HIV/AIDS
Melissa Schreiber
Overview
• What is AIDS: Origin and Scope?
– Prevalence of AIDS
– The Epidemiology ands AIDS Demographic
– Transmission of HIV
• Phases of an HIV Infection
• HIV Structure and Life Cycle
• Drug Therapy for HIV Infection
– Prevention and Treatment
– Living with HIV or AIDS
Origin of HIV/AIDS
• Originated in Africa and spread to the
US and Europe
• Found preserved 1959 blood sample
• Humans may have ate nonhuman
primates for meat and mutated to HIV
• AIDS was coined in 1982
• HIV was found to be the cause of AIDS
in 1983-84
HIV/AIDS
• Human Immunodeficiency Virus (HIV)
– Immune system deficient, cannot resist disease
– Virus responsible for Acquired Immune Deficiency
Syndrome (AIDS)
• Acquired Immune Deficiency Syndrome
(AIDS)
– Descriptive of the infection and it’s progression
– First observed in U.S. cities in early 1980s
– Young, healthy men dying of rare diseases
Definition of AIDS
• Positive blood test indicating the
presence if HIV antibodies
– T-cell count below 200
– If T-cell count is higher than 200, he or she
must have one or more of the opportunistic
infections or conditions associated with
AIDS
• If a person has HIV antibodies, but does
not meet the other criteria, classified
“have HIV,” “be HIV-positive,” “be HIV
infected,” or “be living with HIV”
Opportunistic Infections of AIDS
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Symptoms of HIV Infection and AIDS
• Unexplained persistent
fatigue
• Fever, chills, night
sweats
• Unexplained weight
loss
• Swollen lymph nodes
• Pink, red, purple, or
brown blotches
• Persistent dry cough
• Persistent, fuzzy, white
spots in mouth, tongue,
or throat
• Memory loss or
depression
• Abnormal pap smears
• Persistent vaginal
candidiasis
• Abdominal cramping
(due to Pelvic
inflammatory Disease)
• Persistent Diarrhea
Epidemiology and Transmission of HIV
• Epidemiology – study of the incidence,
process, distribution, and control of
diseases
• Epidemic – wide and rapid spread of a
contagious disease
• World Health Organization reports 25
million people have died from AIDS
• Estimated that 40.3 million people are
living with HIV
Epidemiology and Transmission of HIV
• Global increases in number of people
living with AIDS
• African continent the largest
concentration
• 2/3 of all AIDS cases are in SubSaharan Africa
• 77% of women living with AIDS are in
Sub-Saharan Africa
Epidemiology and Transmission
of HIV in the United States
• Through 2004, CDC reports 944, 000
individuals had lived with AIDS
• End of 2004, 400,000 people were
living with AIDS
• 40,000 cases are diagnosed annually
• Changes in current transmission
modes
• Changes across ethnic groups
AIDS Differs by Gender, 2003
Change in AIDS Cases by
Race/Ethnicity
U.S. AIDS Cases by Race/Ethnicity,
2003
Modes of Transmission
• Sexual transmission: anal and vaginal
intercourse, and oral sex
• Injection drug and substance abuse:
sharing needles
• Mother-to-child transmission: passing
virus from mother to fetus, breast-feeding
• Blood transfusions: contaminated blood
transfusions or organ transplants
performed before April 1, 1985
Primary Sources and Possible Routes of Infection by HIV
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Changes in Transmission Category
The Immune System and HIV
• Leukocytes – white blood cells
• Play major roles in defending the body against invading
organisms or cancerous cells
• Macrophages
• Engulf foreign particles and displays the invader’s
antigens
• Antigens
• Stimulate immune system, react with antibodies
• Antibodies
• Inactivate antigens, mark them for destruction
• B cells and T cells (Lymphocytes)
• Helper T cells and killer T cells
Effect on T Cells
• HIV enters the bloodstream, helper T
cells rush to the invading viruses
• Immune process starts to break down
• HIV injects its contents into the host T
cell
• Copies its own genetic code, RNA, into
the cell’s genetic material (DNA)
• Immune system is activated and the T
cell begins producing HIV instead of
replicating itself
How the Disease Progresses
• T-cell (CD4) count: # of helper T cells
present in cubic mL of blood
• Viral load counts
• Phases of infection
– Months to years
– Early flu-like symptoms
• AIDS
• Death
Phases of an HIV Infection
• Category A: Acute Phase
– T helper cells above 500 per mm3
– Viral load: # of HIV particles in the blood
• Category B: Chronic Phase
– T helper cells 200 to 499 per mm3 of blood
– HIV virus increases
• Category C: AIDS
– T helper cells fallen below 200 per mm3
– Opportunistic infection
General Pattern of HIV Infection
HIV Virus
• Protein coated package of genes that invades
a cell and alters the way in which the cell
reproduces itself
• Host dependent
• GP 120: antigens on HIV that attract the CD4
receptors on helper T cells
• Within virus’s protein core
– Genetic material (RNA)
– Enzyme, reverse transcriptase
• Retrovirus – reverses the normal genetic
writing process
Infection of a CD4 T Cell by HIV
Minority Races/Ethnicities and HIV
• In the early 80s, was viewed as a
disease in whites and gays
• Currently identified in all ethnic groups
• Occurs in groups with
– Poverty
– Lack of access to or willingness to use
health care
– Substance abuse
Minority Races/Ethnicities and HIV
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African Americans
Hispanics
Asian Americans/Pacific Islanders
American Indians and Alaska
Natives
The Gay Community
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Men who have sex with men
Stigma slowed prevention efforts
Special consideration of ethnic groups
Psychological long term effects
Increased risk taking
Other STIs
U.S. AIDS Demographics by gender
Other Groups and HIV
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Women and HIV
Children and HIV
Teens and College Students and HIV
Older adults and HIV
Geographic Region and HIV
Prevention of HIV/AIDS
• Protecting Ourselves
– Be aware that alcohol and drug use
increases risky behaviors
– Develop communication skills to be able
to discuss risks and prevention with
partners
– Use HIV testing and make appropriate
decisions
– Use condoms
Prevention of HIV/AIDS
• Saving lives through prevention
– Reduced new infections from
150,000/year to 40,000/year
• Obstacles to prevention: blame and
denial
– AIDS seen as disease of marginalized
group, not “us”
• Needle exchange programs
• HIV testing
HIV Testing
• Tests should be taken 12 weeks after highrisk behavior, repeated 6 months after an
uncertain result
• Types of Tests
– ELISA: enzyme-linked immunosorbent assay
– Western Blot: rechecks ELISA results
– Viral load tests measure HIV in bloodstream
(PCR)
• Getting Tested
• Partner Notification
Treatment
• Antiretroviral Medications
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Nonnucleoside reverse transcriptase inhibitors
Nucleoside reverse transcriptase inhibitors
Protease inhibitors
Fusion Inhibitor
• HAART – Highly Active Antiretroviral
Therapy
– Combination of three or more medications
• Atripla – newest antiretroviral
– Combination of three medications in one pill
– Lowers the amount of HIV (called viral load) by
interfering with the way HIV makes copies of itself
Living with HIV or AIDS
• If You Are HIV Positive
–Taking care of your health
–Addressing your other needs
–If you are caring for someone
with HIV or AIDS
Summary
• What is AIDS: Origin and Scope?
– Prevalence of AIDS
– The Epidemiology and Transmission of HIV
– AIDS Demographic
• Phases of an HIV Infection
• HIV Structure and Life Cycle
• Drug Therapy for HIV Infection
– Prevention and Treatment
– Living with HIV or AIDS