HIV

HIV
BY:- Katta Amulya
5th pharm-D
13AB1T0014
Department of Microbiology VPC - Vadlamudi…….
1

2
 History
 Orgin
 Epidemiology
 Morphology
 Pathogenesis
 Trasmission
 Signs and symptoms
 Diagnostic Tests
 Prophylaxis
 Treatment
OVERVIEW

What is HIV?
H -uman
• Found only in humans
• Transmitted among humans
• Preventable by humans
I -mmunodefiency
• Body lacks ability to fight off infections
V -irus
• Type of germ
• Lives and reproduces in body cells
3

“Human Immunodeficiency Virus”
A unique type of virus (a retrovirus)
Invades the helper T cells (CD4 cells) in the body of the
host (defense mechanism of a person)
Threatening a global epidemic.
Preventable, managable but not curable.
4

AIDS
A -cquired; received, not inherited (does not run
in families)
I -mmuno; protected from (in this case the
system protects the body from disease)
D -eficiency, - a lack of
S-yndrome; – a group of symptoms or diseases
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WHAT IS AIDS ?...!!
• “Acquired Immunodeficiency
Syndrome”
• HIV is the virus that causes AIDS
• Disease limits the body’s ability to fight
infection due to markedly reduced helper
T cells.
• Patients have a very weak immune system
(defense mechanism)
• Patients predisposed to multiple
opportunistic infections leading to death.
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Opportunistic infections and malignancies that rarely
occur in the absence of severe immunodeficiency (eg,
Pneumocystis pneumonia, central nervous system
lymphoma).
Persons with positive HIV serology who have ever had
a CD4 lymphocyte count below 200 cells/mcL or a CD4
lymphocyte percentage below 14% are considered to
have AIDS.
7

HISTORY
• AIDS was first clinically observed in 1981 in
the united states
• It was first identified in gay men with no
known cause of impaired immunity who
showed symptoms
• Now it has been reported virtuallyin every
country in the world
• Since more than 22 million people have died
of AIDS.
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ORIGIN
• Both HIV-1 & HIV-2 are believed to have
originated in non-human primates in
Africa & have transferred to humans in
20th century
• Chimpanzee is the source of HIV
transmission
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EPIDEMIOLOGY
• HIV/AIDS is a global pandemic
• As of 2012,approximately 35.3 million
people have HIV
• Of these approximately 16.8 million are
women & 3.4 million are less than 15
years old.
• South Africa has the largest population of
people with HIV of 5.9 million.
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GLOBAL ESTIMATES 2008
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HIV PREVALENCE IN VARIOUS REGIONS
4%
4%
3%
3%
2%
1%
1%
1%
18%
Source: UNAIDS, AIDS Epidemic Update, December 2004.
Total = 39.4 million
Sub-Saharan Africa
South/South-East Asia
Oceania
Caribbean
North Africa/Middle East
Western Europe
North America
East Asia
Eurasia
Latin America
<
42%
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“THE VIRAL GENOME”
• Icosahedral (20 sided), enveloped virus of
the lentivirus subfamily of retroviruses.
• Retroviruses transcribe RNA to DNA.
Two viral strands of RNA found in core
surrounded by protein outer coat.
Outer envelope contains a lipid
matrix within which specific viral
glycoproteins are imbedded.
These knob-like structures
responsible for binding to target
cell.
13

PATHOPHYSIOLOGY
• After the virus enters in to the body there
is a period of rapid viral replication,
leading to an abundance of virus in the
peripheral blood.
• Massive depletion of CD4+T cells
• CD8+ cell antiviral activity thought
it does not eliminate the virus
• HIV leads to AIDS
14

HIV is a virus that infects and destroys cells of the immune system (CD4+
cells).
http://aids.gov/hiv-aids-basics/hiv-aids-101/what-is-hiv-aids/
Approximately 8-10 years
Initial infection
Asymptomatic period
(clinical latency)
AIDS
Often (not always) accompanied by
severe flu like symptoms:
Opportunistic infections and cancer:
AIDS (acquired immunodeficiency syndrome) is the late-stage HIV disease. This
occurs when immune system becomes so damaged that it cannot fight off diseases
and certain types of cancer.
Department of Microbiology VPC - Vadlamudi……. 15

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Step 1: HIV targets T-cells to infect.

Step 2: HIVgp120 binds T-cell
CD4.
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Step 3: HIV inserts
RNA(black).
19

Step 4: Reverse Transcriptase
copies RNA to DNA (blue).
20

Step 5: DNA enters nucleus;
makes mRNA to encode HIV.
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Step 6: mRNA enters
cytoplasm to make
polypeptides (colors).
22

Step 7: HIV protease (green)
cuts and creates viral proteins.

