Human 2017) Once In the cell it then
Human Immune-deficient virus (HIV) is extremely contagious. HIV spreads
through body fluids such as, seman, blood, breast milk and vaginal fluid (Human
Diseases and conditions, 2017). It can spread through sexual intercourse,
sharing needles, from mother to child with breast feeding and blood to blood
contact. (Alcorn,2001) Evidence suggests that AIDS, which develops from HIV,
originates from Africa from a virus named simian immunodeficiency (SIV) which
is found in monkeys. There are two types of HIV, HIV-1 and HIV-2. HIV 1 is virulent
and easy to transmit compared to HIV-2.
Human immune-deficient virus also known as HIV belongs to a retrovirus
family which is a group of viruses that replicate to make more copies, it attacks
the body’s immune system, especially CD4 cells (T Cells), which helps to fight
and defend off infections, these are known as T-lymphocytes (Gillespie,2013).
They help the immune system by performing tasks of fighting of diseases, With
HIV, the immune system weakens as it attacks our T-helper cells lock and key.(Human
Diseases and conditions, 2017) Once In the cell it then uses RNA as a template
to make copies of itself to then those copies to travel around the body. (Human
Diseases and conditions, 2017) Over time T cells count falls dramatically and
the host is now extremely more acceptable to picking up diseases. It takes HIV
10 years to develop into AIDS. (Penalva de oliveira,2015).
HIV-1 is composed of two
unspliced single stranded RNA which is enclosed by a capsid of viral protein.
Single stranded RNA is tightly bounded to nucleocaspid proteins. HIV -1 is an
enveloped RNA virus. As HIV buds away from the host cell during replication, it
then forms a phospholipid envelope, protruding from the envelope is a peg like
structures that viral RNA encodes (Annenberg Learner, 2013). Each peg has three
or four glycoproteins (gp120,gp41 and gp160), inside the envelope the
nucleocaspid of the virus is composed of a protein which is encloses two single
strands RNA with reverse transcriptase attached, In the single strand.
HIV enters the host and
binds to a host cell through lock and key which then the viral envelope fuses
with the cell membrane, allowing HIV’s RNA and enzymes to enter the cytoplasm.
It contains an enzyme known as reverse transcriptase which allows the single
stranded RNA of the virus to be copied and double stranded (Annenberg Learner,
2013). An enzyme known as integrase then facilitates the viral DNA into the
There are three stages when it comes to
HIV. First stage is Acute HIV infection stage, which is 2 to 4 weeks after
infection a lot of people will experience or develop the flu like symptoms,
such as fever sore throat etc. This is known as ‘acute retroviral syndrome’
(Gillespie, 2014). This is a result of the body’s natural response to the
infection. The virus in the early stage uses CD4 cells to replicate and destroy
them in the process. (HIV.Gov, 2017), However eventually the immune response
will bring the level of virus to a viral set point, which is a stable level of
virus in the body. This is where CD4 begin the increase. During the acute stage
the person is at high risk of transmitting the infection.
Next stage of HIV is clinical latency
stage, is where the virus is living in a person without showing signs of symptoms.
HIV continues to reproduce at low levels. Final stage is Aids, where the immune
system is badly damaged and vulnerable to opportunistic infections. Once the
numbers of CD4 cells drop below 200 cells per cubic millimeter of blood, it is
then considered that the person has progresses to aids. Meaning more likely to
fall ill with an opportunistic illness. (HIV.Gov,2017).
A treatment known as
Antiretroviral therapy (ART) is used to treat HIV. It is recommended to
everyone who has HIV. (Aids.info,2008) Although it won’t cure HIV but it will
however let people with HIV live healthy lives. (Aids.info,2008) The medicine
will prevent HIV from multiplying therefore reducing the amount of HIV in the
body. There will be some remaining HIV in the body but the immune system is
strong enough to fight of infections. (Aids.info,2008) By taking the ART
therapy is also reduces the risk of transmission.
Elisa is one of the techniques
used to detect HIV. The person who Is being tested on, will give a blood
sample, this blood sample will be looked at in detail with antibody testing, if
the person has been infected with HIV the antibodies within the serum will bind
to the HIV proteins. (Gompf,2011)However, there is a small chance that the
person’s antibodies could falsely attach themselves to the non-HIV proteins. Another
test is the western blot test; HIV proteins are separated by size and charge with
the person’s serum within the test strip, is test comes out positive the series
of bands are detected which shows binding of person’s antibody to HIV virus
HIV RNA testing is used to
estimate the amount of HIV within the blood, known as HIV viral load. (Gompf,2011)
PCR is used, these tests are used more in new born with screening mothers who
are positive for HIV as antibodies from the mother can cross the placenta.
HIV antibody-antigen test-
this detects HIV-1 or HIV-2 and a protein called P24 which is the antigen of
the virus.(Gompf,2011) It takes weeks for antibodies to form infection meaning
that antibody-antigen testing allows for earlier detection of HIV. If either
the antibody or antigen is present, the test reaction emits light on the