:: HIV and AIDS - The Basics ::
The Human Immunodeficiency Virus (HIV) is transmitted through body fluids, in particular blood, semen, vaginal secretions and breast milk.
Transmisson of Infection- Unprotected sexual intercourse with an infected partner
- Sharing needles when injecting or other use of contaminated injection or other skin-piercing equipment
- Blood and blood products, for example, infected transfusions and organ or tissue transplants
- Transmission from infected mother to child inutero or at birth and breastfeeding
HIV is not transmitted by....- Casual physical contact
- Coughing, sneezing or kissing
- Sharing toilet and washing facilities
- Using eating utensils or consuming food and beverages handled by someone who has HIV
- Mosquitoes or other insect bites
What happens when HIV is contracted?
HIV weakens the human body's immune system, making it difficult to fight infection. Treatments exist which can prevent the onset of AIDS (the term AIDS is now very rarely used. It is more usual to talk of late-stage or advanced HIV infection) and although there are side effects, a person can lead a healthy, active life with a long life expectancy if they respond well to treatment. However, they can still transmit the infection to others.
Early symptoms of advanced HIV infection. - Chronic fatigue
- Diarrhoea
- Fever
- Mental changes such as memory loss
- Weight loss
- Persistent cough
- Severe recurrent skin rashes
- Herpes and mouth infections
- Swelling of the lymph nodes
Opportunistic diseases such as cancers, meningitis, pneumonia and tuberculosis may also take advantage of the body's weakened immune system. Is there a cure?
Treatments exist which can slow the advancement of HIV and allow periods of illness to be followed by periods of remission. However, there is no cure. Research is currently under way into vaccines, but none is viable as yet.
How does HIV transmission occur?
HIV is a fragile virus, which can only survive in a limited range of conditions. It can only enter the body through naturally moist places and cannot penetrate unbroken skin. Prevention therefore involves ensuring that there is a barrier to the virus, for example condoms, and that skin-piercing equipment is not contaminated
. :: HIV & AIDS The Difference :: HIV
HIV stands for Human Immunodeficiency Virus.
HIV infects and gradually destroys an infected person's immune system, reducing their protection against infection and cancers.
Initially, someone living with HIV may show no symptoms of HIV infection as their immune system manages to control it. However, in most cases their immune system will need help from anti-HIV drugs to keep the HIV infection under control. These drugs do not completely rid the body of HIV infection.
AIDS
AIDS is short for Acquired Immune Deficiency Syndrome.
AIDS is not a single disease or condition. Instead, it is a term that describes the point when a person’s immune system can no longer cope because of the damage caused by HIV and they start to get one or more specific illnesses.
People do not actually die from AIDS; they die from the cancers, pneumonia or other conditions that may take hold when their immune system has been weakened by HIV.
The term AIDS is now very rarely used. It is more usual to talk of late-stage or advanced HIV infection.
Main sources of infection
The body fluids that contain enough HIV to infect someone are:
- seminal fluid
- vaginal fluids, including menstrual fluids
- breast milk
- blood
- the mucous found in the rectum
- pre-cum (the fluid that the penis produces for lubrication before ejaculation)
Other body fluids, like saliva, sweat or urine, do not contain enough of the HIV virus to infect another person.
So the main ways that HIV can be transmitted are:
HIV testing
HIV is tested for via a blood test. The test doesn't look for the virus itself but for antibodies to the virus. Antibodies are made in the blood when an infection has got into the body.
It can take up to three months after infection with HIV before the antibodies show up in the blood. These three months are called the window period. A test done before these three months are over isn't reliable because a blood test may find no antibodies and so the client will appear free of HIV, even though the reality is that they may have been infected (and could pass HIV on to others).
:: Pregnancy, Birth & Treatment :: Factors that increase the risk
A child is more likely to contract HIV from its mother if she;
- has advanced HIV infection or AIDS;
- has high viral load or a low CD4 count;
- her waters break at least four hours before delivery;
- has a vaginal delivery (as opposed to a planned caesarean section); the labour is difficult, requiring episiotomy or forceps;
- has a genital infection (e.g. a sexually transmitted infection, such as chlamydia);
- uses illicit drugs during pregnancy; or she breast-feeds.
Becoming infected with HIV during pregnancy is also likely to increase the risk.
Breast-feeding
The risk of infection is roughly doubled to around 1 in 3 if the mother breast-feeds her child, and so women are advised not to if there is a safe alternative to breast milk.
