Human immunodeficiency virus

WHAT IS HIV ?
Human Immunodeficiency Virus
H = Infects only Human beings
I = Immunodeficiency virus weakens the immune
system and increases the risk of infection
V = Virus that attacks the body and eventually
overcomes the body’s immune system 2

HIV:
 HIV belongs to a special class of viruses called
retroviruses. Within this class, HIV is placed in
the subgroup of lentiviruses
 All viruses except retroviruses contain DNA
 Other lentiviruses include SIV, FIV, Visna and
CAEV, which cause diseases in monkeys, cats,
sheep and goats.
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 HIV particles surround themselves with a coat of fatty
material known as the viral envelope .
 This envelope gives out lots of little spikes around 72 in
number.
 These spikes are made of knobs and handles made of
proteins gp120 and gp41 respectively.
 Just below the viral envelope is a layer called the matrix,
which is made from the protein p17(Matrix proteins)
 Below the matrix is another layer of proteins P24 forming
viral core (or capsid) and is usually bullet-shaped.
 Inside the core are three enzymes required for HIV
replication called Reverse transcriptase,Integrase and
protease
 Also held within the core is HIV's genetic material, which
consists of two identical copies of single stranded RNA 5

CAUSES OF HIV :
 The HIV infection is caused by the human
immunodeficiency virus (HIV).
 After HIV is in the body, it starts to destroy CD4+T
cells, which are white blood cells that help the body fight
infection and disease.
 HIV is spread when blood, semen, or vaginal fluids
from an infected person enter another person's body,
usually through sexual contact, from sharing needles
when injecting drugs, or from mother to baby during
birth 6

PATHOGENESIS :
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 Attachment of virus at the CD4 receptor and
chemokine co-receptors .
 viral fusion and uncoating
 Reverse transcriptase .
 Migration to nucleus
 Integration of the viral DNA into cellular DNA by the
enzyme integrase
 Transcription and RNA processing
 Protein synthesis.
 protease cleaves polypeptides into functional HIV
proteins and the virion assembles
 virion budding
 Virion maturation

STAGE 1 – PRIMARY :
 flu like illness - occurs two to six weeks after
infection or there may be
 no symptoms at all
 Infected person can infect other people
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 This stage is free from symptoms
 There may be swollen glands.
 HIV antibodies are detectable in the blood
 This stage is last for about ten years
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Stage 2 - Asymptomatic

STAGE 3 – SYMPTOMATIC :
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The person starts showing symptoms like fever,
skin disease.
The immune system deteriorates emergence of
opportunistic infections and cancers

STAGE 4 - HIV  AIDS :
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 The immune system weakens
 The illnesses become more severe leading to
AIDS
 The illnesses become more severe leading to
emergence of opportunistic infections and
cancers

TRANSMISSION OF HIV VIRUS:
 HIV virus is passed from one person to another
through blood-to-blood and unprotected sex.
 In addition, infected pregnant women can pass
HIV to their baby during pregnancy or delivery,
as well as through breast-feeding.
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 The body fluids have been proven to spread HIV:
• blood
• semen
• vaginal fluid
• breast milk
• other body fluids containing blood
• cerebrospinal fluid surrounding the brain and the
spinal cord
• synovial fluid surrounding bone joints
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SYMPTOMS :
The symptoms of this :
 diarrhea
 fatigue or weakness
 fever
 headache
 joint pain
 night sweats
 rash
 swollen glands
 weight loss
 yeast infections (of the mouth or vagina) that last a long time or
occur frequently
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THE ACUTE HIV SYNDROME
Follows 3-6 wks following primary infection

LABORATORY TEST
TO DIAGNOSE HIV
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 Enzyme-Linked Immunosorbent Assay/Enzyme
Immunoassay (ELISA/EIA)
 Western Blot
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HIGHLY ACTIVE ANTIRETROVIRAL DRUGS
 NUCLEOSIDE REVERSE TRANSCRIPTASE
Zidovudine
Stavudine
 NON-NUCLEOSIDE REVERSE TRANSCRIPTASE
INHIBITOR
Efavirenz
Nevirapine
 PROTEASE INHIBITOR
Atazanavir
Darunavir
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There's no vaccine to prevent HIV
infection and no cure for AIDS. But
it's possible to protect yourself and
others from infection. That means
educating yourself about HIV and
avoiding any behavior that allows
HIV-infected fluids — blood, semen,
vaginal secretions and breast milk
— into your body.
PREVENTION
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HIV-NEGATIVE INDIVIDUAL PREVENTION:
Educate yourself and others.
Use a clean needle.
Be cautious about blood products.
Get regular screening tests
Use condoms when having sex
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HIV POSITIVE INDIVIDUAL PREVENTION:
Follow safe-sex practices.
Don't share needles or syringes.
Don't donate blood or organs.
Anti Retro Viral treatment
If pregnant, get medical care right away.
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Human immunodeficiency virus

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