What is HIV?

HIV is short for Human Immunodeficiency Virus. HIV attacks the body's immune system, making it hard to fight off infections. HIV particularly attacks the white blood cells called CD4 cells, which sets the immune system in motion when infections enter the body. HIV infects CD4 cells and uses them to make new copies of HIV, which go on to, infect more cells. The lower a person's CD4 count, the weaker their immune system will be.

Find out about HIV statistics in the UK

What is AIDS?

AIDS stands for Acquired Immune Deficiency Syndrome. When a person's immune system has been damaged he or she is open to other illnesses, especially infections (e.g. tuberculosis and pneumonia) and cancers, many of which would not normally be a threat. Before effective treatments, if someone with HIV got one of these illnesses the person was said to have AIDS. However, it is no longer a widely used term. Doctors may instead call this 'late stage' or 'advanced HIV infection'.

How is HIV passed on?

For someone to become infected, a sufficient amount of HIV must get into his or her blood. The body fluids, which contain enough HIV to infect someone, are blood, semen, vaginal fluids including menstrual blood, and breast milk. Saliva, sweat and urine do NOT contain enough viruses to infect someone. HIV CANNOT pass through intact external skin, or through the air like a cold or flu virus.

The main routes of transmission in the UK are:

· Through sex without a condom - HIV can pass from one person to another through unprotected anal or vaginal sex. There is only a small risk of transmission through oral sex.

· Through injecting drug use - HIV can be passed on by using needles or syringes that someone with HIV has already used.

· From mother to baby - a pregnant woman may transmit the virus to her baby before or during birth, or HIV can be passed on during breastfeeding.

· Through organ transplant, blood transfusion or blood products - before it was known that donated blood might contain HIV, many people with haemophilia became infected through receiving contaminated blood products. However since 1985, all blood and tissue donations in the UK have been screened for HIV and all blood products are now treated to destroy any HIV, which may be present.

Find out about HIV statistics in the UK

Article continued on Page 2