Sexual health: HIV and AIDS

Human immunodeficiency virus, or HIV, is the virus that causes acquired immune deficiency syndrome (AIDS). The virus weakens a person's ability to fight infections and cancer. People with HIV are said to have AIDS when they develop certain infections or cancers or when their CD4 count is less than 200. CD4 count is measured with a blood test taken by your doctor or at an HIV clinic.

Having HIV does not always mean that you have AIDS. It can take many years for people with the virus to develop AIDS. HIV and AIDS cannot be cured. Although it is likely that people with AIDS will one day die from an AIDS-related illness, there are ways to help people stay healthy and live longer.

How does HIV and AIDS cause illness?

HIV attacks and destroys a type of white blood cell called a CD4 cell. This cell's main function is to fight disease. When a person's CD4 cell count gets low, they are more susceptible to illnesses.

What Is AIDS?

AIDS is the final stage of HIV infection. When the immune system’s CD4 cells drop to a very low level, a person's ability to fight infection is lost. At this stage, there are several conditions that occur in people with HIV infection with this degree of immune system failure - these are called AIDS defining illnesses.

How do people get HIV?

In the UK, it is estimated there are more than 77,000 people living with HIV. Experts predict that 28% of people who have HIV are unaware they have the condition. In 2008, there were more than 7,000 new cases of HIV diagnosed.

A person gets HIV when an infected person's body fluids (blood, semen, fluids from the vagina, or breast milk) enter his or her bloodstream. The virus can enter the blood through linings in the mouth, anus or sex organs (the penis and vagina), or through broken skin.

Both men and women can spread HIV. A person with HIV can feel fine and still give the virus to others. Pregnant women with HIV also can give the virus to their babies.

Common ways people get HIV:

• Sharing a needle to take drugs
• Having unprotected sex with an infected person.

You cannot get HIV from:

• Touching or hugging someone who has HIV/AIDS.
• Public toilets or swimming pools.
• Sharing cups, utensils, or telephones with someone who has HIV/AIDS.
• Insect bites.