be prevent infection from even taking hold -- such vaccines are called sterilizing vaccines; (iii) testing a candidate vaccine is a very long process as it is not easy to find control populations; (iv) the efficacy of a vaccine is very hard to determine as the control population has to be followed for decades during which their exposure to HIV has to be faithfully recorded. (v) experiments suggest that early vaccine candidates that work in the laboratory (in a petri dish) do not work in the human body.
Rajan Gupta