Medical information – HIV

What is the Human Immunodeficiency Virus?

The human immunodeficiency virus, abbreviated HIV, belongs to the group of small RNA-viruses and is member of the group Retro viruses. Two types of this virus are described: type 1 (HIV-1) and type 2 (HIV-2). HIV can infect the human body. HIV causes AIDS and attacks the immune system by destroying CD-4 cells. This type of white blood cells is crucial to fight infections. When the immune system is broken down, the body is susceptible to life-threatening conditions, such as infections or cancer.

How common is HIV?

HIV infections are relatively rare, but the consequences are huge. In 2012, an estimated 98,400 people were living with HIV in the UK. Of these, 22% were unaware of their HIV infection. HIV is usually transmitted by sexual contact. The number of HIV-infected is for one half among heterosexuals, the other half of the HIV-infected is men who have sex with men (MSM). Gay men and bisexual men are a large risk group; the prevalence of the virus is also the most amongst them. Research has shown that the use of condoms reduces the risk of transmitting an HIV infection, but it can not be completely avoided.

The effect of human immunodeficiency virus in the body

HIV is the causative agent of AIDS. HIV can therefore be detected in all cases of AIDS. However, not every HIV infection immediately leads to AIDS. A clinically latent infection, also referred to as asymptomatic infection, is usually free of symptoms until the development of AIDS.

How should we imagine that?

After an infection of the body with HIV, the immune system will in most people fight back against the virus. In the first phase of the infection 70%, from the people with HIV, exhibits influenza-like symptoms. Two to four weeks after exposure to the virus, the immune system fights back with antibodies. In this period, the HIV levels in the blood drop very strong, and the number of CD4 cells rise again. However, the subsequent immune response of the body has only partial success. The virus can then stay months, sometimes years in the body without us noticing. During the time that the virus resides in the body, the presence can be demonstrated: for example, with a test for the detection of antibodies against the HIV virus (HIV-home test).

Can the virus also go away?

HIV invades, after infection of the body, in CD4-cells and macrophages. For some years, there may be a clinically latent situation. During this period, however, there is intense viral replication and immune response against HIV-infected cells. A seemingly balance between production of HIV and CD4 cells is present in this phase. Due to the continuous replication of the virus mutants arise which the immune system at a given moment can no longer fight. The number of CD4 cells in the blood reduces and the immune system is malfunctioning. The result is a cellular immune suppression, which leads to a number of opportunistic infections and cancer. Finally, the patient dies from the effects of these additional diseases.

Progression to AIDS?

AIDS can manifest itself in many forms. Due to the failure of the immune system arises a variety of diseases. In the foreground are opportunistic infections, neurological diseases and malignant tumours. At which time there is AIDS precisely depends on the definition used. In Europe, a CD4 cell count of less than 200 cells/mm³ without clinical symptoms is not to counted as AIDS, in contrast to the CDC definition in the United States. The divergent definition has to do with among other the financing of the treatment in the United States.

Some examples of opportunistic infections are:

  • candida esophagitis
  • tuberculosis
  • pneumonia, among that Pneumocystis carinii
  • herpes simplex virus infections
  • human herpes virus
  • 8 associated Kaposi’s sarcoma

Examples of neurological disorders include:

  • peripheral neuropathy
  • HIV encephalopathy (AIDS dementia complex)

Examples of malignant tumors are:

  • cervical cancer
  • lymphatic cancer

What can you do with an HIV-infection?

Chemoprophylaxis is recommended after exposure if there is an increased risk of HIV infection. The potential toxicity of treatment should be weighed against the actual risk of HIV infection. Chemoprophylaxis occurs with combination therapy. One should start as soon as possible with post-exposure prophylaxis (PEP), preferably within two hours, with a maximum of 72 hours after acute exposure. Chemoprophylaxis after sexual exposure is recommended in the UK in particular with accidental unsafe anal and/or vaginal sex with a known HIV positive source. In the STD clinic, if necessary, medication can be to prevent HIV infection. This is known as PEP. Read more about drug treatment PEP.

