Transcript Virology

HIV/AIDS
Human Immunodeficiency Virus
Acquired Immunodeficiency Syndrome
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AIDS is Caused by HIV
Is the one common denominator within a
range of populations.
 Has been identified by electron
microscopy.
 Antibodies, viral antigens, and HIV RNA
have been found in HIV-Positive and AIDS
patients.
 Many others
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More Origins of HIV
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Unidentified Flying Objects (UFO’s) coming from space
Is a biological weapon designed to kill non-whites.
Came from domestic cats. (Feline AIDS is similar to
Human AIDS)
HIV Contaminated _______ vaccines.
Polio
Smallpox
Tetanus
Hepatitis
African Green Monkey
 African People
 African Cattle, Pigs, Sheep
 CIA and other spy agencies
 Biological Weapons Labs
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Current Theory
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Hahn et al. (1999, 2000)
Simian virus closely related to HIV jumped from chimps
to humans .
Virus then mutated into its current form.
Evidence
– Genes from all four SIVcpz isolates cluster to their subspecies or
origin
 Pan Troglodytes Troglodytes - West Africa
 Pan Trogldytes Scheinfurthii - East Africa
– All known HIV-1 strains cluster with W. Africa Chimp viruses
– Evidence of genetic recombination among SIVcpz strains of the
Troglodytes lineage.
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Newer evidence indicates multiple jumpings – different
strains
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Example

HIV Strains have 11 distinct subtypes
– A-K
– Subtype B is dominant in US and Europe
– Subtype D is dominant in Africa
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Virus mutates rapidly.
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United States HIV History

Virus has been in the US since mid. 1970’s.
– 1979-1981
– Physicians in New York and Los Angeles began
reporting particular diseases in Gay males.
– Including:
 Rare Pneumonias
 Cancers
 Other diseases
– Diseases were not usually found in people with
healthy immune systems.
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1982

Public Health begins using term Acquired
Immunodeficiency Syndrome (AIDS) to describe
opportunistic infections in previously healthy
men.
– Including
 Kaposi’s Sarcoma
 Pneumocystis Carni Pneumonia

Surveillance of AIDS begins
Diagnosis of cellular immune deficiency
Absence of an underlying cause
Reduced resistance to the disease
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HIV Surveillance
Definition modified in 1983
 Required to be reported to CDC
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1983
First cases of AIDS in heterosexuals are documented.
 Virus is isolated by various labs.
 Named

– HTLV-III (Human T-Lymphotrophic Virus-III)
(Gallo)
– LAV
(Lymphadenopathy Associated Virus)
(Luc Montagnier Mont-Tan-Ya)
– ARV
(AIDS – Related Virus)
Ultimately named
– HIV
(Human Immunodeficiency Virus)
(Sub-committee of the Committee on the Taxonomy of
Viruses
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1985
Second type of HIV discovered
– HIV-2
 Related to SIV
 Not as related to HIV-1
 Does not seem as harmful as HIV-1
 Reproduces slower than HIV-1
 Screening tests become available
 Tests of stored blood samples indicate HIV was
being transmitted in US and Europe in mid to
late 1970’s.
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Early Definitions of AIDS
1981-93
Many definitions of AIDS
 Problem
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– Social Security Administration (SSA)
– Used AIDS definition to determine disability
 Symptoms were based on opportunistic infections
in men.
– Result
 65% of women were excluded
 Other problems too
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1993
New definition of AIDS
 Emphasized the importance of T4 lymphocyte
counts.
 Added other diseases
 System becomes simpler
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Also allowed one to become diagnosed with
AIDS but remain symptom-free of diseases.
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1987
First case of HIV-2 in the U.S.
 First Anti - HIV drugs become available
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– Zidovudine (AZT)
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1988
Protease Inhibitors are identified.
 Have problems with

– Absorption
– Have rapid liver metabolism
– Insolubility
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Result – More development and clinical
trials.
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1992
Protease Inhibitors (PI) become more developed
 First - Saquinavir Mesylate (Invirase)
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–
–
–
–
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Was used in combination with other drugs
Minimal clinical trial data
Had poor absorption
Was the least potent of other PI’s that came on the
market later.
Second – Ritonavir (Norvir)
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More Protease Inhibitors are Developed
Saquinavir
(Fortovase)
Indinavir
(Crixivan)
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Nelfinavir
Amprenavir
ABT – 378
(Viracept)
(Agenerase)
(Kaletra)
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Problem

– More easily absorbed by the body
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– Most often used
– Drugs are expensive $450-$700/month
– = $5,400 - $8,400/yr
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2000
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Drug Combinations (Cocktails)
– Uses multiple combinations of drugs
– Called Highly Active Antiretroviral Therapy
(HAART)
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2001
Negotiations to reduce costs
 Generics are developed by outside
countries despite patent laws.

– Is a major problem
Costs go down
 Drug companies reevaluate staying in the
HIV drug market
 When do you use (early vs. later)
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Present
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HIV continues to mutate
– Currently getting HIV resistance to
drugs
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People are returning to previous lifestyles
– Drugs are effective at helping people
– Can work
– Enjoy life
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Also
People are not taking drug combinations so they effectively block the
virus
–
Monotherapy
People also stop taking drugs when they do not have money
People stop taking drugs when they are feeling better
People who are infected are having sex with other infected individuals
Has spread into the IDU community which is spreading it into the
general heterosexual population.
Result
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1. Drug Resistance
30% of newly infected individuals have
viral forms that resistant to at least one
drug.
 Drug resistant strains are becoming more
powerful
 Result – Salvage therapy

– Give everything you can
– 30-50% of HIV infected persons are in such
therapy.
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2. New Strains
Are more powerful than previous strains
 Cause individuals who are doing well on
drug cocktails to become ill again
 Has caused us to reevaluate the issues of
vaccines
 Is going to become a real problem
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Conclusions and Issues
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HIV is a Unique Disease
Affects mostly young and middle aged
adults.
 Are sexually active
 Are in their prime productive and
reproductive years
 Impact is demographic, economic,
political, and social.
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Problem
Have forgotten the past
 STD rates are increasing again in some
communities
 1999-2002 number of males with new HIV
infections increased 7.3% (CDC, 2003)
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– Among MSMs increased 17%
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HIV Is A Preventable Disease
To stop the disease, must change the
behavior.
 Is a system of numbers.
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– More people in a population that have it,
– The greater the likelihood YOU (or your offspring) will
get it.
1/100 vs. 10/100 vs. 25/100 vs. 50/100
1/100
1/10
1/4
1/2
1%
10%
25%
50%
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