HIV stands for Human Immunodeficiency virus that attacks the immune system, which is our body’s natural defense against illness. The virus destroys a type of white blood cell in the immune system called a T-helper cell, and makes copies of itself inside these cells. T-helper cells are also referred to as CD4 cells.
As HIV destroys more CD4 cells and makes more copies of itself, it gradually breaks down a person’s immune system. This means someone living with HIV, who is not receiving treatment, will find it harder and harder to fight off infections and diseases.
If HIV is left untreated, it may take up to 10 or 15 years for the immune system to be so severely damaged it can no longer defend itself at all. However, the speed HIV progresses will vary depending on age, health and background.
Around one to four weeks after becoming infected with HIV, some people will experience symptoms that can feel a lot like flu. This may not last long (a week or two) and you may only get some of the flu symptoms – or none at all. Experiencing these symptoms alone is not a reliable way of diagnosing HIV. You should always visit your doctor if you are worried you have been at risk of HIV infection, even if you don’t feel unwell or have any of the following symptoms. They can then arrange for you to have an HIV test.
These symptoms can happen because your body is reacting to the HIV virus. Cells that are infected with HIV are circulating throughout your blood system. Your immune system, in response, tries to attack the virus by producing HIV antibodies. This process is called seroconversion. Timing varies but it can take up to a few months to complete.
It may be too early to get an accurate HIV test result at this stage (depending on the type of HIV test, it can take anything from a few weeks to a few months for HIV to show up), but the levels of virus in your blood system are very high at this stage.
Once the seroconversion stage is over, many people start to feel better. In fact, the HIV virus may not reveal any other symptoms for up to 10 or even 15 years (depending on age, background and overall health). However, the virus will still be active, infecting new cells and making copies of itself. Over time this will cause a lot of damage to your immune system.
By the third stage of HIV infection there has been a lot of damage to your immune system. At this point, you are more likely to get serious infections or bacterial and fungal diseases that you would otherwise be able to fight off. These infections are referred to as ‘opportunistic infections’.Symptoms that you may have during this time can include:
It’s important to understand that HIV and AIDS are not the same thing. AIDS is not a virus or disease in its own right - it is a particular set of symptoms. If a person develops certain serious opportunistic infections or diseases (as a result of damage to their immune system from advanced stage 3 HIV infection), they are said to have AIDS. There isn’t a test for AIDS and you can’t inherit it. If you have advanced HIV (with AIDS-defining symptoms), it is really important to get the right treatment as soon as possible. With treatment it is still possible to recover from AIDS-related infections and diseases and bring HIV under control. The earlier you have HIV diagnosed, and start treatment, the better your likely long-term health.
Despite what you may have heard, there are only a few ways you can get HIV. Here, we explain the ways you can get it and how to protect yourself from HIV infection.
HIV lives in the following bodily fluids of an infected person:
• blood • semen and pre-seminal fluid (“pre-cum”) • rectal fluids/anal mucous • vaginal fluids • breast milk.
To get infected, these bodily fluids need to get into your blood through a mucous membrane, breaks in the skin (like cuts), or be injected directly into your bloodstream.
A person living with HIV can pass the virus to others whether they have symptoms or not. People with HIV are most infectious in the first few weeks after infection.
Having unprotected sex (sex without a condom) with someone who has HIV.
Sharing needles, syringes or other equipment used to prepare and inject drugs with someone who has HIV.
A mother infected with HIV can pass the virus to her baby via her blood during pregnancy and birth, and through her breast milk when breastfeeding.
Receiving blood transfusions, blood products, or organ/tissue transplants that are contaminated with HIV. This risk is extremely small because blood products are test for HIV first.
Some people wrongly believe that HIV can be spread by the air (even though HIV can’t survive outside the body) and other ways such as by touching toilet seats or from mosquito bites.
There are a number of ways you can protect yourself from HIV, including:
• using a condom every time having sex. you have vaginal, anal or oral sex • avoiding sharing needles, syringes and other injecting equipment with anyone if you take drugs • taking HIV treatment if you are a new or expectant mother living with HIV, as this can dramatically reduce the risk of passing HIV to your baby during pregnancy, childbirth and breastfeeding • asking your healthcare professional if the blood product you are receiving (blood transfusion, organ or tissue transplant) has been tested for HIV • taking precautions if you are a healthcare worker, such as wearing protection (like gloves and goggles), washing hands after contact with blood and other bodily fluids, and safely disposing of sharp equipment.
Understanding how HIV infects the body is important to help explain how HIV drugs work to treat the virus. The science behind the virus and the HIV life cycle help put wider prevention, treatment, and general HIV awareness into context.
The HIV virus attacks a type of white blood cell called T-helper cells (also called CD4 cells). These cells are important when it comes to having a healthy immune system as they help us fight off diseases and infections.
HIV cannot grow or reproduce on its own. Instead, it makes new copies of itself inside T-helper cells. This damages the immune system and gradually weakens our natural defences. This process of infected T-helper cells multiplying is called the HIV life cycle.
How quickly the virus develops depends on your overall health, how early you are diagosed and started on treatment, and how consistently you take your treatment. It’s important to know that antiretroviral treatment will keep the immune system healthy if taken correctly, preventing the symptoms and illnesses associated with AIDS developing.
There are several steps in the life cycle of HIV that can happen over many years. Antiretroviral treatment works by interrupting the cycle and protecting your immune system. There are different drugs offered depending on the particular stage of the HIV life cycle.
Understanding the HIV life cycle helps scientists to know how to attack the virus when it is weak and reduce its ability to multiply. Drug resistance means a person’s HIV treatment no longer prevents the virus from multiplying. This usually happens if treatment has not been taken correctly, allowing the virus to mutate.
First, the HIV virus attaches itself to a T-helper cell and releases HIV into the cell.
Drugs that can stop this part of the process are called fusion or entry inhibitors.
Once inside the cell, HIV changes its genetic material so it can enter the nucleus of the cell and take control of it.
Drugs that can stop this part of the process are called NRTIs (nucleoside reverse transcriptase inhibitors), NNRTIs (non-nucleoside reverse transcriptase inhibitors) and integrase inhibitors.
The cell then produces more HIV proteins that can be used to produce more HIV.
New HIV particles are then released from the T-helper cell into the bloodstream. These are now ready to infect other cells and begin the process all over again.
Drugs that can stop this part of the process are called protease inhibitors.
Antiretroviral treatment (or ART for short) uses a number of different HIV medicines to treat HIV infection. By combining different drugs that target different steps in the HIV life cycle ART is now very effective at preventing HIV from multiplying, and enables people who are on treatment to live longer, healthier lives.