Can a HIV-infection be prevented?

In order to reduce the likelihood of an HIV infection the use of a condom during intercourse is recommended. Moreover, condoms provide protection against several sexually transmitted diseases (STDs). However, condoms can not prevent the transmission of HIV during sexual contact to 100%. Continue to take measures to prevent possible contamination of others

Human Immunodeficiency Virus

It is very difficult to see a virus through a microscope. They are far too small. A white blood cell of the immune system is approximately 6-15 µm or 6-15 times a thousandth of a millimeter. The HIV virus is much smaller than a cell, ie 100 times smaller (= 120 nm). A virus fits easily into a cell. The “photograph” of such a small particle is not so easy. That is why often you see the same picture of the virus: a kind of beads with vesicles, sometimes in black and white, sometimes coloured. It is a complex virus. A football has 32 patches (20 white and 12 black), alternating with pentagons and hexagons. An HIV virus has 20 planes of triangles. There are two proteins required. This is called ‘capsule’ or ‘coat’. (Inside the capsule of the virus is the virus RNA with a few proteins). Retroviruses such as HIV have an envelope. This makes them poorly resistant to drought, except in a protein-rich environment such as blood. In liquid plasma, at room temperature, the virus is more than two weeks infectious.

Vaccination or medication?

There is no curative therapy against HIV. However, several remedies are available, which inhibit the production of new virus so that fewer new cells are infected. The current drugs are reverse transcriptase inhibitors, protease inhibitors, fusion inhibitors (only one remedy on the market, are used only in exceptional situations, such as multi-resistance) and integrase inhibitors. Starting antiretroviral therapy depends on the clinical picture, the CD4 cell count and viral load. The decision to start therapy is also influenced by the unknown long-term effects of antiretroviral therapy and the fact that motivation and compliance are necessary. The combination should avoid prematurely becoming resistant to HIV inhibitors. The aim of treatment is to slow progress which is delayed to the AIDS virus replication: reducing the number of opportunistic infections and postpone death.

Antiretroviral therapy has side effects. Depending on the drugs used are common side effects: loose stools, nausea, anemia, neuropathy, liver enzyme levels, allergic reactions, pancreatitis.

In addition to anti-retroviral therapy is also prescribed for antimicrobial prophylaxis reduced immunity for the prevention of opportunistic infections for example Pneumocystis carinii.

Initiated treatment should lead to an undetectable viral load (<50 copies per ml) after six months. One and three months after starting treatment should be clear that the therapy is effective (decrease viral load). If this is not the case then, preceded by discussing the compliance to the medication intake, the determination of the plasma level of HIV-RNA, and optionally a viral resistance determination, the therapy has to be adjusted.

Until now there is no cure for AIDS found. There are so-called AIDS developed inhibitors, which can importantly delay the course of the disease.

You have tested positive. And now?

If you have tested positive for antibodies against the HIV-1 virus, you will have to directly contact your family doctor or a internal medicine infectiologist or a medical specialist to carry out a blood test.

Whom should I tell that I have HIV?

All of your past sexual partners should be told so they can get counselling and be tested. It is also important to tell your current and future partners so they can make their decision. If you have shared needles, syringes or drug equipment with anyone, they should also be informed.

Inform your doctor and other health care providers.

You may want to tell your family and friends that you have HIV. They may be a support for you. The decision is up to you! Before you tell someone that you have HIV, it may help to talk to your doctor or counsellor. They can help you to decide whom you want to tell and how you want to tell them.

You do not have to tell your boss or people you work with that you have HIV. Under the Human Rights Act you cannot be fired for being HIV positive.


Should you have any questions, please don’t hesitate to have a look in our FAQ or contact us! You can reach us by mail or by phone. Your questions will be answered by our infectiologist and/or microbiologist.


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The helpline is open weekdays 10am to 4pm, and until 8pm on Thursdays. Positively UK provides peer support to people living with HIV and services include advocacy, information on treatment, and crèche facilities. For more information, see