SOME INFORMATION ON HIV / AIDS

What Are HIV and AIDS?
How Does HIV Transmission Happen
Sexual Transmission
Effectiveness of Condoms and How to Use Them
How is HIV Transmitted By Infected Blood?
AIDS Vaccine

What are HIV and AIDS

HIV is a virus. Illnesses caused by a virus cannot be cured by antibiotics. (Although medicines may help to reduce the symptoms). People who have a virus - such as a cold- usually get better after a few days or weeks because the white blood cells of the immune system - which are responsible for fighting diseases - successfully overcomes them. When a person is infected with HIV the immune system tries to fight off the virus and does make some antibodies, but these antibodies are not able to defeat HIV.

Many people do not feel ill at all when they are first HIV infected. They may have no symptoms for a long time. They have not yet got AIDS. HIV acts by gradually destroying the immune system of the infected person. After about 5 to 10 years (although much earlier in some cases) the immune system becomes so weak that it cannot fight off infections as it used to. Eventually the infected person may lose weight and become ill with diseases like persistent severe diarrhoea, fever, or pneumonia, or skin cancer. He or she has now developed AIDS.

HIV Structure

This picture shows the structure of the Human Immunodeficiency Virus (HIV).

HIV Replication

This picture is of a cell producing HIV. HIV has a diameter of 1/10,000 of a millimetre.
HIV belongs to a class of viruses called retroviruses, which have genes composed of ribonucleic acid (RNA) molecules. Retroviruses, like all viruses, can only replicate within a living host cell because they contain only RNA and they do not contain DNA. In addition, retroviruses use RNA as a template to make DNA.
Infection begins when an HIV particle encounters a cell with a surface molecule called CD4.

At the moment, there is no cure for HIV or for AIDS but today there are medical treatments that can slow down the rate at which HIV weakens the immune system. There are other treatments that can prevent or cure some of the illnesses associated with AIDS. As with other diseases, early detection offers more options for treatment and preventative care.

AIDS stands for acquired immunodeficiency syndrome. An HIV-infected person receives a diagnosis of AIDS after developing one of the CDC-defined AIDS indicator illnesses.

How does HIV transmission happen?

HIV is found in body fluids such as blood, semen, vaginal fluids and breastmilk. It is transmitted in the following ways:

through sexual intercourse between a man and a woman or between two men;

through infected blood - for example through contaminated blood transfusions or unsterilised needles and syringes. ( In most places today blood transfusions are completely safe because the blood is tested for HIV before it is used to treat patients);

from an infected mother to her baby while it is still in the womb or during childbirth or during breastfeeding.

HIV does not spread through "casual" everyday contact between people. It is not transmitted by coughing, or sneezing, or by touching or hugging someone who has the virus. It is not spread in air, water or in food, or by sharing cups, bowls, cutlery,clothing, or toilet seats. And HIV is not transmitted by biting insects such as mosquitoes, because the quantity of blood on their mouthparts is too minute.

Sexual transmission

In 8 out of 10 cases HIV is transmitted during sex between a man and a woman or between two men. The virus is passed on when infected blood, semen, or vaginal fluids from one partner enters the body of the other partner through the very thin skin of their sex organs, mouth or anus, or through sores or cuts on their mouth, hands or body. Dry sex increases the risk of HIV transmission because friction can cause sores in the vaginal wall. If instead of having sexual intercourse a couple enjoy oral sex, HIV could still pass into any sores or cuts on the lips or mouth. Oral sex can be made safe by the man using a condom.

Effectiveness of condoms and how to use them

Condoms are classified as medical devices.

The proper and consistent use of condoms when engaging in sexual intercourse--vaginal, anal, or oral--can greatly reduce a person's risk of acquiring or transmitting sexually transmitted diseases, including HIV infection.

Women may wish to consider using the female condom when a male condom cannot be used.

For condoms to provide maximum protection, they must be used consistently (every time) and correctly. When condoms are used reliably, they have been shown to prevent pregnancy up to 98 percent of the time among couples using them as their only method of contraception. Similarly, numerous studies among sexually active people have demonstrated that a properly used latex condom provides a high degree of protection against a variety of sexually transmitted diseases, including HIV infection.

Condoms can only work well if they do not come off or split. If they are stored and used carefully, this will only very rarely happen. Both men and women should know how to use one.

Store condoms in a cool place, away from heat or sunshine which can damage rubber;

Use a new condom each time, and use it only once. Check the date on the packet, and that the packet is not damaged, crushed or torn;

Open the packet carefully, so the condom is not damaged. Check that the condom is neither brittle nor sticky. If it is, throw it away and use another one;

When having sex, wait until the penis goes hard, but put the condom on before the penis touches the other person's sex organs, anus or mouth;

Check that the condom is the right way up, with the roll on the outside;

With one hand, pinch the top of the condom to press out the air bubble;

With the other hand, roll the condom right down to the base of the penis, to the pubic hair;

If a lubricant is used (and this can help to prevent the condom from splitting), use a water based one (KY jelly), not oils, fat or cream which can damage the rubber;

After sex, hold the condom in place and withdraw the penis from the vagina, anus or mouth while it is still hard;

Take the condom off carefully, making sure that no semen is spilled, wrap it up and dispose of it carefully in a toilet or latrine.

With anal sex there is a greater risk that a normal condom will split, so a special thicker condom should be used, together with lots of a water based lubricant. Never re-use a condom.

How is HIV transmitted by infected blood?

HIV can be transmitted with:

Contaminated instruments used to pierce the skin (injections, circumcision, scarrification, ear piercing, tatooing, acupuncture);

Blood transfusions

Sharing needles: if people inject themselves - or someone injects them - with medicines or drugs using a needle or syringe which has been used by someone else, who might have HIV, they will be at high risk of getting HIV themselves. It is not possible to tell if a person has HIV. They might not know it themselves.

AIDS vaccine

The development of an AIDS vaccine is also affected by the range of virus subtypes as well as by the wide variety of human populations who need protection and who differ, for example, in their genetic make-up and their routes of exposure to HIV.
Inevitably, different types of candidate vaccines will have to be tested against various viral subtypes in multiple vaccine trials, conducted in both high-income and developing countries.

In the long term, a safe, effective and affordable preventive vaccine against HIV is the best hope of bringing the global epidemic under control. However, it would be a mistake to think that the development of such a vaccine will be quick or easy or to expect that once a vaccine is available it will replace other preventive measures.

Scientists are working to understand the kind of immunity a vaccine would have to induce in order to protect someone against HIV infection. The information that they generate is in turn being used by the pharmaceutical and biotechnology industry to develop "candidate vaccines" to be tested in HIV-negative human volunteers. The first human trial of an HIV-preventive vaccine was conducted in 1987 in the United States.

Since then, more than 30 small-scale trials have been conducted, including 12 in developing countries (Brazil, China, Cuba, Thailand and Uganda). These trials, carried out with the participation of more than 5000 healthy volunteers have shown that the candidate vaccines are safe and that they induce immune responses that could potentially protect people against HIV infection.