What is the difference between HIV and AIDS?
The human immunodeficiency virus (HIV) is a retrovirus that infects the cells of immune system. It attacks T-helper lymphocytes that contain CD4 protein – and these lymphocytes are critical for immune response. Without special treatment HIV copies itself extremely fast (producing from 10 up to 100 billion new viruses daily) continuing to kill T-cells and weakening the immune system.
For several years the decline in T-cells is almost unnoticeable for an infected person. But when CD4+ T-cell count falls below 200 cells per cubic millimeter of blood it causes grave course of opportunistic infections (while normal immune system successfully fights these infections). An HIV-related condition characterized, among other things, by numerous opportunistic infections is called the acquired immune deficiency syndrome (AIDS).
It is worth noting that not every infection with HIV progresses to AIDS. At the same time people with diagnosed AIDS are always HIV-positive.
Is it true that HIV-positive people live only a couple of years?
Though HIV can progress to AIDS and, as a result, lead to death, an average life expectancy of HIV-positive is almost the same as of healthy people. A recent study (its results were published in The British Medical Journal) found that an infected person who is at the moment 25 is expected to live up to 60 years with adequate treatment. According to another study, an average life expectancy of HIV-positive people is 71-75 years.
Can HIV/AIDS be transmitted through airborne route? Through drinking from the same glass with an infected person? Through kissing?
No, HIV can be transmitted only through vaginal, anal and oral sex, through direct blood contact with infected person (for example, while taking injection drugs) and from mother to baby (before or during birth, or through breast milk). Transmission of the virus through accidental puncture is very rare: the risk of getting infected with HIV (if an HIV-positive person used the needle) is 0,3%.
If a person in park accidentally steps on a needle that was used by an HIV-positive drug addict, can he or she get infected?
HIV can live only a couple of minutes outside a human body. If HIV lived outside a body for many hours or days (in its natural concentration), we would definitely note cases of household route infection, but we don’t.
Can HIV be transmitted through bug bites? For example, through mosquito bites? There’s blood...
HIV is a HUMAN immunodeficiency virus. It can live and copy itself only inside a human body. That is why insects can’t pass HIV. In addition, contrary to common myth, a human blood cannot be transmitted to other person’s blood flow with a mosquito bite.
Does an HIV-positive person always immediately infect a healthy person?
No, he or she doesn’t. There are people with natural immunity to HIV. Precisely, there are people whose cells mutated and didn’t let the virus in. Besides, a strong immunity of a healthy person is capable of resisting HIV.
Do HIV-positive women always give birth to infected children?
No, they don’t, but the risk is high. Although not every HIV-positive woman passes virus to her child, this transmission route is the main way children get HIV. 90% of children with HIV got it from their mothers. The virus can be transmitted before, during or after birth: during pregnancy, especially in the third trimester, fetus can be infected with HIV through placenta (15-25% cases of infected children); the virus can be transmitted to a baby during delivery through birth canal secretions (60-85%); also the virus can be passed to a breastfed baby through breast milk or mother’s blood (12-25%).
An appropriate treatment can prevent mother-to-child transmission of HIV. These are several measures that can reduce the risk of baby being infected:
- prescription of antiretroviral (ARV) drugs for mother during pregnancy&delivery and for a baby right after birth;
- appropriate labor management (if needed – elective caesarian section);
- formula feeding instead of breastfeeding.
Is there a cure for HIV?
There are no scientifically proven examples of complete cure of HIV: the disease is either terminal (at the AIDS stage) or chronic (with constant ARV treatment). But there are always exceptions from the rule. Timothy Ray Brown, who was given the nickname “The Berlin Patient”, improved his condition thanks to two stem cell transplantations from a donor with natural resistance to HIV. It happened in 2007-2008. Supposedly, genetically mutated cells “inhabited” Timothy’s immune system and let him discontinue ARV treatment. Though, the fact that “The Berlin Patient” lives a healthy live without ARV therapy doesn’t mean that HIV infection was completely cured. It could just hide and become less active.
The patient from Trenton, New Jersey (USA) could also stop taking ARV medications, but to do so he didn’t have to undergo through a difficult and risky operation (lethality during bone marrow transplantation is 30%). Instead he had his own genes improved by scientists: the patient’s leukocytes were removed and processed with a special technology in order to produce a protein eliminating CCR5 gene (mutation of this gene makes people resistant to HIV). The experiment turned out to be successful and the infected person could do without therapy. But the result was not 100% inspiring. The same manipulation with five other people’s genes was a disappointment. Probably, according to scientists, every other CCR5 gene from “The Trenton Patient” could have inherited mutation that made their task easier.
There are other examples: scientists managed to cure a newborn of HIV with the help of aggressive antiretroviral therapy that started the next day she was born. The girl was being treated only for 18 months. Now, when the girl is almost 3,5 years old, her blood tests don’t show traces of active virus. At the same time not all scientists agree that what happened was an actual full&irreversible cure of HIV. Some experts refer to low effectiveness of HIV-tests for people younger than 18 months (i.e. it is not clear if the child was infected), others have no doubt that the virus is still hidden in her body – they call the situation “a long-term remission” or “a functional cure”. And their doubts are easy to understand. Recently it was found that another experiment that allegedly led to the cure of two patients had failed. Two patients from Boston, just as Timothy Brown, underwent stem cell transplantation (though their donors were not resistant to HIV). For a period they could do without antiretroviral drugs, however, according to recent data, in their case the virus wasn’t beaten.