Step 8: HIV prepares to pinch
out and break away from cell.
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Step 9: HIV pinches out
of cell.

Step 10: Mature HIV emerges
and infects other T-helper cells.

Modes of HIV/AIDS Transmission

Stage 1 - Primary
• Short, flu-like
illness - occurs one
to six weeks after
infection
• Mild symptoms
• Infected person
can infect other
people
30

Stage 2 - Asymptomatic
• Lasts for an average of ten years
• This stage is free from symptoms
• There may be swollen glands
• The level of HIV in the blood drops to
low levels
• HIV antibodies are detectable in the
blood

Stage 3 - Symptomatic
• The immune system deteriorates
• Opportunistic infections and cancers start to
appear.
32

Stage 4 - HIV  AIDS
• The immune
system weakens too
much as CD4 cells
decrease in number.
33

Opportunistic Infections associated
with AIDS
CD4<500
• Bacterial infections
• Tuberculosis (TB)
• Herpes Simplex
• Herpes Zoster
• Vaginal candidiasis
• Hairy leukoplakia
• Kaposi’s sarcoma
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Opportunistic Infections associated
with AIDS
CD4<200
• Pneumocystic carinii
• Toxoplasmosis
• Cryptococcosis
• Coccidiodomycosis
• Cryptosporiosis
• Non hodgkin’s
lymphoma

CD4 <50
• Disseminated mycobacterium avium complex
(MAC) infection
• Histoplasmosis
• CMV retinitis
• CNS lymphoma
• Progressive multifocal leukoencephalopathy
• HIV dementia

RESISTANCE
• Thermolabile
• Inactivated in 10 minutes at 60 degrees.
• Inactivated in 10 minutes when treated with 50%
Ethanol
• Inactivated at extremes of pH i.e, 1 and 13
37

Diagnosis
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Blood Detection Tests
HIV enzyme-linked immunosorbent
assay (ELISA)
Screening test for HIV
Sensitivity > 99.9%
Western blot Confirmatory test
Speicificity > 99.9% (when combined with
ELIZA)
HIV rapid antibody test Screening test for HIV
Simple to perform
Absolute CD4 lymphocyte count Predictor of HIV progression
Risk of opportunistic infections and AIDS
when <200
HIV viral load tests Best test for diagnosis of acute HIV
infection
Correlates with disease progression and
response to HAART

Urine Testing
• Urine Western Blot
– As sensitive as testing blood
– Safe way to screen for HIV
– Can cause false positives in
certain people at high risk for
HIV

Oral Testing
• Orasure
– The only FDA approved
HIV antibody.
– As accurate as blood
testing
– Draws blood-derived
fluids from the gum
tissue.
– NOT A SALIVA TEST!

HEALTH CARE FOLLOW UP
OF HIV INFECTED PATIENTS
For all HIV-infected individuals:
• CD4 counts every 3–6 months
• Viral load tests every 3–6 months and 1 month following a change in therapy
• PPD
• INH for those with positive PPD and normal chest radiograph
• RPR or VDRL for syphilis
• Toxoplasma IgG serology
• CMV IgG serology
• Pneumococcal vaccine
• Influenza vaccine in season
• Hepatitis B vaccine for those who are HBsAb-negative
• Haemophilus influenzae type b vaccination
• Papanicolaou smears every 6 months for women

PRIMARY PREVENTION:
Five ways to protect yourself?
• Monogamous Relationship
• Protected Sex
• Sterile needles
• New shaving/cutting blades

Monogamous relationship
• A mutually monogamous (only one sex partner)
relationship with a person who is not infected with
HIV
• HIV testing before intercourse is necessary to
prove your partner is not infected

Protected Sex
• Use condoms every time you
have sex
• Always use latex or
polyurethane condom (not a
natural skin condom)
• Always use a latex barrier
during oral sex

When Using A Condom Remember
?• Make sure the package is
not expired
• Make sure to check the
package for damages
• Do not open the package
with your teeth for risk of
tearing
• Never use the condom
more than once
• Use water-based rather than
oil-based condoms
Department of Microbiology VPC - Vadlamudi…….46

Treatment Options

Antiretroviral Drugs (HAART)
• Nucleoside Reverse Transcriptase inhibitors
– AZT (Zidovudine)
• Non-Nucleoside Transcriptase inhibitors
– Viramune (Nevirapine)
• Protease inhibitors
– Norvir (Ritonavir)

LIVING WITH HIV/AIDS
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Referrence
1. Ananthanarayan & Paniker’s , Text book of microbiology,7th edition,
2. R.Vasantha kumari, Text book of microbiology,1st edition,
3. Tortora , Funke , Case, Introduction of microbiology, 9thedition,
4.www.Wikipedia.com

HIV

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