Everything you need to know about HIV and AIDS including common symptoms and where to get tested.
HIV (human immunodeficiency virus) is a virus that attacks the body’s immune system and is most commonly caught by having unprotected sex, sharing injection needles, infected blood products or in extremely rare cases the infection of a baby by its mother.
There are still a huge number of misconceptions around HIV and AIDS, so Dr Roger Henderson sets the facts straight:
What is HIV?
HIV means ‘human immunodeficiency virus’. This is the virus that is the cause of AIDS and is in the group of viruses called retroviruses.
HIV first emerged as a threat to health in the early 1980s and it is now estimated there are around 22 million people on treatment for HIV around the world. Although effective treatment has now become available, the virus still remains a threat. The most recently available UK statistics show that:
- In the UK, the number of people who are living with HIV has doubled in the last decade and around 110,000 people living in Britain have the HIV virus.
- Around 10,000 people in the UK with HIV are unaware they have it.
- 98% of people diagnosed with HIV in the UK are on treatment, and 97% of those on treatment are virally suppressed which means they can’t pass the virus on. Of all the people living with HIV in the UK, 89% are virally suppressed.
- The number of people accessing specialist care for HIV has steadily grown over the last decade. From 2010 to 2019, the number of people accessing HIV care has increased by around 42%.
- More than two in five people accessing HIV care in 2019 were aged 50 or over and the number of people living with HIV aged 50 and over now matches that of the 35-49 years age group. This shows how effective treatment is helping people to live longer with HIV.
- A third of the British people who are living with HIV are women – which disproves the notion that ‘only men get it’. (The proportion of people accessing HIV care in 2019 who acquired HIV transmission through heterosexual sex is very similar to the proportion of people who acquired HIV through sex between men.)
- The majority of people accessing HIV care in 2019 acquired HIV through sexual transmission.
- Each year in the UK, almost 7,000 people are diagnosed as having HIV.
- While about 55 per cent of them are gay males, about 45 per cent are heterosexual men and women. Incidentally, gay women are no more likely than straight women to get HIV.
HIV common myths
Many people still believe the following myths that have become commonplace during the 35 years since HIV first emerged:
Can you tell if someone is HIV-positive by looking at them?
The great majority of people with HIV look perfectly normal.
Can you get HIV from straight sex?
Worldwide, vaginal intercourse is now the most common way of acquiring the virus.
Do only gay men get HIV?
As you can see from the figures above, large numbers of heterosexual men and women get HIV.
How does HIV infect people?
There are four main ways in which HIV can enter the body:
• During sex
Sexual transmission is the commonest way to pass the HIV virus on, with 9 in 10 cases occurring in this way. Vaginal and anal intercourse with an infected person is the commonest way of catching HIV with oral sex being a lower (but not negligible) risk. The majority of infections worldwide are now caused by vaginal intercourse with an infected person.
• Sharing injection needles
Intravenous drug users are at particular risk, if they use needles that have already been used by someone else and which therefore may be contaminated with the virus.
• Infected blood products
In some parts of the world blood intended for transfusion is still not tested for HIV. However, this is not the case in the UK as all blood products have been checked for HIV before being used since 1985.
• Infection of a baby by its mother
Effective modern treatments now mean that this risk of transmission can be as low as 1 in 100.
A tiny number of cases occur for other reasons, for instance as a result of organ donation or sperm donation from a person who is HIV-positive, though these occurrences are very unlikely in the UK.
How does HIV attack the human body?
HIV cannot live on its own in the environment. So, in order to survive, the virus has to attack other living cells and use their metabolism to make copies of itself. Unfortunately, HIV attacks some of the human cells that are vital to a healthy immune system, including the white blood cells (lymphocytes) known as T-helper cells or CD4 cells. HIV also multiples within CD4 cells and because it continually keeps changing its outer coat it is resistant to being destroyed by white blood cells.
What are the most common signs and symptoms of HIV?
At the start of HIV infection – the primary infection – there are two possible outcomes. Around 80 per cent of people have a short, flu-like illness that occurs one to six weeks after infection, with the three commonest symptoms being a high temperature, a sore throat and a blotchy red rash. After these symptoms settle, there may be no symptoms for several years.
Fewer people have a so-called ‘dumb’ infection, with no symptoms at all but even without any symptoms, you can still infect other people.
Around 80% of people have a short, flu-like illness that occurs one to six weeks after infection.
Six to 12 weeks after the infection, the white blood cells have produced so many antibodies against HIV that they can be measured by a blood test. If you have HIV antibodies in your blood, you are now HIV-positive (HIV+).
An infected person will probably feel well for a long time. But the infection is still active inside the body and the virus, which can infect and destroy new blood cells, is constantly being produced.
The number of T-helper cells in the blood will slowly be reduced and when, after a number of years, the immune system has been weakened, the infected person will start showing symptoms such as persistent swollen lymph glands, night sweats, mouth ulcers, tiredness and weight loss. Following this, AIDS can develop.
What is AIDS?
AIDS means ‘acquired immune deficiency syndrome’ and is used to describe the most advanced stage of HIV infection. It sets in when the HIV virus has killed so many T-helper cells that the immune system is no longer able to recognise and react to attacks from everyday infections. Someone with AIDS usually has one or both of the following:
- Opportunistic infections such as severe thrush, TB, pneumocystis pneumonia, CMV and toxoplasmosis.
- A very low CD4 T cell count, of below 200.
HIV may also attack the nervous system, possibly causing dementia. And it may affect the skin, on which small tumours develop. This condition is known as Kaposi’s sarcoma.
A number of different symptoms can occur in people who have AIDS:
- Weight loss and body wasting
- Repeated infections that do not respond to treatment
- Swollen lymph nodes
- Night sweats
- Outbreaks of previous infections that have remained dormant (herpes, toxoplasmosis, shinglesand other conditions)
- So-called ‘opportunistic infections’ – serious infections by micro-organisms of the type normally defeated by the immune system. These in turn could lead to a number of related illnesses, such as canceror dementia. Tuberculosis may also occur.
In the end, the disease can become so serious that the infected patient dies. However these days, because of modern treatment many people now survive who would otherwise have died.