HIV is a virus spread by sexual contact or by exchanging
bodily fluids like blood e.g. when two people share the same needle in
drug taking or sexual intercourse - semen and vaginal fluids.
(A sexually transmitted infection/disease can be defined as an
infection/disease that is transmitted via body fluids through sexual
(HIV is described as sexually transmitted infection/disease, STI/STD)
(An STI can be caused by a bacteria, fungus,
protist or virus)
The HIV virus attacks white blood cells, an
important part of the body's defence system of the blood.
It reduces the number of lymphocytes, a type of white
blood cell that helps your immune system fight infections such
as pathogens like viruses and bacteria and reduces the
ability to produce antibodies.
For more details see
The body's mechanisms of
Usually, initially, the HIV infected person experiences
symptoms for a few weeks but then no other symptoms may be
experienced for several years. Some people never exhibit flue-like
The virus enters the lymph nodes and attacks
some of the white blood cells of the immune system.
Antiretroviral drugs are prescribed
to inhibit the virus from entering the lymph node tissues which
are rich in lymphocytes - essential component of the body's
If treatment with antiretroviral drugs is
not successful, the virus enters the lymph nodes and attacks the
body's immune cells.
If diagnosed in time, HIV can be controlled with antiretroviral
drugs that stop the HIV virus replicating in the body.
The HIV virus attacks some of the types of white blood cells,
kills them and
so damaging part of the bodies immune system.
This means the body's defences against other infections,
the immune system, is
severely weakened and may not be able to cope, including an
increased risk of cancer.
AIDS sufferers are also much more
susceptible to other communicable diseases like colds and flue
and human papilloma virus (HPV).
At this advanced stage, when your body is struggling to cope
with any infection at all, HIV leads to 'late stage HIV infection' known as
Acquired Immune Deficiency Syndrome
Since HIV prevents the immune system from
working properly, the body is extremely vulnerable to
infection from any other pathogen - an unfortunate 'knock
on' effect because the person's immune system further
deteriorates and eventually fails to fight off an infection - an
extremely dangerous situation.
e.g. the bacteria that cause the
communicable disease would normally
be destroyed by the body's immune system before symptoms
However, the immune system of someone infected with the
HIV virus are much more likely to display symptoms of
tuberculosis and the disease may develop very rapidly - recovery
is much more difficult and the outcome can be serious e.g.
persistent coughing and lung damage and possibly death.
Prevention of infection and minimising the
spread of HIV and hence AIDS
HIV is spread by exchanging infected
bodily fluids in sexual intercourse or sharing needles when
taking drugs e.g. HIV is transported in blood, semen and vaginal
So prevention measures to minimise the
spread of HIV disease include ...
(i) Using a condom during sexual
(ii) Drug users NOT sharing needles,
infections can be passed on from contaminated needles.
(iii) There are some medications (antiretroviral
drugs) available to reduce the risk of
passing on the infection during sex - this also applies to
mothers passing on the infection to babies during pregnancy.
(iv) Being screened and following up with
suitable treatment e.g.
drugs which stop the virus reproducing.