Treatments to prevent mother to baby transmission: AZT and nevirapine
The anti-HIV drug AZT (zidovudine) has been shown to reduce the risk of transmission. In one study, pregnant women received AZT tablets during the last six months of pregnancy and intravenous AZT during labour and delivery, plus AZT syrup for their babies for the first six weeks after birth. They were also advised not to breast-feed.
These women were much less likely to transmit HIV to their babies than women who did not take AZT. The use of AZT during pregnancy has reduced transmission rates to very low levels in the UK, parts of Europe and the US.
Studies in resource limited countries have shown that even when AZT is started later in pregnancy, or around the time of delivery, this can still reduce the risk of transmission by about half.
AZT alone is inadequate treatment for the woman herself, and could limit her future treatment options if she becomes resistant to the drug. Studies so far suggest this does not happen often when AZT is used in pregnancy only. AZT may not be quite as effective at reducing mother-to-baby transmission in a woman who has already taken AZT before pregnancy.
More recently trials conducted in Africa have found that a single dose of nevirapine given to a mother during labour and a single dose given to the baby after delivery can dramatically reduce the chances of a mother passing on HIV to her baby. There are however concerns about the possible emergence of nevirapine resistance, and if a woman is receiving HAART she should not be given single-dose nevirapine.
Caesarean Section delivery (LSCS)
The risk of transmission is reduced if the baby is delivered by planned caesarean section, rather than by vaginal delivery. This is called an ‘elective caesarean’, and is scheduled for the 38th week of pregnancy, or performed sooner if labour begins early.
Research suggests that anti-HIV therapy during pregnancy plus planned caesarean delivery may reduce the risk of transmission to as low as 2% (1 in 50). Caesarean delivery itself can carry some risk for the mother.
If a woman has an undetectable viral load at the time of delivery, she has the option of having a planned vaginal delivery.
Treatment during pregnancy
Women who become pregnant when their CD4 count is high and viral load is low are less likely to pass on HIV to their child. These women may not require treatment themselves, and so they are advised to begin AZT some time after week 14 of their pregnancy.
Pregnant women are encouraged to take the treatment which they require regardless of their pregnancy. (An exception is the anti-HIV drug efavirenz, which is not recommended in pregnancy.) This means that antiretroviral therapy, considered standard treatment for adults with HIV, are now more widely used by women who become pregnant. There is no information about whether these are more effective than AZT alone in preventing HIV transmission, but it is assumed that they could be because they are much more able to reduce the mother’s viral load.
Women who conceive whilst on treatment
During the first 14 weeks of pregnancy, the fetus is most vulnerable to any toxic effects of drugs. Taking anti-HIV drugs during this time may increase the risk of birth defects. However, stopping treatment may increase the risk of transmission, as viral load would be expected to rise, and so it is recommended that women continue their treatment throughout their pregnancy.
Side-effects in the baby
To date, children born to mothers exposed to AZT in pregnancy show no increased risk of birth defects or growth problems, though their continued monitoring remains important. Much less is known at the moment about the safety of other anti-HIV drugs. One small study of pregnant women taking AZT and 3TC, with or without protease inhibitors, found a high rate of premature births, and a small number of abnormalities at birth.
However, other studies have reported no increase in premature delivery or congenital abnormalities and a large American study published in 2002 found that protease inhibitors did not increase the risk of having a premature or low birth-weight baby and that smoking, drinking or using drugs during pregnancy were the causes of premature delivery and other birth defects.
HIV worldwide
The
Joint United Nations Programme on HIV/AIDS (UNAIDS) has estimated that there are up to 40 million people living with HIV in the world. Seventy percent of them live in sub-Saharan Africa.
In the three worst affected countries - Botswana, Swaziland and Zimbabwe - about one in three people is living with the virus. In comparison, there is no country outside Africa where more than one in 20 people is living with the virus.
However, although Africa continues to be the worst-affected region, many of the countries with the highest rates of growth are outside Africa. These include India, China, Russia and most of the other former Soviet states.
HIV is not passed on easily from one person to another, especially compared to other viruses. That's because the HIV virus is present in body fluids. So for HIV to be passed on, the body fluids of someone who is already infected have to get into an uninfected person's body and then into their bloodstream.
:: References :: http://www.aidsmap.com/en/default.asp http://www.nat.org.uk/ http://www.tht.org.uk/ http://www.who.int/hiv/en/ Books