Biology

5.3 - Viral Diseases

6 min

What viruses are

MeaslesOutside your course

HIV and AIDS

Tobacco mosaic virusOutside your course

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HIV and AIDS

HIV (human immunodeficiency virus) attacks the immune cells - a type of white blood cell.
There is no cure, but the infection can be controlled with antiretroviral (antiviral) drugs, which stop the virus replicating inside the body.

How HIV is spread

Through sexual contact.
Through the exchange of body fluids such as blood - for example when drug users share needles.

Its spread can be reduced by using a condom during sex, and by people who inject drugs not sharing needles.

The stages of infection

At first HIV causes a flu-like illness for a few weeks.
The person then often feels well for several years while the virus attacks the immune cells.
If the immune system becomes so badly damaged that the body can no longer fight off other infections or cancers, the person has late-stage HIV infection, or AIDS (acquired immune deficiency syndrome).
With a weakened immune system, a person with AIDS becomes vulnerable to other infections such as tuberculosis and pneumonia.

key terms

TermDefinition

HIVA virus that attacks the body's immune cells and can eventually lead to AIDS if it is not treated.

AIDSThe late stage of HIV infection, when the immune system is so badly damaged that the body can no longer fight off other infections.

Antiretroviral drugsMedicines that control an HIV infection by stopping the virus from replicating.

end of notes

Key points to remember

HIV and AIDS

HIV (human immunodeficiency virus) attacks the immune cells - a type of white blood cell.

There is no cure, but the infection can be controlled with antiretroviral (antiviral) drugs, which stop the virus replicating inside the body.

How HIV is spread

Through sexual contact.

Through the exchange of body fluids such as blood - for example when drug users share needles.

Its spread can be reduced by using a condom during sex, and by people who inject drugs not sharing needles.

The stages of infection

At first HIV causes a flu-like illness for a few weeks.

The person then often feels well for several years while the virus attacks the immune cells.

If the immune system becomes so badly damaged that the body can no longer fight off other infections or cancers, the person has late-stage HIV infection, or AIDS (acquired immune deficiency syndrome).

With a weakened immune system, a person with AIDS becomes vulnerable to other infections such as tuberculosis and pneumonia.